Today marks the last day of the last week of the experiment. As is tradition, we debriefed the EWP visiting forecasters on their experiences throughout the week...
Convective Initiation
- (Thursday event - N.E.) Cloud-top cooling products seemed to work in diagnosing the strength of storms on the southwest edge of the line that were newly developing.
- Even though CI didn't always occur... false hits were useful in identifying clouds trying to break the cap.
- Forecasters not interested in seeing a binary yes/no output.
- "There were instances where similar looking clumps of Cu that one would flag for CI but the other wouldn't... so I wasn't sure how to interpret that other than maybe this area was more conducive to further development."
- There are lots of products that provide you lead time on CI, the real question would be on the consistency of the output.
- "I would definitely look at this in my WFO... especially the cooling-tops product gave me a lot of information on the relative strengths of the storms."
- "If both groups could work together and come up with a probabilistic product that combined the strengths of the UAH and the UWCI products, that would be very useful."
- "I think from a purely public forecast perspective, especially this time of year where we get convection every day, it would help you identify when exactly CI will occur."
- Would be very valuable for nocturnal CI.
Nearcast
- (Thursday event - N.E.) "I didn't see a whole lot of trend in terms of gradients developing, but all the sudden on the back side of the squall-line we lost data rapidly, probably due to cloud cover... compared to the other days, I didn't see any real patterns."
- (Thursday event - KS/OK) Showed an arch of destabilization between 2200-0300 across the eastern halves of OK and KS... storms formed on the western edge of this gradient and forecaster did not expect the storms to diminish anytime soon and thus increased warning confidence... stronger wording regarding hail/wind potential in warning was issued.
- There seemed to be small scale features in the fields, areas of relative maximum that were moving around... would be nice to compare to radar evolution and see how those areas affected the storm structure.
- Helped understand why convection occurred and where it would occur... definitely the 1-6 or 1-9 hour timeframe was the most useful aspect of it.
- Having a 4-panel set up of the individual layers in addition to the difference field to help increase the understanding of the product.
- The color-table in AWIPS was poor... Also, the values were reversed from those in NAWIPS and on the web. The individual layers of PW were also not available in AWIPS.
Would it be useful to extend the Nearcast another 3 hours, even if that meant smoother fields?
- "I like the high resolution out to whenever we can have it... it seemed that there was definitely information within the gradients... of course if you add 3 hours, we will definitely take that."
Would you have used the observations without it being advected forward?
- Wouldn't have been as useful... It helped determine the evolution of the environment... The forecast parts tended to build areas of increased instability that helped provide guidance on what was going to happen later on.
Overshooting-top / Thermal Couplet
- (Thursday event - KS/OK) None were detected when forecasters expected to see detections, so was not used, especially with the rapid updates of radar data.
- Need to remember to turn icon density to "MAX" within AWIPS or some detections will be lost.
- Looked at pretty much every day... for the most part, operator identified OTs occurred before the algorithm did.
Pseudo-GLM
- (Thursday event - OK) Some of the storms to the east had higher flash rates, but this was an artifact of the LMA network's detection efficiencies.
- (Thursday event - OK) Flash rates would pick up a short time before increases in reflectivity.
- Was useful for diagnosing lightning danger... get a lot of calls from the public regarding that within the WFO.
Overall
- Would definitely help to have some pre-configured procedures before forecasters arrived... forecasters used the "ultimate CI" procedure heavily and liked to see what we think they should be combining to help enhance the utility of the products. Forecasters can then adjust the color-scales for their own preferences.
- "I liked the morning/evening shift idea... that was nice... got to experience something different everyday."
- Sometimes the forecasters would get to tied into warning operations mode and forget to look at the experimental products... would be nice to make sure that the forecasters understand that there is no real pressure and to take their time to examine all of the experimental stuff.
- Would have been useful to provide the forecasters with the training via visitview prior to arrival, as well as some cases that the forecasters could use to get familiar with the products and decrease spin-up time... This would have to be done very far in advance.
- Interaction with the EFP CI desk was not done because there were so many participants over in the area.
- EFP/EWP daily briefing was seen to be repetitive between all the groups and not very "brief" as one forecaster stated. Also, the information being provided was more academic than pure weather discussion.
- WE NEED MORE CHAIRS!
Showing posts with label Pseudo-GLM total lightning. Show all posts
Showing posts with label Pseudo-GLM total lightning. Show all posts
Friday, June 10, 2011
Thursday, June 9, 2011
Utilizing PGLM and Nearcast in warning ops
Forecasters are once again engaged in warning operations within the EWP's evening activities. Bill Bunting (MIC DFW) is currently using the PGLM instantaneous flash extent density, as well as the Nearcast differential theta-e products while issuing warnings for storms over NW OK (see image above). Like forecasters from previous weeks, the Nearcast differential theta-e field provides information on near-storm convective instability and can provide the forecaster with confidence on whether or not the storms are expected to intensify or dissipate. Currently the PGLM is showing healthy flash densities, while the NLDN is only showing sparse CG activity within the storms.
This week in lightning safety...
There were a couple news stories this week that caught my interest regarding the weather that are directly applicable to what we are trying to do here within the HWT with the Psuedo-GLM data. On Wednesday afternoon, 77 Air Force ROTC students were struck by lightning on a military base near Hattiesburg, MS...
http://www.cnn.com/2011/US/06/08/mississippi.lightning/index.html?npt=NP1
Below is another story about a man who was thrown 8 feet by a lightning strike on Tuesday night in Morganton, NC. There is an interesting quote from the story that points out the particular dangers in trying to anticipate lightning threats... "According to Davis, the sun was still out and the storm appeared to still be about ten to 15 miles away."
http://morganton.wbtv.com/news/people/man-struck-lightning-thrown-eight-feet/63485?hpt=us_bn5
I am very grateful that no one was killed in these events, and I would like to repost a blog entry written by NASA SPoRT scientist Geoffrey Stano from a couple weeks ago regarding the use of the GLM and lightning safety... READ HERE.
Also, Geoffrey Stano posted about how total lightning measurements of in-cloud flashes preceded the first occurrence of a cloud-to-ground strike... READ HERE.
It will be interesting to see how the GLM data are used within NWS operations for possible lightning safety forecasts in the future.
http://www.cnn.com/2011/US/06/08/mississippi.lightning/index.html?npt=NP1
Below is another story about a man who was thrown 8 feet by a lightning strike on Tuesday night in Morganton, NC. There is an interesting quote from the story that points out the particular dangers in trying to anticipate lightning threats... "According to Davis, the sun was still out and the storm appeared to still be about ten to 15 miles away."
http://morganton.wbtv.com/news/people/man-struck-lightning-thrown-eight-feet/63485?hpt=us_bn5
I am very grateful that no one was killed in these events, and I would like to repost a blog entry written by NASA SPoRT scientist Geoffrey Stano from a couple weeks ago regarding the use of the GLM and lightning safety... READ HERE.
Also, Geoffrey Stano posted about how total lightning measurements of in-cloud flashes preceded the first occurrence of a cloud-to-ground strike... READ HERE.
It will be interesting to see how the GLM data are used within NWS operations for possible lightning safety forecasts in the future.
Friday, May 27, 2011
End of week debrief... 27 May
Today we had our end of week debrief for the EWP. We did have a fairly robust discussion yesterday regarding the 24 May event, so we tried to gather some additional information from the forecasters. We covered each of the products and how they performed within warning operations this week.
Convective Initiation
- (26 May event) CI did not so well over AL/TN... high FAR, low POD in morning... Forecaster theorized this may have something to do with the less dramatic temperature differences between the surface and clouds during the morning hours.
- CI did much better during rapid scan.
- The UAH version was much more agressive that the UW version.
- Having a probabilistic approach versus a yes/no would help.
- Forecaster used the UW CTC/CI product to issue a severe weather statement... ended up putting a warning on it afterwards.
- This could be important for not just severe weather... the CI products could be very useful for the onset of lightning as sort of a proxy for the growth of a certain dBZ threshold above say a -10 C level if it had faster updates.
- "I'm assuming that performance should improve pretty dramatically once you get the rapid updates with the next-generation satellites, but now I guess it would work best in a clean environment in the plains. I could also see the probabilities a good way to go."
- Maybe contouring SATCAST probabilities would be a good.
- "Based on what it's designed to do, I can see this working in a typical summer afternoon in Florida, not just over the plains."
- Could help identify waterspout candidates because they're harder to see on radar.
- For non-severe faster moving systems it may be useful in detecting regions of heavy rain.
- Would be a good idea to get west coast offices to look at these things since they rely heavily on satellite data because of a lack of surface observations.
Pseudo-GLM
- When we saw cell mergers there was a rapid increase in flash rate over a 5 minute time period and updraft speed from the 3D-VAR analysis.
- A lot of times we would have flash rate increases over the anvil areas downstream... it could help you focus on the new electrification of the storm as well as where new cells might develop or updrafts cores move... would give 10-15 minutes lead time before it showed on radar.
