Using GOES-R CI in the NW U.S.

Not expecting a gangbusters severe day. The only area of real risk is across ID/MT today. We are starting out in the Missoula CWA and I have been checking out the GOES-R CI product. There have been some weak cells already showing some modest CTC signals…that one in the upper right panel is around -10C/15 min. The GOES-R CI product in the upper left has shown plenty of weak CI signals and a few stronger ones. Of particular note are all the pink areas on the GOES-R CI product. Those are “snow contaminated” areas…particularly widespread for this time of year! I find it neat that one can use the GOES-R CI in concert with the visible image to discern the real signals from the snowy noise. Continuing to wait for interesting storms.

CL

051313 2000 UTC CI (top left), CTC (top right), visible satellite (bottom left) and radar (bottom right)

Convective Initiation in West Texas

Operations started earlier today, in part to give the chance to use some of the GOES-R products, such as convective initiation, before cirrus contamination.  The two initial locations were Ft. Worth and San Angelo.  The blog post “CI/CTC Identifying Developing Convection in a Favorable Environment” (http://goesrhwt.blogspot.com/2013/05/cictc-identifying-developing-convection.html) summarizes the use of CI earlier in the day in the San Angelo county warning area.

By mid-afternoon, one group shifted to the Lubbock county warning area to investigate the PGLM in that region.  The transfer to Lubbock occurred as storms were already firing, but we took a look back to see what had occurred previously.  

Flipping back we observed the GOES-R CI provide a probability of convection around 20 at 1930 UTC in northwestern Motley County (yellow arrow).

The GOES-R CI (upper left), IR (upper right) and visible satellite (lower left), and Lubbock, Texas radar reflectivity (lower right) at 1930 UTC.

The GOES-R CI remained at this level until 1945 UTC when an upper 70 value was observed at the junction of Motley, Floyd, and Briscoe Counties (yellow arrow).  The visible satellite imagery shows that the features are nearly stationary.

The GOES-R CI (upper left), IR (upper right) and visible satellite (lower left), and Lubbock, Texas radar reflectivity (lower right) at 1945 UTC.

By the next scan, the GOES-R CI had topped 90 for the probability of convection at 2002 UTC (yellow arrow).  Up to this point, the radar was showing now activity in this area.  Also take note of the GOES-R CI in Briscoe County (red arrow) showing moderate strength of signal values around the county.

The GOES-R CI (upper left), IR (upper right) and visible satellite (lower left), and Lubbock, Texas radar reflectivity (lower right) at 2002 UTC.

We then move ahead to 2022 UTC, where radar first observes reflectivities exceeding 35 dBZ and a developing cell can be seen in both the IR and visible imagery in Motley County (yellow arrow).  The GOES-R CI continues to trend upward in Briscoe County (red arrow, and there is no current radar observations of storms.

The GOES-R CI (upper left), IR (upper right) and visible satellite (lower left), and Lubbock, Texas radar reflectivity (lower right) at 2022 UTC.

The situation continues to be interesting by 2045 UTC.  The Motley County storm (yellow arrow) continues to slowly grow.  Also, in Briscoe County (red arrow), where the GOES-R CI was suggesting possible initiation, we are observing several cells in the county on radar, although none have exceeded 35 dBZ just yet.

The GOES-R CI (upper left), IR (upper right) and visible satellite (lower left), and Lubbock, Texas radar reflectivity (lower right) at 2045 UTC.

Finally, at 2115 UTC, the radar signature for the storms in Motley and Briscoe Counties is well defined.  Note that the GOES-R CI stops tracking mature cells.

The GOES-R CI (upper left), IR (upper right) and visible satellite (lower left), and Lubbock, Texas radar reflectivity (lower right) at 2115 UTC.

The GOES-R CI provided the first indication of a potential cell in Motley County at 1930 UTC, giving it a 50 minute lead time.  Even with waiting for a stronger probability of convection, the GOES-R CI provided 35 minutes of lead time (signal of 70+), and 20 minutes (signal of 90+), respectively.  The GOES-R CI followed that with roughly 40 minutes of lead time for the Briscoe County storms.  Once the storms got rolling in this region, they became the focus of the PGLM total lightning blog post “Warning Issued with only PGLM Lightning Jump” (http://goesrhwt.blogspot.com/2013/05/warning-issued-with-only-pglm-lightning.html).

EWP end of week debrief... 10 June

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!