- 10-15 minutes lead time on the first CG.
- "There's a lot of potential use for these types of products... but there is definitely more room for improvement with additional research, as well as increased temporal or spatial resolution."
- It may be difficult to display the rate of change product, not everyone will be looking at the same storm, so having a gridded history would be really useful that you could click on and get an idea of how that storm has evolved.
- Having polarity information would be very useful.
- "Need more research on the forecasting applications of this data."
- Would be interesting to see the PGLM over mini-supercells as well as some winter cases looking at rainfall rates and updraft strengths.
- Ratio of IC-CG would be very useful... being able to query a cell or cluster for it's trend would be helpful.
- The classic MCCs, it would be interesting to see how that related to severe and heavy rain potential.
- Using the PGLM might be useful for a poor man's microwave information in distinguishing areas of convective and trailing stratiform.
- Would have a lot of utility in mountainous regions where flash flooding is a big issue, especially if there is no radar coverage.
- The sum product was not very useful, mainly because of the color scale... everything becomes white... Forecaster used it as a sort of storm total tool, much like precip.
Overshooting-top / Thermal Couplet
- (26 May event) One couplet was over some leading cells along the PN/MD line... the clouds behind that were masked by cirrus and may have limited the detection. When it did trigger, it well differentiated that cell from the rest of the scene.
Nearcast
- (26 May event) The theta-e and precipitable water differences really indicated the marginality of the storms in the foothills... where the maximum stuff intersected that is where we saw the most sustained convection and highest flash rates. It was definitely a good indicator of flash flooding over the area.
- "A lot of the time to increase my lead time in the morning, I like to take a look at PW and WV... so I found that this was a nice utility because it was indicative of finding areas of greatly deep instability, or moisture source regions."
- "One on storm on tuesday, there was strong theta-e gradient that the storm was moving into and that gave me confidence in that the storm would intensify."
- It's a simple way to identify areas of warm advection and instability... this is why the forecaster found it useful in warning operations.
NSSL-WRF Band Difference
- The band difference has a lot of potential... you can get a head start by looking at the trends in the data that help you anticipate what's going to happen.
Overall
- "I enjoyed seeing the combination of the satellite products interacting with the radar and lightning products... it's a great planning tool."
- Need to come up with some pre-made default procedures for the experimental products... it's tough for forecasters to come in cold and learn how to load all of the products and then go into forecasting operations. The forecasters especially applauded the creation of the "ultimate-CI" procedure from last week and that should be saved.
- Create articulate presentations that forecasters can view beforehand rather than having "powerpoint death" on Mondays... this will also maximize the time forecasters have to look at the products.
- Would also be useful to create very short WES cases to send out beforehand that the forecasters can go through before they arrive.
- Forecaster would like to see the derived sounder products within the HWT AWIPS next year.
Convective Initiation
- (26 May event) CI did not so well over AL/TN... high FAR, low POD in morning... Forecaster theorized this may have something to do with the less dramatic temperature differences between the surface and clouds during the morning hours.
- CI did much better during rapid scan.
- The UAH version was much more agressive that the UW version.
- Having a probabilistic approach versus a yes/no would help.
- Forecaster used the UW CTC/CI product to issue a severe weather statement... ended up putting a warning on it afterwards.
- This could be important for not just severe weather... the CI products could be very useful for the onset of lightning as sort of a proxy for the growth of a certain dBZ threshold above say a -10 C level if it had faster updates.
- "I'm assuming that performance should improve pretty dramatically once you get the rapid updates with the next-generation satellites, but now I guess it would work best in a clean environment in the plains. I could also see the probabilities a good way to go."
- Maybe contouring SATCAST probabilities would be a good.
- "Based on what it's designed to do, I can see this working in a typical summer afternoon in Florida, not just over the plains."
- Could help identify waterspout candidates because they're harder to see on radar.
- For non-severe faster moving systems it may be useful in detecting regions of heavy rain.
- Would be a good idea to get west coast offices to look at these things since they rely heavily on satellite data because of a lack of surface observations.
Pseudo-GLM
- When we saw cell mergers there was a rapid increase in flash rate over a 5 minute time period and updraft speed from the 3D-VAR analysis.
- A lot of times we would have flash rate increases over the anvil areas downstream... it could help you focus on the new electrification of the storm as well as where new cells might develop or updrafts cores move... would give 10-15 minutes lead time before it showed on radar.
- 10-15 minutes lead time on the first CG.
- "There's a lot of potential use for these types of products... but there is definitely more room for improvement with additional research, as well as increased temporal or spatial resolution."
- It may be difficult to display the rate of change product, not everyone will be looking at the same storm, so having a gridded history would be really useful that you could click on and get an idea of how that storm has evolved.
- Having polarity information would be very useful.
- "Need more research on the forecasting applications of this data."
- Would be interesting to see the PGLM over mini-supercells as well as some winter cases looking at rainfall rates and updraft strengths.
- Ratio of IC-CG would be very useful... being able to query a cell or cluster for it's trend would be helpful.
- The classic MCCs, it would be interesting to see how that related to severe and heavy rain potential.
- Using the PGLM might be useful for a poor man's microwave information in distinguishing areas of convective and trailing stratiform.
- Would have a lot of utility in mountainous regions where flash flooding is a big issue, especially if there is no radar coverage.
- The sum product was not very useful, mainly because of the color scale... everything becomes white... Forecaster used it as a sort of storm total tool, much like precip.
Overshooting-top / Thermal Couplet
- (26 May event) One couplet was over some leading cells along the PN/MD line... the clouds behind that were masked by cirrus and may have limited the detection. When it did trigger, it well differentiated that cell from the rest of the scene.
Nearcast
- (26 May event) The theta-e and precipitable water differences really indicated the marginality of the storms in the foothills... where the maximum stuff intersected that is where we saw the most sustained convection and highest flash rates. It was definitely a good indicator of flash flooding over the area.
- "A lot of the time to increase my lead time in the morning, I like to take a look at PW and WV... so I found that this was a nice utility because it was indicative of finding areas of greatly deep instability, or moisture source regions."
- "One on storm on tuesday, there was strong theta-e gradient that the storm was moving into and that gave me confidence in that the storm would intensify."
- It's a simple way to identify areas of warm advection and instability... this is why the forecaster found it useful in warning operations.
NSSL-WRF Band Difference
- The band difference has a lot of potential... you can get a head start by looking at the trends in the data that help you anticipate what's going to happen.
Overall
- "I enjoyed seeing the combination of the satellite products interacting with the radar and lightning products... it's a great planning tool."
- Need to come up with some pre-made default procedures for the experimental products... it's tough for forecasters to come in cold and learn how to load all of the products and then go into forecasting operations. The forecasters especially applauded the creation of the "ultimate-CI" procedure from last week and that should be saved.
- Create articulate presentations that forecasters can view beforehand rather than having "powerpoint death" on Mondays... this will also maximize the time forecasters have to look at the products.
- Would also be useful to create very short WES cases to send out beforehand that the forecasters can go through before they arrive.
- Forecaster would like to see the derived sounder products within the HWT AWIPS next year.
Thursday, May 26, 2011
Psuedo-GLM Products in the Mid-Atlantic
Forecasters conducted warning operations in the Sterling, VA and State College, PA CWAs, which allowed for analysis of the pseudo-GLM products (from the DCLMA). Although the earliest convection initiated along and just west of the Appalachian Mountains (out of range of the LMA), storms soon formed within range. Isolated storms initiated and developed rapidly ahead of the main line. The pseudo-GLM products detected IC flashes ~10 min prior to the first CG flashes in two of these storms. These storms continued to intensify and eventually merged into a line, further increasing the flash rates.
As the discrete cells merged into a line, flashes remained frequent, and the pseudo-GLM products helped confirm the strength of individual cells within the line. Greater flash rates also helped identify areas of new convection as they formed along the line.
Forecasters also observed that the pseudo-GLM swaths (i.e., 60 min sum of flashes) helped to illustrate persistent cells and identify the most intense portions of the line.
The above screen captures illustrate several four panel displays used to compare individual products in AWIPS. The pseudo-GLM products often were plotted alongside the 3-D Var updraft and vorticity tracks, as well as the multi-radar multi-sensor hail swaths and reflectivity at -10 C.
Scott Rudlosky
As the discrete cells merged into a line, flashes remained frequent, and the pseudo-GLM products helped confirm the strength of individual cells within the line. Greater flash rates also helped identify areas of new convection as they formed along the line.
Forecasters also observed that the pseudo-GLM swaths (i.e., 60 min sum of flashes) helped to illustrate persistent cells and identify the most intense portions of the line.
The above screen captures illustrate several four panel displays used to compare individual products in AWIPS. The pseudo-GLM products often were plotted alongside the 3-D Var updraft and vorticity tracks, as well as the multi-radar multi-sensor hail swaths and reflectivity at -10 C.
Scott Rudlosky
EWP forecaster debrief... 26 May
This afternoon we had an extensive debrief session with the EWP forecasters regarding the tornado outbreak from this past Tuesday (24 May). We asked them in detail what they saw for each of the products, and these are the responses/comments we received for the GOES-R products...
Convective Initiation
- We were seeing 10-15 minute lead times from the UAH CI product along the dryline prior to any echoes above 35 dBZ on radar. The UWCI was much more conservative and missed a few instances of CI, but it had less false alarms and similar lead times when it did trigger for CI.
- UAH CI did show some signals after initiation behind the dryline, but nothing really continued to grow. However, forecaster mentioned how this would be very useful in warning operations to help increase situational awareness for future development when you may be focusing primarily on the first storms.
- Forecaster mentioned how he was watching the UAH CI this morning over the SE and it was giving negative lead times and UWCI was not flagging anything at all. However, he did want to emphasize that on Tuesday GOES-E was in rapid-scan operations and was not this morning, so that could be why the lead times were so poor.
Pseudo-GLM
- Very useful as a situational awareness tool during warning ops... Forecasters saw rapid increases in the instantaneous flash rates prior to increases in reflectivity and other products such as the 3D-VAR updraft strength and various MRMS products.
- Forecaster mentioned that it would be nice to have a line graph display for this to help identify jumps better. (Kristin and I did mention that we have heard that forecasters would not like this in the past since it would remove them from the D2D during warning ops... forecaster responded with that you can do this as a percentage change product within the storm interrogator software within AWIPS which could mitigate this.)
- Forecasters found that the track product (that we currently use as a proxy for a jump graphic) was not very useful in detecting 'jumps' mainly because of the resolution of the product... the rapid changes could not be seen because they would generally overlap on the same pixel.
- There were moments that some data outages occurred within the OKLMA network that caused some false instances of 'jumps' and lack of signal. It was theorized that the sensors were becoming attenuated in heavy rain and not transmitting data since they are daisy-chained. Also, one tower was hit by a tornado and caused a large break in the chain, so the OKLMA is down until further notice, possibly throughout the remainder of the experiment.
Overshooting-tops / Thermal Couplet
- Not many were seen, but those that were tended to be near the center of the upper low.
- Those that were seen did coincide with instances of increases in reflectivity aloft.
- Usefulness within warning ops very minimal because of lack of detections.
Convective Initiation
- We were seeing 10-15 minute lead times from the UAH CI product along the dryline prior to any echoes above 35 dBZ on radar. The UWCI was much more conservative and missed a few instances of CI, but it had less false alarms and similar lead times when it did trigger for CI.
- UAH CI did show some signals after initiation behind the dryline, but nothing really continued to grow. However, forecaster mentioned how this would be very useful in warning operations to help increase situational awareness for future development when you may be focusing primarily on the first storms.
- Forecaster mentioned how he was watching the UAH CI this morning over the SE and it was giving negative lead times and UWCI was not flagging anything at all. However, he did want to emphasize that on Tuesday GOES-E was in rapid-scan operations and was not this morning, so that could be why the lead times were so poor.
Pseudo-GLM
- Very useful as a situational awareness tool during warning ops... Forecasters saw rapid increases in the instantaneous flash rates prior to increases in reflectivity and other products such as the 3D-VAR updraft strength and various MRMS products.
- Forecaster mentioned that it would be nice to have a line graph display for this to help identify jumps better. (Kristin and I did mention that we have heard that forecasters would not like this in the past since it would remove them from the D2D during warning ops... forecaster responded with that you can do this as a percentage change product within the storm interrogator software within AWIPS which could mitigate this.)
- Forecasters found that the track product (that we currently use as a proxy for a jump graphic) was not very useful in detecting 'jumps' mainly because of the resolution of the product... the rapid changes could not be seen because they would generally overlap on the same pixel.
- There were moments that some data outages occurred within the OKLMA network that caused some false instances of 'jumps' and lack of signal. It was theorized that the sensors were becoming attenuated in heavy rain and not transmitting data since they are daisy-chained. Also, one tower was hit by a tornado and caused a large break in the chain, so the OKLMA is down until further notice, possibly throughout the remainder of the experiment.
Overshooting-tops / Thermal Couplet
- Not many were seen, but those that were tended to be near the center of the upper low.
- Those that were seen did coincide with instances of increases in reflectivity aloft.
- Usefulness within warning ops very minimal because of lack of detections.
Pseudo-GLM Perspective on Oklahoma Storms
This week started with two very active days within the OUN CWA which allowed EWP forecasters to incorporate pseudo-GLM products into their warning operations. Despite the dense radar coverage, forecasters used the total lightning products and provided some interesting insights.
Day One – Monday 23 May
Two storms developed in Northwest Oklahoma and exhibited very different lightning and radar signatures. The northern storm formed in Major County, exhibited very large IC flash rates, and produced large hail. Conversely, the flash densities were much smaller in the southern storm which produced a brief tornado. This observation illustrated the variability between two storms that occurred in a similar environment and emphasizes the importance of continued research on the relationships between lightning and radar within individual storms.
The greatest pseudo-GLM densities (> 30 flashes/ km/min) accompanied a large storm cluster which followed the merger of two strong storms. The 3D-Var products indicated a strong updraft throughout the length of this storm cluster which helps explain the high flash rates.
Day Two – Tuesday 24 May
The high risk forecast and model-derived products all indicated a very active day was in store. The CI products identified the initial convection 15-20 minutes prior to the first pseudo-GLM signatures. Flash rates increased rapidly in the earliest convection, and the first tornadic storm occurred as two isolated storms merged near Weatherford, OK. Flash rates spiked as the two storms merged, coincident with an increase in mid-level rotation. These combined observations increased forecaster confidence as they issued the first tornado warning of the day.
The EWP forecasters observed that the greatest pseudo-GLM flash densities consistently tracked ahead of the main updraft and actually helped to identify changes in storm motion. On several occasions the pseudo-GLM densities also indicated that the main center of rotation was shifting prior to the identification of new rotation tracks by the multi-radar multi-sensor algorithms.
Although lightning jumps preceded many of the tornados, forecasters commented that they would have liked to examine time trends for individual storms. This has been a common theme during previous spring experiments, and was not fully accounted for by plotting swaths of the pseudo-GLM products.
- Scott Rudlosky
Day One – Monday 23 May
Two storms developed in Northwest Oklahoma and exhibited very different lightning and radar signatures. The northern storm formed in Major County, exhibited very large IC flash rates, and produced large hail. Conversely, the flash densities were much smaller in the southern storm which produced a brief tornado. This observation illustrated the variability between two storms that occurred in a similar environment and emphasizes the importance of continued research on the relationships between lightning and radar within individual storms.
The greatest pseudo-GLM densities (> 30 flashes/ km/min) accompanied a large storm cluster which followed the merger of two strong storms. The 3D-Var products indicated a strong updraft throughout the length of this storm cluster which helps explain the high flash rates.
Day Two – Tuesday 24 May
The high risk forecast and model-derived products all indicated a very active day was in store. The CI products identified the initial convection 15-20 minutes prior to the first pseudo-GLM signatures. Flash rates increased rapidly in the earliest convection, and the first tornadic storm occurred as two isolated storms merged near Weatherford, OK. Flash rates spiked as the two storms merged, coincident with an increase in mid-level rotation. These combined observations increased forecaster confidence as they issued the first tornado warning of the day.
The EWP forecasters observed that the greatest pseudo-GLM flash densities consistently tracked ahead of the main updraft and actually helped to identify changes in storm motion. On several occasions the pseudo-GLM densities also indicated that the main center of rotation was shifting prior to the identification of new rotation tracks by the multi-radar multi-sensor algorithms.
Although lightning jumps preceded many of the tornados, forecasters commented that they would have liked to examine time trends for individual storms. This has been a common theme during previous spring experiments, and was not fully accounted for by plotting swaths of the pseudo-GLM products.
- Scott Rudlosky
Monday, May 23, 2011
Ultimate CI
Visiting scientists and NWS forecasters visiting the EWP this week have begun looking at real-time data with the promise of some exciting weather over OK this evening. We are currently examining the SATCAST and UWCI products in combination with the multi-radar multi-sensor (MRMS) and PGLM products to anticipation convective initiation. The participants have worked together to develop what has been so lovingly called the "ultimate CI" 4-panel display within AWIPS. The 4-panel (shown above) includes the following products that are linked to the nowcast and detection of CI... Starting from top left and moving anti-cyclonic (clockwise) we have the visible with SATCAST, visible with UWCI, visible with MRMS reflectivity at -10 C, and finally visible with PGLM and NLDN lightning detections. The 4-panel has been saved as a procedure that forecasters can now load very quickly within their AWIPS D2D workstations throughout the rest of the week. Future visitors will have this available as well. This helps demonstrate the ability to combine these unique datasets from multiple sensors into one effective decision support tool.