Some oberservations on my last day of observations

Today was an active day for observing CI across the country today. The initiation over the North East this morning had people scurrying to get AFD's, projected areas of interest, and survey's out in time to observe the storms. Hey, that is the point of testing experimental data, to see if it works.

For SATCAST, we picked up the first of the big convective storms moving across New York this morning with about 15-20 minutes of lead time. The UWCI product picked it up as well, just one satellite image later. Unfortunately, the storms started to fire, so time spent looking at CI products pretty much ended right then. Watching online using the research display, SATCAST looked to be doing pretty well picking out the new convection south of the line as it developed.

Watching again this afternoon over the dryline area over Texas, Oklahoma, and Kansas, SATCAST was putting up sporadic flags of CI in the late afternoon. In the early ones, the environment was not letting much grow, so the early flags didn't verify. SATCAST and UWCI put up flags simultaneously on the storm that became the large system that kept forecasters busy in the Wichita area. Before the forecasters switched their displays, SATCAST was flagging the convection that appeared about 20-30 minutes later in the southwest corner of Texas moving from LUB forecaster area to the OUN area.

Of course, the forecasters are now focused on tracking storms, putting out warnings, and using the other experimental products such as 3DVAR, the PGLM Lighting information, and the UW cloud top cooling rates, overshooting tops, and thermal couplet data to help them do it. This week's experience with the tools presented, how they were used, as well as interpreted, has provided both the forecasters and scientist with new ways to play with the data. SATCAST has performed well this week, maybe not perfect in some people's eyes, but well. It will be interesting to see where all of the tools presented go from here.

Integrating CI information into a single situational awareness tool

Discussions with forecasters throughout this year's Spring Experiment have raised an interesting topic regarding how to supply information without overwhelming forecasters during forecast and warning operations. In particular, forecasters have expressed interest in looking at all of the background interest fields from the UAH SATCAST product, which is currently being used as a proxy for the GOES-R CI product. The official GOES-R CI product will have 12 interest fields, all with a unique piece of information about the growth of a cumulus cloud object. As defined within the current GOES-R Algorithm Working Group (AWG) requirements, the CI product will only provide the forecasters with a binary yes/no output. Currently being provided within AWIPS/NAWIPS during the Spring Experiment, SATCAST has 6 interest fields that determine whether or not a cloud object is expected to convectively initiate within the next 0-2 hour time-frame. Forecasters have expressed some displeasure with only being provided a yes/no field to help them determine whether CI will occur. Some ideas have been offered that include providing a probabilistic CI nowcast, similar to what UWCI provides, or providing them with all of the CI interest fields individually in addition to the yes/no nowcast. Providing the forecasters with all of the interest fields and expecting them to look at them within their AWIPS/NAWIPS display is not feasible as it will be extremely distracting and time consuming. The problem with providing a probabilistic approach is that you are removing the detailed information that the forecasters would like to see but currently do not have to time to look at. So what do we do?

An interesting solution to this problem arose during a car ride on the way to pick up dinner this evening during a break in EWP operations. Why not provide a display that looks similar to a binary yes/no product, but be able to (on mouse-over perhaps) interrogate all of the interest field information? Currently within AWIPS you are able to do this for a single field. For instance, you can display radar reflectivity and interrogate the actual dBZ value on mouse-over. What if it were possible to provide information from multiple fields on mouse-over in this similar manner while still providing a simple to understand one-size-fits-all display for the product? Some food for thought.

Daily debrief... 9 June

Today we met up with the EWP forecasters following the joint EFP/EWP daily map discussion and talked a little about what happened yesterday. Since there was some interesting weather from yesterday we had a good chance to capture some feedback from the forecasters regarding the experimental products...

Convective Initiation

- UWCI triggered CI occurring right as the appearance of a 50 dBZ echo on radar... it was so unstable that it didn't really have much of a chance.

- "I liked the cooling cloud tops product... gave you some awareness of what storms you should pay attention to during warning ops and which ones were strongest."

- "I found it useful this week and look forward to that era when we can get those increased temporal refresh rates. This would be very useful."

- In a more dynamic situation this could be very useful.

We asked the forecasters if they had a preference to see more or less signal (more vs less FAR)...

- "I like looking at them both side by side... you can come up with a poor man's ensemble for CI because we know the limitations of both."

- "There may actually be a benefit of some false hits because it may be telling you that the cap is strong... it can give you a sense of what's going to happen in the short-term."

Nearcast

- The precipitable water product did give a sense of where the convection would start over SW WI.