Friday, May 20, 2011
EWP end of week debrief... 20 May
Today we spent a couple hours soliciting the forecasters for feedback on all of the products that they worked with this week within the EWP. Given the opportunity, I asked the forecasters some follow-up questions based on some observations this week and from yesterday's event, as well as some of their survey responses. Below are the comments from the discussion...
Convective Initiation
- The CIMSS product had pretty good lead time before we actually started seeing lightning of about 45 minutes to 1 hour, only about 15 minute lead time over 35 dBZ echo.
- Later in the events everything became cloud masked.
- Mostly masked with the CIMSS stuff, but UAH was not and we were expecting CI behind the initial line, but nothing went and there were no CI nowcasts made, so that was very good that we weren't getting false alarms.
- There were times when they would have 30 minute lead-times on radar echos, and other times there were no lead-times during the same event.
- I would like to spend some time looking at those products in more my type of environments, like weak shear.
- A probabilistic approach might be more useful than a simple yes/no output. I like the idea of having pre-CI through CI ongoing information.
- "I tended to look at the UAH one more because it was giving me more detections."
- "I found having the masking overlaid was very important... there were times where the CIMSS wasn't showing something but the UAH was and it helped me get an idea of why."
Overshooting-top / Thermal Couplet
- Later on in the evening we saw some detections, but earlier on we could see some enhanced-v and OT signatures in the imagery, but none were detected.
- If you had someone in operations during warning times that was just doing mesoanalysis and telling forecasters that a detection occurred would be very useful... I get too involved with interrogating radar data during warnings.
- Rapid-scan, high resolution satellite data would definitely make this more useful.
- Would like to see an overshooting top collapse product... maybe an alert.
- Only had a chance to look at the icon detections.
Nearcast
- Saw a moisture tongue coming through, but nothing happened.
- Focused primarily on theta-e product, trying to figure out best way to use that... the challenge the day before was that nothing happened, so it's hard to find the values that are more significant... didn't notice any strong signals yesterday, so I didn't really use it.
- Were not able to get the multiple levels in AWIPS... would like to see those.
- "My initial thoughts were that this was no different than looking at the RUC theta-e product... but I do understand that it was nice to have it based on the observations."
- Would definitely like to see this in my home WFO.
Pseudo-GLM
- What could be really useful for forecasters is some training on total lightning activity and how it relates to what's going on within storms.
- Specific numbers for what an intense flash rate is would be helpful.
- We're fairly comfortable with looking at CG activity and what that means, but an IC/CG ratio product would be useful.
- You can get a sense for the trends, especially when significant, but there's a lot of complexity when looking at the entire storm with some areas decreasing and increasing rapidly within the same cell. Maybe if you could interrogate the storm and get a graph of the total lightning activity.
- We have a lot of users like golf courses and parks that we may not be paying attention to, especially for lightning safety in stratoform rain regions where people may think that it's just light rain. When I'm in warning operations, I get engaged in the base radar data and pay less attention to everything else. This may help a lot in those situations.
Overall
- If we had it set up that one person was in charge of the warnings and looking at the radar data, then the other person could focused on a couple of the experimental products if you're working in pairs at the same desk. If the other desk could do the same thing with a couple of the other experimental products, we might be able to get more useful information on everything.
- "Maybe if we had a couple hours each day to just focus on one product, so all of the fields in the product could be examined. I know I set up a real quick procedure on the first day and only got to look at a couple of the fields and felt like I left the rest behind."
- "I'm wondering if a 2-week period would be better for each forecaster... the first week could be used to get comfortable with all of the products and then the second week we could really get into the products in warning operations." (Difficult to get a forecaster away from their office for 2-weeks... especially in May.)
- If forecasters had a week or two to go through articulate presentations prior to arriving that would help us hit the ground running on the first day and avoid powerpoint death. Make it a prerequisite then have a short discussion with the PIs on what they want to focus on during the first day and go into short DRTs for each product.
Convective Initiation
- The CIMSS product had pretty good lead time before we actually started seeing lightning of about 45 minutes to 1 hour, only about 15 minute lead time over 35 dBZ echo.
- Later in the events everything became cloud masked.
- Mostly masked with the CIMSS stuff, but UAH was not and we were expecting CI behind the initial line, but nothing went and there were no CI nowcasts made, so that was very good that we weren't getting false alarms.
- There were times when they would have 30 minute lead-times on radar echos, and other times there were no lead-times during the same event.
- I would like to spend some time looking at those products in more my type of environments, like weak shear.
- A probabilistic approach might be more useful than a simple yes/no output. I like the idea of having pre-CI through CI ongoing information.
- "I tended to look at the UAH one more because it was giving me more detections."
- "I found having the masking overlaid was very important... there were times where the CIMSS wasn't showing something but the UAH was and it helped me get an idea of why."
Overshooting-top / Thermal Couplet
- Later on in the evening we saw some detections, but earlier on we could see some enhanced-v and OT signatures in the imagery, but none were detected.
- If you had someone in operations during warning times that was just doing mesoanalysis and telling forecasters that a detection occurred would be very useful... I get too involved with interrogating radar data during warnings.
- Rapid-scan, high resolution satellite data would definitely make this more useful.
- Would like to see an overshooting top collapse product... maybe an alert.
- Only had a chance to look at the icon detections.
Nearcast
- Saw a moisture tongue coming through, but nothing happened.
- Focused primarily on theta-e product, trying to figure out best way to use that... the challenge the day before was that nothing happened, so it's hard to find the values that are more significant... didn't notice any strong signals yesterday, so I didn't really use it.
- Were not able to get the multiple levels in AWIPS... would like to see those.
- "My initial thoughts were that this was no different than looking at the RUC theta-e product... but I do understand that it was nice to have it based on the observations."
- Would definitely like to see this in my home WFO.
Pseudo-GLM
- What could be really useful for forecasters is some training on total lightning activity and how it relates to what's going on within storms.
- Specific numbers for what an intense flash rate is would be helpful.
- We're fairly comfortable with looking at CG activity and what that means, but an IC/CG ratio product would be useful.
- You can get a sense for the trends, especially when significant, but there's a lot of complexity when looking at the entire storm with some areas decreasing and increasing rapidly within the same cell. Maybe if you could interrogate the storm and get a graph of the total lightning activity.
- We have a lot of users like golf courses and parks that we may not be paying attention to, especially for lightning safety in stratoform rain regions where people may think that it's just light rain. When I'm in warning operations, I get engaged in the base radar data and pay less attention to everything else. This may help a lot in those situations.
Overall
- If we had it set up that one person was in charge of the warnings and looking at the radar data, then the other person could focused on a couple of the experimental products if you're working in pairs at the same desk. If the other desk could do the same thing with a couple of the other experimental products, we might be able to get more useful information on everything.
- "Maybe if we had a couple hours each day to just focus on one product, so all of the fields in the product could be examined. I know I set up a real quick procedure on the first day and only got to look at a couple of the fields and felt like I left the rest behind."
- "I'm wondering if a 2-week period would be better for each forecaster... the first week could be used to get comfortable with all of the products and then the second week we could really get into the products in warning operations." (Difficult to get a forecaster away from their office for 2-weeks... especially in May.)
- If forecasters had a week or two to go through articulate presentations prior to arriving that would help us hit the ground running on the first day and avoid powerpoint death. Make it a prerequisite then have a short discussion with the PIs on what they want to focus on during the first day and go into short DRTs for each product.
Thursday, May 19, 2011
pGLM realtime comparison with MESH and 3D-Var Updraft
Repost from EWP blog...
With warning operations already underway for western Oklahoma, forecasters are deep into their storm analysis.
One of the more interesting features they have been picking up on is the consistent signals between the pGLM lightning trends and values from the MESH (Maximum Expected Size of Hail) algorithm as well as the 3D-Var derived updraft fields.
This was well illustrated by the storm north of Elk City moving from Beckham to Roger Mills county. At approximately the same time ~1900-1915 UTC, the lightning rate increased from 5 to 15 flashes per min (per pGLM grid box, not per storm) as MESH ramped up and updraft increased within the 3D-Var product. Shortly after this increase, both the pGLM and MESH values decreased with this storm (the 3D-Var updraft values also showed this, but with a bit of a time lag).
pGLM flash density and MESH values at 1910 UTC on 19 May 2011
Also of note, prior to losing NLDN data, with the storms seemed to be producing relatively little CG lightning. In this case, the pGLM data was definitely giving a better view of the electrical activity and storm intensity. (1 to 1.75 in hail has already been reported across West and SW Oklahoma).
-K. Kuhlman (pGLM scientist, week 2)
With warning operations already underway for western Oklahoma, forecasters are deep into their storm analysis.
One of the more interesting features they have been picking up on is the consistent signals between the pGLM lightning trends and values from the MESH (Maximum Expected Size of Hail) algorithm as well as the 3D-Var derived updraft fields.
This was well illustrated by the storm north of Elk City moving from Beckham to Roger Mills county. At approximately the same time ~1900-1915 UTC, the lightning rate increased from 5 to 15 flashes per min (per pGLM grid box, not per storm) as MESH ramped up and updraft increased within the 3D-Var product. Shortly after this increase, both the pGLM and MESH values decreased with this storm (the 3D-Var updraft values also showed this, but with a bit of a time lag).
Also of note, prior to losing NLDN data, with the storms seemed to be producing relatively little CG lightning. In this case, the pGLM data was definitely giving a better view of the electrical activity and storm intensity. (1 to 1.75 in hail has already been reported across West and SW Oklahoma).
-K. Kuhlman (pGLM scientist, week 2)
PGLM products in AWIPS
Forecasters are now examining the PGLM products within their AWIPS workstations during warning operations with several storms over SW OK. The forecasters have created a 4-panel display that contains the 3 current PGLM products we are providing within the EWP, as well as the traditional radar reflectivity and NLDN detections (see image above). The forecasters currently have access to an instantaneous flash extent density (top right corner), a 60 minute sum (bottom left corner) and a 60 minute max track (bottom right corner). We are also working on providing the forecasters with a flash initiation density product, which will hopefully be available next week.
Monday, May 16, 2011
Total lightning preceeding the first cloud-to-ground strike (Repost)
As we watched the storms move through central Oklahoma today a small, isolated cell developed over Lawton, Oklahoma. This storm conveniently gave us the opportunity to show the effectiveness of total lightning observations in helping gain lead-time ahead of the first cloud-to-ground lightning strike. This small cell turned out to be even more interesting as the PGLM observations gave a 29 minute lead-time over the first cloud-to-ground strike. This was pretty remarkable as the lead time is usually on the order of 5-10 minutes. Below are three images showing the event.
FIGURE 1: A four panel display in AWIPS from 2055 UTC on 11 May 2011. Going clockwise from the upper-left is the radar reflectivity, PGLM flash extent density, PGLM maximum flash density, and NLDN cloud-to-ground lightning strike observations. A single flash just southwest of Lawton (KLAW) can be seen in the PGLM flash extent density and no cloud-ground strikes are observed with the Lawton cell.
FIGURE 2: The same as FIGURE 1, except for the time is 2100 UTC. The PGLM flash extent shows two flashes and the radar reflectivity has strengthened.
FIGURE 3: The same as FIGURE 1, except for the time is 2124 UTC. The radar reflectivity has increased more and the PGLM flash extent density shows several flashes. The NLDN cloud-to-ground lightning observations finally shows a single, negative cloud-to-ground strike just to the northeast of Lawton, Oklahoma. This PGLM gave a tremendous 29 minute lead time on this first strike.
FIGURE 1: A four panel display in AWIPS from 2055 UTC on 11 May 2011. Going clockwise from the upper-left is the radar reflectivity, PGLM flash extent density, PGLM maximum flash density, and NLDN cloud-to-ground lightning strike observations. A single flash just southwest of Lawton (KLAW) can be seen in the PGLM flash extent density and no cloud-ground strikes are observed with the Lawton cell.
FIGURE 2: The same as FIGURE 1, except for the time is 2100 UTC. The PGLM flash extent shows two flashes and the radar reflectivity has strengthened.
FIGURE 3: The same as FIGURE 1, except for the time is 2124 UTC. The radar reflectivity has increased more and the PGLM flash extent density shows several flashes. The NLDN cloud-to-ground lightning observations finally shows a single, negative cloud-to-ground strike just to the northeast of Lawton, Oklahoma. This PGLM gave a tremendous 29 minute lead time on this first strike.
Wednesday, May 11, 2011
First Total Lightning Ops Day
Wednesday is shaping up to be the first ops day to use total lightning data for the Spring Program this year. The main area of focus will be in central Oklahoma using observations from the Oklahoma Lightning Mapping Array.
This year, there will be two additional products added to the lightning product list. In 2010, NASA's Short-term Prediction Research and Transition (SPoRT) program developed the pseudo Geostationary Lightning Mapper (PGLM) product. This was a simple algorithm that could be applied to any ground-based total lightning network. While it is not the official Algorithm Working Group proxy product, it was designed to be used at the Spring Program until the proxy is available. The PGLM is simply a tool to train forecasters about total lightning and the Geostationary Lightning Mapper, and a way to work with forecasters to determine the best way to use the 8 km resolution data. Addtionally, this product gives end users the opportunity to discuss new ways to better visualize these data.
Based on feedback from the 2010 Spring Program and SPoRT's efforts to enhance the visualizations, two new PGLM products have been introduced for 2011. These are the flash initiation density and the maximum flash density (MFD) products. Figure 1 shows the original PGLM (1 minute data, bright color) overlaid with the MFD (60 minute history, faded color). The MFD shows the largest PGLM value for each grid box for either 60 or 120 minutes. It is effective to show a basic trend in lightning activity over time. In Figure 1 below, taken at 1446 UTC on 11 May 2011, the MFD shows a large amount of lightning activity from storms as they entered western Oklahoma. However, the PGLM data show that these storms have greatly diminished in lightning activity. Figure 2 shows the corresponding radar reflectivity from KFDR.
FIGURE 1: The 60 minute maximum flash density (faded color) and the 1 minute pseudo geostationary lightning mapper flash extent density (bright color) taken at 1446 UTC. Note how the PGLM shows that the lightning activity has greatly diminished, both in magnitude and extent.
This year, there will be two additional products added to the lightning product list. In 2010, NASA's Short-term Prediction Research and Transition (SPoRT) program developed the pseudo Geostationary Lightning Mapper (PGLM) product. This was a simple algorithm that could be applied to any ground-based total lightning network. While it is not the official Algorithm Working Group proxy product, it was designed to be used at the Spring Program until the proxy is available. The PGLM is simply a tool to train forecasters about total lightning and the Geostationary Lightning Mapper, and a way to work with forecasters to determine the best way to use the 8 km resolution data. Addtionally, this product gives end users the opportunity to discuss new ways to better visualize these data.
Based on feedback from the 2010 Spring Program and SPoRT's efforts to enhance the visualizations, two new PGLM products have been introduced for 2011. These are the flash initiation density and the maximum flash density (MFD) products. Figure 1 shows the original PGLM (1 minute data, bright color) overlaid with the MFD (60 minute history, faded color). The MFD shows the largest PGLM value for each grid box for either 60 or 120 minutes. It is effective to show a basic trend in lightning activity over time. In Figure 1 below, taken at 1446 UTC on 11 May 2011, the MFD shows a large amount of lightning activity from storms as they entered western Oklahoma. However, the PGLM data show that these storms have greatly diminished in lightning activity. Figure 2 shows the corresponding radar reflectivity from KFDR.
FIGURE 1: The 60 minute maximum flash density (faded color) and the 1 minute pseudo geostationary lightning mapper flash extent density (bright color) taken at 1446 UTC. Note how the PGLM shows that the lightning activity has greatly diminished, both in magnitude and extent.
Friday, June 18, 2010
EWP weekly debrief
Today is the end of this year's Spring Experiment, and what a fitting end. Yesterday was our busiest day in the EWP over ND/MN/IA. As of the time of this entry there were 65 tornadoes reported over the area associated with the event. It was indeed a big day, and luckily there were no technical issues during the IOP. Unfortunately, due to the rapid developing nature of this event the GOES-R products were used only for a short time before it was essential to move into radar operations for warning purposes. The forecasters were inundated with issuing tornado warning pretty much in a consistent line from Canada down into IA. We were able to get some feedback and since this is the weekly debrief I was able to ask the forecasters in more detail, based on my observations this week as well as their survey responses. Here is a breakdown of what we discussed...
UWCI
I asked about the lead times from the surveys... 15-30 mins the general consensus?
"Hard to be sure because we were arriving at the HWT after convection was developing."
"Getting in there around noon would get more accurate results."
"The case event was already initiated when I got there."
"Struggling giving up screen space during severe weather" (from survey)... is there a display you think would help?
"Having an additional head would help. We were only provided with two screens so it changed our strategy."
"Would be useful for the mesoanalyst position at the WFO."
"4-panel devoted to those products works well."
I asked the forecasters if they were ok with more signals if that meant giving up some FAR...
"I would like earlier signals, like a probability signal... which part of my CWA is going to have the best chance... Some kind of signal before there's aggitated clouds would be helpful."
I asked the forecasters whether they preferred the CI or the cloud-top cooling...
"I used them both... kind of liked them both simultaneously."
"It was hard because it seemed it was 50/50 on detecting things so I lost a lot of confidence in using the product, but I did like the cloud-top cooling a little better because it seemed to do better."
I asked the forecasters if they preferred the accumulated of instantaneous fields...
"I stuck with the instantaneous for the most part, I don't think I even looked at the accumulated to be honest."
"I tended to look at the instantaneous."