- There was a sharp theta-e gradient and that seemed to be where storms focused.

Overshooting-tops / Thermal Couplet

- Thermal couplet showed up over SW WI, but warning was already issued and radar was showing clear signals of severe weather.

- Interesting to see all the thermal couplets over northern Maine... might be a good case to examine.

- There were many overshooting tops over the WI area, however forecasters were too engulfed in the rapidly updating radar data.


Today EWP warning operations are going to stick around New England with the ongoing severe convection. We are hoping that some storms can back-build towards the DCLMA so that we can get some PGLM data, although this is conditional. We may also target over Oklahoma if things get going there, but that too is very conditional.

Killing Time..

Sitting amongst the many weather aficionados, scientists, and forecasters in the HWT, the afternoons convective activity is being actively discussed, weighed, and contemplated. Where will be the area of interest be for the afternoon that all of the groups will place their focus?

While all of this goes on, I have been spending my time listening and watching the satellite and radar displays, checking to see how SATCAST is doing. Early this morning, a short finger of clouds sitting diagonally over eastern Iowa, northern Illinois and southern Wisconsin triggered some convection along the line. An example of new convection just north of the main line is shown below producing radar echoes in about an hour. This was repeated along the line in the 2-3 hour period I was watching.

AWIPS Display at 1332 and 1432 UTC.
In other parts of the country, mostly around the Gulf of Mexico, the last few days have provided lots of examples of individual instances along the coast and across Florida where SATCAST was able to forecast initiation with an average of 30 - 45 minutes of lead-time. Radar images taken from the NWS radar pages...


As the afternoon progressed, the number of storms that were caught and developed into the late afternoon all along the Gulf Coast did a good show showing the utility of the SATCAST algorithm.

SATCAST images at 1732 and 1745 UTC.
Mobile, AL radar at 1744 and 1826 UTC.
Tallahassee, FL radar at 1743 and 1829 UTC.
For today, the SATCAST image at 1715 UTC with corresponding imagery from the NWS’s regional weather radar loops, the CI indicators are starting to verify to the south along the coast, while faint radar echoes are becoming visible to the North and East into Alabama, Georgia, Tennessee and North Carolina.

Lower images, 1758 and 1918 UTC SE Region radar image

A rough day all around for CI forecasting

To bring us up to date, yesterdays forecast domain for the afternoon warning program forecasters centered on the area covered by the Grand Forks and Duluth CWAs. These areas were decided upon using the inputs from all of the participants of both the EFP and EWP, based on model input, observations, and the vast experience present in the room. My last entry ended with a dinner break to pass the time waiting for CI to initiate somewhere... anywhere.

Unfortunately, Mother Nature did not cooperate and the area stayed pretty well capped into the forecast period. In the short time I was away, the decision was made to shift the focus area to Bismarck, ND, where we had a better chance of seeing some storms. Shortly after my return, some storms popped, giving the forecasters something to look at, analyze, and even issue some statements and a warning on.

So how did SATCAST do? Well, we got the convection in North Dakota as the system moved east, approaching out original focus area. It did catch the 3 cells that caused the increased activity, with lead-times of about 30 minutes as well as some other areas of convection as the afternoon progressed.

SATCAST image at 1845 UTC
The area of clouds (marked by the green arrow) consistently flagged CI in subsequent satellite images. These storms started to show up on radar at 1958 UTC and went on to be warned on as early as 2330 UTC.

NMAP2 radar reflectivity at 1958 UTC.
NMAP2 radar reflectivity at 2337 UTC.
Unfortunately, SATCAST also indicated CI sporadically across the northern part of Minnesota that never had a chance of getting to verify. The capped environment just couldn't be pushed through by the rapidly growing systems that tended to pop up along the boundary. End result, some False Alarms.

A known problem area of the techniques includes high CAPE areas that are capped. The algorithm exploits the satellite signals to flag rapidly growing clouds. Although there are post-processing techniques in place to help eliminate false alarms (such as masking out areas that have no CAPE) it doesn't pick up as well in areas where significant CIN is also present. We as a research group are still hunting for the "best" way to reduce the false alarms without masking out the good data. Also compounding the problem in this area, was the presence of high level cirrus associated with the low-pressure system. The cloud-typing algorithm does a good job identifying ares that need to be masked out, yet high level cirrus seems to be the bane of both CI algorithms tested during this experiment, as evidenced by the CI flags along the boundaries of the system as the afternoon progressed.