Would you see a benefit in having a cloud-top cooling track?
"Yes... an overshooting top track would be very useful as well."
OTTC
Detections or magnitudes more useful?
"I looked at the detections only."
Did you see any correlations between OT detections and features developing on radar?
"Reflectivity was increasing above certain (height) levels at that time."
How often did the product correctly detect OTs that you could see on VIS/IR?
"Kinda 50/50."
"For a warning operator, I don't see this product adding much value to an on-going event..." (from survey) Why is that? Lack of detection, timeliness, applicability of product?
"Radar was more important... mix between timeliness and applicability."
"Get a good a western example case where you don't have radar."
"Maybe knock out some radars in a WES case."
PGLM
"It's an acquired taste, working with lightning data. I think it's a fundamental component in the decision making process trying to determine what's going on with the updraft... it's an interesting way of looking at it."
"With supercells I don't see any added benefit, unless it flared up right before an RFD developed... but I would have to see a lot of cases before I could determine that."
"Would be of a lot of value in low top events."
"Would be nice to see it in a non-supercell case event, like winter events."
"In terms of just lightning forecasting... I think the GLM stuff you were showing would be very useful in that area."
OVERALL / TRAINING
Overall feelings following the week...
"I'm 50/50... I'm not leaving here warm and fuzzy if that's what you're asking."
"When I came in I was very excited to have the convective initiation... I don't come out feeling as confident as I did and as excited as I did when I came in."
"The word convective initiation tool sounds awesome, maybe I went into it with high expectations as maybe seeing a tool with some probabilistic information."
How confident were you with the products following the training?
"The products were easy to understand so I was confident in using them."
What changes/additions would you like to see with the training?
Cases in the west re-iterated.
"The training itself was fine... it just seemed that it didn't perform as well as we would like to see."
I asked if the forecasters would like some sort of alert for the GOES-R products (UWCI, OTTC), so they would know when a detection was occurring, or if that would be more annoying than helpful...
"An initial alert would be nice... a continuous one would be overload."
"That would vary forecaster to forecaster."
Re-iterated the need for wind-based warning products.
"When I got really busy, I went back to the things I was used to using. I was just falling back on my normal routine."
"Would be nice on the first day to have a sort of hand-holding process to get used to the products."
"Maybe already have a base set of procedures so we don't have to spend 30 minutes setting everything up... especially on the first day."
Need cases where radar was out or nocturnal events over poor radar coverage.
UWCI
I asked about the lead times from the surveys... 15-30 mins the general consensus?
"Hard to be sure because we were arriving at the HWT after convection was developing."
"Getting in there around noon would get more accurate results."
"The case event was already initiated when I got there."
"Struggling giving up screen space during severe weather" (from survey)... is there a display you think would help?
"Having an additional head would help. We were only provided with two screens so it changed our strategy."
"Would be useful for the mesoanalyst position at the WFO."
"4-panel devoted to those products works well."
I asked the forecasters if they were ok with more signals if that meant giving up some FAR...
"I would like earlier signals, like a probability signal... which part of my CWA is going to have the best chance... Some kind of signal before there's aggitated clouds would be helpful."
I asked the forecasters whether they preferred the CI or the cloud-top cooling...
"I used them both... kind of liked them both simultaneously."
"It was hard because it seemed it was 50/50 on detecting things so I lost a lot of confidence in using the product, but I did like the cloud-top cooling a little better because it seemed to do better."
I asked the forecasters if they preferred the accumulated of instantaneous fields...
"I stuck with the instantaneous for the most part, I don't think I even looked at the accumulated to be honest."
"I tended to look at the instantaneous."
Would you see a benefit in having a cloud-top cooling track?
"Yes... an overshooting top track would be very useful as well."
OTTC
Detections or magnitudes more useful?
"I looked at the detections only."
Did you see any correlations between OT detections and features developing on radar?
"Reflectivity was increasing above certain (height) levels at that time."
How often did the product correctly detect OTs that you could see on VIS/IR?
"Kinda 50/50."
"For a warning operator, I don't see this product adding much value to an on-going event..." (from survey) Why is that? Lack of detection, timeliness, applicability of product?
"Radar was more important... mix between timeliness and applicability."
"Get a good a western example case where you don't have radar."
"Maybe knock out some radars in a WES case."
PGLM
"It's an acquired taste, working with lightning data. I think it's a fundamental component in the decision making process trying to determine what's going on with the updraft... it's an interesting way of looking at it."
"With supercells I don't see any added benefit, unless it flared up right before an RFD developed... but I would have to see a lot of cases before I could determine that."
"Would be of a lot of value in low top events."
"Would be nice to see it in a non-supercell case event, like winter events."
"In terms of just lightning forecasting... I think the GLM stuff you were showing would be very useful in that area."
OVERALL / TRAINING
Overall feelings following the week...
"I'm 50/50... I'm not leaving here warm and fuzzy if that's what you're asking."
"When I came in I was very excited to have the convective initiation... I don't come out feeling as confident as I did and as excited as I did when I came in."
"The word convective initiation tool sounds awesome, maybe I went into it with high expectations as maybe seeing a tool with some probabilistic information."
How confident were you with the products following the training?
"The products were easy to understand so I was confident in using them."
What changes/additions would you like to see with the training?
Cases in the west re-iterated.
"The training itself was fine... it just seemed that it didn't perform as well as we would like to see."
I asked if the forecasters would like some sort of alert for the GOES-R products (UWCI, OTTC), so they would know when a detection was occurring, or if that would be more annoying than helpful...
"An initial alert would be nice... a continuous one would be overload."
"That would vary forecaster to forecaster."
Re-iterated the need for wind-based warning products.
"When I got really busy, I went back to the things I was used to using. I was just falling back on my normal routine."
"Would be nice on the first day to have a sort of hand-holding process to get used to the products."
"Maybe already have a base set of procedures so we don't have to spend 30 minutes setting everything up... especially on the first day."
Need cases where radar was out or nocturnal events over poor radar coverage.
Thursday, June 17, 2010
EWP daily briefing... 6/17/2010
At the beginning of the briefing we discussed yesterday real-time IOP event over the Sterling, VA WFO CWA. We had the ability to use the PGLM output from the DCLMA for this event. Most of the warnings issued were for severe wind threats and were fairly marginal. One of the forecasters mentioned that he focused on the PGLM products because of the marginal nature of the event to try and pick out regions of greater importance since the radar and MRMS products were showing similar features for most of the convection around the area. However, due to the marginal nature of the event, no strong conclusions were drawn as to the usefulness of a lot of the experimental data. One of the forecasters brought up the idea of creating regional versions of some of the products to try and draw more information from them. This may eventually be useful for products like the CI and cloud-top cooling products since we have seen some regional dependence on the product performance (ie - diagnostic over SE US)
We also discussed the performance of the UWCI over the same area. The forecasters reiterated the lack of detection over WV/VA border from yesterday's blog post. We believe that this was due to some microphysical issues being presented in the cloud typing product that were masking out the CI signals. We mentioned that we had wished we had moved to SD sooner, which is where we ended up for the remainder of yesterday's IOP. There were a lot of signals over that area (see image above), but we were unsure as to the timing of them since we were not watching in real time. This would be a good case to look at in the future. Also, notice the lack of signals over the Sterling and State College WFO areas where we focused at the beginning of the day. Jordan Gerth discussed with the forecasters about the idea of providing a cloud-top cooling rate 'image' with no filtering, which would allow for the forecasters to see all areas of cooling/warming regardless of cloud motion or other effects that are currently removed. This would allow the forecasters decide for themselves what are false signals and may be particularly useful for determining the life cycle of MCS's and weakening supercell storms.
24-hour overshooting top (left) and thermal couplet (right) detections for 16 June 2010.
We examined the overshooting top and thermal couplet detections (see images above) and saw that both the overshooting top and thermal couplet detections did correlate well to the location of the severe weather in this case, especially over SD. However, when these were seen during the real-time IOP, it was already obvious that severe weather was occurring based on reports being received and the standard radar data. The overshooting top detections that continue further east, as well as the blob of CI nowcasts east of the tornadic storm were questioned by the forecasters since they occurred after the IOP ended and they were not sure how legitimate they were. We did look back very quickly to see what happened and it seemed as though a MCS developed later on associated with many additional warnings and it would have been nice to see the performance of the products in that instance. Again, this would be a good case to look at in the future. We will attempt to archive the data, but it may be difficult since we do not yet have dedicated disk space to do so.
The plan for today is to operate over MN and IA. This is our last chance for real-time IOPs and it looks like it should be a good one for GOES-R with the lack of cirrus in the area... assuming we get started soon enough.
Wednesday, June 16, 2010
EWP real-time IOP CI feedback
Today's IOP focused over the DCLMA domain to get some real-time PGLM experience. The forecasters broke up into two groups and localized over the Sterling, VA and State College, PA WFOs. The Sterling WFO group have been issuing severe thunderstorm warnings based on PGLM and MRMS products over the past couple hours. I was sitting with the State College WFO group as they were focusing on the UWCI products, watching for convective initiation over their area. One of the forecasters had multiple GOES-R Proving Ground products (UWCI, cloud-top cooling, overshooting top, and thermal couplet) into a 4-panel display and mentioned to me that this display strategy would be extremely useful as a situational awareness tool for monitoring satellite convective information.
GOES-13 IR imagery for 1832 (top left), 1845 (top right), 1902 (bottom left) and 1915 UTC (bottom right) on 16 June 2010. Area of interest noted by green circle.
We noticed an area of obvious convective development that was not detected by the UWCI product on the WV/VA border at 1915 UTC and the forecaster asked me to explain why no CI nowcast was made. Looking at the IR, you could see significant cooling occurring from 1832 and 1915 UTC (see above), but still no signals were seen. Jordan Gerth and I looked at the cloud typing output to see if we could draw any conclusions from that to determine what was going on (see below). Most of the area was covered by cloud types identified as 'water' or 'mixed phase'. However, there were a few spots of 'cirrus' classification over WV nearby where the CI nowcast should have been made. It seemed on visible and IR satellite that this may not have been the case, but this is hard to determine for sure. Jordan suggested that because there were these spots nearby that they may have been contaminating the spatial tests required by the algorithm to flag an area as filtered cloud-top cooling, and thus not allow for a CI nowcast to be made. This may be a fluke case where nothing can be done, but it may be useful to examine this in more detail to see if something can be improved.
UW-CIMSS Cloud typing product for 1832 (top left), 1845 (top right), 1902 (bottom left), and 1915 UTC (bottom right) on 16 June 2010. Area of interest noted by red circle.
GOES-13 IR imagery for 1832 (top left), 1845 (top right), 1902 (bottom left) and 1915 UTC (bottom right) on 16 June 2010. Area of interest noted by green circle.
We noticed an area of obvious convective development that was not detected by the UWCI product on the WV/VA border at 1915 UTC and the forecaster asked me to explain why no CI nowcast was made. Looking at the IR, you could see significant cooling occurring from 1832 and 1915 UTC (see above), but still no signals were seen. Jordan Gerth and I looked at the cloud typing output to see if we could draw any conclusions from that to determine what was going on (see below). Most of the area was covered by cloud types identified as 'water' or 'mixed phase'. However, there were a few spots of 'cirrus' classification over WV nearby where the CI nowcast should have been made. It seemed on visible and IR satellite that this may not have been the case, but this is hard to determine for sure. Jordan suggested that because there were these spots nearby that they may have been contaminating the spatial tests required by the algorithm to flag an area as filtered cloud-top cooling, and thus not allow for a CI nowcast to be made. This may be a fluke case where nothing can be done, but it may be useful to examine this in more detail to see if something can be improved.
UW-CIMSS Cloud typing product for 1832 (top left), 1845 (top right), 1902 (bottom left), and 1915 UTC (bottom right) on 16 June 2010. Area of interest noted by red circle.
Tuesday, June 15, 2010
EWP daily briefing... 6/15/2010
During today's EWP briefing we discussed the previous day's flooding event over OKC from a PGLM perspective. Unfortunately the event unfolded in the morning hours when the EWP was not operating, so we were unable to view the data in real-time. Kristin Kuhlman presented the archived data and discussed with the forecasters what the PGLM showed during the event. She also overlaid the OKLMA flash contours to show how the PGLM relates to what was actually occurring (see above), which really helped the forecasters get a grasp over what the PGLM was showing them. They noted that the lightning seemed to be mainly focused with convection developing on the backside of the system and that this would help radar operators focus on which areas had continued development and represented an increased threat for flooding and severe weather in the future.
24-hour UWCI detections (top left), overshooting top detections (top right), thermal couplet dtetections (bottom left), and SPC severe reports (bottom right) from 14 June 2010
Jordan Gerth showed the UWCI and OTTC products over the past 24 hours in comparison to the severe reports from the same time period (see above). He pointed out the the UWCI had a lot of hits over the southeast with the diurnal convection that was not necessarily severe. He was unsure about how the UWCI performed with the the widespread swatch of wind reports through NC, but it is highly possible that the mass of UWCI signals in WV may be in initiation point for this convection... but we would need to do an in depth analysis of the event to determine this. Also, the numerous severe reports over southern IN seemed to have no UWCI detections associated with them. We suspected this was due to the presence of cirrus over the area. Jordan also noted the high density of overshooting top detections over OK with very few severe reports. He made sure to mention that the overshooting top detections are not necessarily associated with severe weather at the surface, as they are more of an indication of turbulence and lightning threats. There were only a few thermal couplet detections, which are highly linked to severe weather. The three located over TX seemed to be the best examples for this day. Jordan also did a quick introduction to the UW-CIMSS Nearcasting product for the EWP forecasters and showed a couple case examples in addition to the output for today to show areas of convective destabilizations associated with differential theta-e and precipitable water fields. Unfortunately we were unable to establish data flow for this product in time for this Spring Experiment, but we do plan on having it for future experiments.
The plan for the day is to once again start early and operate over the SPC moderate risk area in southern IL/IN to examine the GOES-R Proving Ground products prior to warning operations. With a relatively cirrus free sky, it should be a good event to demonstrate the UWCI. However, some storms are currently ongoing and are possibly severe, so we are hoping for some new development further south and west of the ongoing convection. The WFO's localized for the start of the IOP will be Indianapolis, IN and Louisville, KY.
Monday, June 14, 2010
Real-time PGLM operations
The forecasters are now engaged in a real-time IOP over Norman, OK and Lubbock, TX. Luckily the OKLMA became operational once again right before the dinner break so we are able to get the forecasters familiar with the PGLM product. The first two forecasters to look at the PGLM data had some interesting comments regarding the product's potential uses and performance. One of the forecasters mentioned how useful the product would be in the case of being overloaded with radar information. For instance, during weak cap, high instability days when storms cover the entire radar area a radar operator can get 'tunnel vision' on a couple storms they initially think are the most important and forget about the rest. She said that a GLM product would be very useful in getting you 'back to reality' when you get overwhelmed and help you identify the cells which are most important at that time. Also, the same forecaster mentioned how they would use this in situations when they are bordering on issuing a severe warning. When the radar information is ambiguous or unchanging, the GLM would help determine whether or not to issue the warning based on any dramatic increases seen in the number of total flashes in the cell.
In one case during the IOP we saw the first occurrence of flashes from the PGLM occurring with a growing cell near the center of the OKLMA network 40 minutes prior to the first CG. Flash rates reaching 25 flashes / 8 km / min occurred 25 minutes prior to the first CG for the same cell. She mentioned that this would be extremely helpful in determining whether the cell was actually a 'thunderstorm' and something to watch out for, stating that a lot of forecasters use the first occurrence of a CG to start thinking about the possibility of that cell ever becoming severe. This would provide a much heightened level of situational awareness, especially when storms can rapidly produce tornadoes, severe hail and/or winds with little warning.
In one case during the IOP we saw the first occurrence of flashes from the PGLM occurring with a growing cell near the center of the OKLMA network 40 minutes prior to the first CG. Flash rates reaching 25 flashes / 8 km / min occurred 25 minutes prior to the first CG for the same cell. She mentioned that this would be extremely helpful in determining whether the cell was actually a 'thunderstorm' and something to watch out for, stating that a lot of forecasters use the first occurrence of a CG to start thinking about the possibility of that cell ever becoming severe. This would provide a much heightened level of situational awareness, especially when storms can rapidly produce tornadoes, severe hail and/or winds with little warning.
EWP daily plan
Following the training sessions for the GOES-R UWCI, OTTC and PGLM products we had planned to move into an immediate IOP focusing over the Norman, OK WFO to get some exposure for the PGLM product with the chance of severe weather entering the area. Unfortunately as we were finishing the training we had heard that some of the OKLMA stations went down due to the heavy flooding occurring in central OK. Therefore, we decided that the current plan should be to move the domain towards the VORTEX-II domain south of Lubbock, TX following the MRMS training for some severe weather applications for the remainder of the evening.
Friday, June 11, 2010
EWP weekly debrief
Here is the breakdown from this week's EWP weekly debrief...
UWCI
This week was plagued by cirrus... can't remove it so we need to communicate well the limitations of the product. Forecasters were mentioning that they were constantly referring to the cloud type web page and suggested providing this into AWIPS. Will severely limit the applicability.
"If it's a good day to use it, the forecasters will use it... Most useful prior to development... right now things have to start developing before we issue products, this gives us some additional lead time."
Forecasters mentioned that the product would be useful in nighttime operations... possibly get more lead time... At night, stuff fires so quickly... perhaps providing a CI alarm in AWIPS would help situational awareness. Forecasters suggested providing a nighttime WES case for training. Lee is going to distribute web site and explain how to use it so they can look at it anytime.