In contrast, the UWCI algorithm did not have as many CI flags in the Grand Forks/Duluth focus areas. The one or two flags they did have, verified shortly thereafter. And yes, the UAH SATCAST algorithm did pick up on those cases as well. To be fair, I did not get a chance to see if UWCI flagged the storms in the Bismarck area later, so I am only commenting on the 2-3 hours over the first focus area. But it does bring up an interesting question, is it better to have a few indicators that verify at the cost of missing many of the other cases, or is it better to have more indicators in/of the environment, that although will catch the definite cases of CI, but will also result in higher false alarms?

I asked each of the forecasters and got a few different answers. For one, watching where SATCAST flagged rapidly growing clouds caused him to focus in on the associated environment to ensure a good understand of what is occurring at that time and check for agreement with previous thinking. If he wasn't looking at it, he was checking to see if the environment had changed since he looked last. In short, a situational awareness tool. For another, watching where the algorithm was flagging CI ahead of the warning area he was responsible for queued him in to watch for radar echoes. There were also some statements indicating that the jury was still out. Overall, a broad spectrum of answers yet not overall negative, especially after playing with both tools for only one day. I imagine that in the next day or two, more definite opinions will be formed and shared...

Then again, isn't that the point?

Impressions of a first day...

Sitting through the various discussions on the likelihood of the development of CI, it quickly became apparent that the low pressure system moving eastward along the Canadian border was garnering plenty of interest from the 3 main desks located in the HWT. Watching it through the morning with the morning shift of EWP forecasters, the area remained on the "it's going to be an interesting day" and "it didn't really produce much" line, due to the favorable conditions in moisture and afternoon heating being held back by a pretty definite cap that may or may not break sometime before 00Z. Moving in the afternoon, warning portion of the EWP program, conditions remain decent, yet the cap is still firmly in place. Interest in the CI products is in the forefront of the forecaster's minds and the handy, four panel, product is up on the main screens of the AWIPS displays of all four forecasters present.

In all, so far, SATCAST has been indicating CI sporadically in and around the North Plains for most of the afternoon. Taking into account the capped environment, the algorithm has been picking up the signal of rapidly growing clouds, as it is trained to do, yet convection has been slow to develop in CWA's of Grand Forks and Duluth. This has resulted in some red objects (in the area of interest) that will likely not verify, due to the capped environment and some interfering cirrus atop the low pressure system as it moves east.

So far, the forecasters have still indicated an interest in the product as the afternoon has progressed. Being able to look at the data in a loop has allowed for an awareness of the environment, allowing for the forecaster to be "queued in" to an area of interest. As an example, the UAH CI algorithm has indicated a consistent CI signal moving across western North Dakota that verified about 35 minutes later on radar (according to the notes of forecasters assigned to the Grand Forks CWA).

It is still early, we will see how things evolve after a quick dinner break..

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.

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.

CI over New York

Another busy day for the EWP forecasters, as severe thunderstorms have erupted over the mid-Atlantic region. As so, screen captures from AWIPS have been tough to come by. Therefore, these next screen shots come from NAWIPS.

SATCAST CI has performed very well over the New York and Pennsylvania areas this afternoon. The following satellite image is from 1945 UTC. SATCAST forecasted CI over south central New York. Approximately 13 minutes later, radar reflectivity exceeded 35 dBZ on the base scan. While not the largest lead time, in another large CAPE environment, SATCAST is performing well.


SATCAST is performing quite well today pinpointing areas where storms will develop in the future. Even in Florida, where the dynamics are not as impressive, storms developed with help from convergence by the sea breeze, and SATCAST provided a very good forecast.

SATCAST CI detected underneath cold core low

Oklahoma was under the gun yesterday, but is under a completely different convective regime today. As the cold core low continues to shift eastward, clear morning skies have created an area of convective instability that has led to convective shower development.

SATCAST has been developed to try and diagnose convection of all types, not necessarily areas of severe weather. SATCAST forecasted CI in northern Oklahoma at 1832 UTC (upper panel of top image). 38 minutes later at 1910 UTC, radar reflectivity exceeded 35 dBZ at -10 C (bottom left panel of bottom image). No severe weather will come of this activity, yet it provides forecasters with the ability to let the public know via short term forecasts that convective showers are developing, and changes to outdoor plans may need to be changed.