Expressed interest in CI accumulated to follow CI signals through time in case they missed a scan.
Limitations in sensor scan time noted.
Forecasters mentioned the interest in providing more signals. they saw a lot of cases where CI was obvious but was not captured by the product. I asked if they were ok with the idea to sacrifice FAR for more detections...
"More times I expected to see something and didn't happened more often than not... not useful if things aren't showing where I expected to see it."
"Could you build different thresholds? Could you build one that was not so strict?"
"What about probabilistic detection? Then you can set your own threshold."
"Concerned about FAR getting too high because then it'll stop getting used."
There was a request for using additional bands... "You guys know the best bands to use... If you can get more information from other bands, go for it"
I asked if they saw the UWCI product being a precursor to lightning...
"Did not specifically check."
"I was more correlating the 35-40 dBZ"
During an event with a strong cap, the UWCI/CTC showed signals but no development occurred (or continued to occur)... perhaps provide a case of this in training.
From yesterday's IOP over Boulder, CO area... cell showed CI at 22:30 UTC... at 22:58 UTC a 30-40 dBZ occurred... showing 28 min lead time. Similar results were seen throughout the week.
A forecaster asked is testing on simulated satellite imagery planned? Yes, but currently the computation time is expensive so 5 min data would be rough.
Forecaster requested that it would be nice if the UWCI automatically loaded with satellite imagery in AWIPS.
OTTC
Forecasters mentioned they don't know what overshooting tops tell you... need more examples of this in training/literature.
Losing confidence by high threshold when you can see in visible... maybe a training issue... when you see a detection maybe it's more serious than a typical OT.
Combining with storm top divergence... "I think there's a lot of potential there."
Forecasters requested thermal couplet/overshoot detections in one product... hard to watch two different products... takes up a window in their D2D... "The more we can combine the better."
PGLM
Need to understand the importance of lightning "jumps"... show what would be significant... "What type of airmass dependence would we see with that?"
Need a rate of change product. Also, need to explain downward jumps... "What do we think is going on with the storm?"
Polarity information... needs to be mentioned that the ground based can be used in comparison.
Smoothing reducing peaks and faking a high res product.
Max-value track product would be useful... similar to rotation/hail track MRMS products.
"I think one of the problems with using lightning data in the WFO (currently) is that forecasters realize that it's (NLDN) such a small percentage of what's really going on."
"My guess is when the product becomes available it'll become a mainstream product that people are looking at all the time."
"Not necessarily going to be the main warning product, but it will be a good confirmation tool. If I had paid more attention and been more aware I could have issued my tornado warning one scan earlier." (24 May 2008 case event)
I asked if they noticed any lead time on CG from the PGLM... ~10 mins in general... canned case and real-time.
OVERALL/TRAINING
Training experience...
"Getting some simulations where the product does work out to field (WES cases) is important... hard to trust people with a Powerpoint. But be careful of putting out WES cases... 20 min articulate cases are fabulous... too long and we don't have time."
"Thankful for the canned case"
Asked forecasters how confident in the products they were after the training...
"With the UWCI I felt really good about, the other one (OTTC) was good too, I just probably don't experience it as much in operations"
"If you guys see something during real-time operations, don't hesitate to tell us something was there... don't hesitate to be the hands on instructor for the first couple days."
I asked what additional information they would like to see in the training...
"When you see a detection, provide a 'here's what it means' quicklook that we can refer to in operations."
Examples where it didn't work (cirrus, cap), and why are needed.
GOES-R products seem to be more useful before storm initiation.
Forecasters re-iterated need for object tracking and end to end multi-sensor tool... combine lightning, radar and satellite.
MRMS and GOES-R products are sparse grids... what could be done to improve your awareness that things are happening?
"Message or prompt to tell you when things are occurring."
"Some hesitation in alarms though... start to drown them out, especially when too many things trying to alert you."
"Number in lop left corner showing number of detections, like NLDN products, would be very useful."
"If there are a lot of false detections this would be hard."
Forecasters mentioned that you shouldn't be too worried about shipping the color curve information... forecasters are going to change it anyways.
"Glad you guys are here... good to have the interactions that we have and learn how these things work."
UWCI
This week was plagued by cirrus... can't remove it so we need to communicate well the limitations of the product. Forecasters were mentioning that they were constantly referring to the cloud type web page and suggested providing this into AWIPS. Will severely limit the applicability.
"If it's a good day to use it, the forecasters will use it... Most useful prior to development... right now things have to start developing before we issue products, this gives us some additional lead time."
Forecasters mentioned that the product would be useful in nighttime operations... possibly get more lead time... At night, stuff fires so quickly... perhaps providing a CI alarm in AWIPS would help situational awareness. Forecasters suggested providing a nighttime WES case for training. Lee is going to distribute web site and explain how to use it so they can look at it anytime.
Expressed interest in CI accumulated to follow CI signals through time in case they missed a scan.
Limitations in sensor scan time noted.
Forecasters mentioned the interest in providing more signals. they saw a lot of cases where CI was obvious but was not captured by the product. I asked if they were ok with the idea to sacrifice FAR for more detections...
"More times I expected to see something and didn't happened more often than not... not useful if things aren't showing where I expected to see it."
"Could you build different thresholds? Could you build one that was not so strict?"
"What about probabilistic detection? Then you can set your own threshold."
"Concerned about FAR getting too high because then it'll stop getting used."
There was a request for using additional bands... "You guys know the best bands to use... If you can get more information from other bands, go for it"
I asked if they saw the UWCI product being a precursor to lightning...
"Did not specifically check."
"I was more correlating the 35-40 dBZ"
During an event with a strong cap, the UWCI/CTC showed signals but no development occurred (or continued to occur)... perhaps provide a case of this in training.
From yesterday's IOP over Boulder, CO area... cell showed CI at 22:30 UTC... at 22:58 UTC a 30-40 dBZ occurred... showing 28 min lead time. Similar results were seen throughout the week.
A forecaster asked is testing on simulated satellite imagery planned? Yes, but currently the computation time is expensive so 5 min data would be rough.
Forecaster requested that it would be nice if the UWCI automatically loaded with satellite imagery in AWIPS.
OTTC
Forecasters mentioned they don't know what overshooting tops tell you... need more examples of this in training/literature.
Losing confidence by high threshold when you can see in visible... maybe a training issue... when you see a detection maybe it's more serious than a typical OT.
Combining with storm top divergence... "I think there's a lot of potential there."
Forecasters requested thermal couplet/overshoot detections in one product... hard to watch two different products... takes up a window in their D2D... "The more we can combine the better."
PGLM
Need to understand the importance of lightning "jumps"... show what would be significant... "What type of airmass dependence would we see with that?"
Need a rate of change product. Also, need to explain downward jumps... "What do we think is going on with the storm?"
Polarity information... needs to be mentioned that the ground based can be used in comparison.
Smoothing reducing peaks and faking a high res product.
Max-value track product would be useful... similar to rotation/hail track MRMS products.
"I think one of the problems with using lightning data in the WFO (currently) is that forecasters realize that it's (NLDN) such a small percentage of what's really going on."
"My guess is when the product becomes available it'll become a mainstream product that people are looking at all the time."
"Not necessarily going to be the main warning product, but it will be a good confirmation tool. If I had paid more attention and been more aware I could have issued my tornado warning one scan earlier." (24 May 2008 case event)
I asked if they noticed any lead time on CG from the PGLM... ~10 mins in general... canned case and real-time.
OVERALL/TRAINING
Training experience...
"Getting some simulations where the product does work out to field (WES cases) is important... hard to trust people with a Powerpoint. But be careful of putting out WES cases... 20 min articulate cases are fabulous... too long and we don't have time."
"Thankful for the canned case"
Asked forecasters how confident in the products they were after the training...
"With the UWCI I felt really good about, the other one (OTTC) was good too, I just probably don't experience it as much in operations"
"If you guys see something during real-time operations, don't hesitate to tell us something was there... don't hesitate to be the hands on instructor for the first couple days."
I asked what additional information they would like to see in the training...
"When you see a detection, provide a 'here's what it means' quicklook that we can refer to in operations."
Examples where it didn't work (cirrus, cap), and why are needed.
GOES-R products seem to be more useful before storm initiation.
Forecasters re-iterated need for object tracking and end to end multi-sensor tool... combine lightning, radar and satellite.
MRMS and GOES-R products are sparse grids... what could be done to improve your awareness that things are happening?
"Message or prompt to tell you when things are occurring."
"Some hesitation in alarms though... start to drown them out, especially when too many things trying to alert you."
"Number in lop left corner showing number of detections, like NLDN products, would be very useful."
"If there are a lot of false detections this would be hard."
Forecasters mentioned that you shouldn't be too worried about shipping the color curve information... forecasters are going to change it anyways.
"Glad you guys are here... good to have the interactions that we have and learn how these things work."
Subscribe to:
Posts (Atom)