NSSL-WRF simulated GOES-R products

GOES-R visiting scientists discussed with NSSL scientist Jack Kain about the possibility of creating NSSL-WRF simulated GOES-R convective initiation products. Since the model has very short time-steps (24 seconds), following cloud 'objects' via the SATCAST overlap method should be relatively simple. From this, a cloud top-cooling rate and other CI fields, such as cloud-top glaciation, would be easy to produce. Hopefully in the future we may be able to start producing this and other unique GOES-R products that we can not currently produce from observational sensors.

CI beginning to occur over south central MO

Despite EWP operations being canceled for today, monitoring of experimental products continues. As the strong cold core upper level low continues to churn eastward, new thunderstorm development continues to erupt in Missouri as daytime heating combined with mid-level cold air advection erode the cap. SATCAST CI has recently forecasted new convection to develop in this region. An example is presented in the images below:

In the upper image, SATCAST is predicting convection to fire somewhere near the circled area at 1645 UTC, as SATCAST currently predicts which cloud objects are forecast to initiate, but now exactly where it will do so. Not there is no convection currently at the same time (lower right panel in top image).

In the lower image, radar imagery shows greater than 35 dBZ at 1726 UTC, approximately a 41 minute lead time. No lightning had been generated as yet, but the storms to the north have quickly become severe, and it sure appears as storms form further south, that they will also become severe.

In a future blog post, we will try to look at other areas of the country where severe weather is not anticipated if the weather cooperates.

SATCAST captures storm that produced estimated 1.75" hail

The SATCAST CI algorithm forecasted CI for an initial development on the dryline. Horizontal convective rolls were evident in satellite imagery which intersected with the dryline. Due to the busy nature of the day today, images were captured using NAWIPS rather than AWIPS. Therefore, the only comparison to be made is between the SATCAST (upper image) and base reflectivity (lower image).




Forecasters participating in the EWP estimated that SATCAST gave approximately 10-15 minute lead time on the intial appearance of 35 dBZ at -10 C. It gave a 33 minute lead time compared to base reflectivity. The storm has produced ~1.75" hail stones. As of writing, the storm is now producing a small rope tornado.

The storms are in a ripe environment to develop quickly, therefore it has been imperative GOES be in rapid scan mode as storms produce a cirrus shield within 15 minutes of development. Both CI algorithms have performed remarkably in such a volatile environment. Both continue to forecast CI along the southern end of the dryline.

Convective initiation along sw OK dryline

Forecaster comments reposted from EWP blog...

Convective inititation occured along the southwest OK dryline. According to UAHCI and CIMMS CI products, had about 10-15 minute lead time for storm near Altus. 30 minute lead time from UAHCI and 20 mintue lead time from CIMMS CI for storm near Sayer.

Horizontal convective rolls east of sw OK dryline suggest storms may form in the warm sector too…maybe!

Pablo, Rudoph, and Bobby

Both CI products capturing initial development of convection

Both CI products captured convective initiation in and near the Oklahoma panhandle this afternoon. Utilizing our 'ultimate_ci' procedure within AWIPS, I screen captured both the initial development of convection and further convective development farther east. See image above. The given images for CI products are valid for the 1645 UTC imagery, and you can see the general areas flagged by the algorithms. The bottom left panel of the four panel is reflectivity at -10C. The reflectivity product was not working earlier than 1745 UTC; therefore, what is shown is the first available image. As you can see this flagged convection has attained values around 55 dbZ showing that these CI hits were correctly flagged.

This second image shows both products correctly capturing CI within the 1710 UTC imagery. Querying the reflectivity at -10C, the cell at 1732 UTC had yet to attain greater than 35 dbZ with a max value of 28 dbZ. This cell would later attain greater than 35 dbZ approximately 30 minutes after initial CI flagging. As of the end of this blog post, these initial storms are still going strong.

SATCAST captures initial CI along dryline

At 1855 today, SATCAST flagged development occurring in Beckham county in Southwest OK (top left panel).



Forecasters have been waiting for the convection to develop along the dryline in West Oklahoma during the afternoon hours. Despite an environment characterized by MLCAPES greater than 3000 J/kg, SATCAST was able to have a lead time of approximately one hour before 35 dBZ reached the -10 C isotherm (bottom left) and lightning as detected by the PGLM (bottom right).


The early storms of the afternoon struggled initially develop, but have started developing rapidly in recent time frames. SATCAST has caught many of the storms which have developed along the dryline this afternoon as GOES is currently operating in rapid scan mode.

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.