GLM offset with ltg jump

GLM overlaid with ENTLN data showing GLM offset to the northwest of the storm.  Ltg jump occurred over the few previous frames as storm seemed to cycle again, with dBZ nearing 75

Late December storms

A negatively-tilted shortwave brought some low-level moisture return to the gulf states this week, and with the moisture, some scattered severe storms.

A couple tornadic storms affected portions of east Texas. The NOAA/CIMSS ProbSevere model now incorporates the GOES-16 satellite growth rates, and a storm affecting Cherokee Co., TX, had a strong normalized growth well before it produced severe weather.

Figure 1: AWIPS2 screen captures of MRMS MergedReflectivity, ProbSevere contours, and NWS warnings for a storm near Rusk, Texas.

The ProbWind values vacillated largely between 50% and 75% for this storm, before producing a tornado at 00:56 UTC and multiple wind damage reports in the town or Rusk, TX. The strong GOES-16 vertical growth rate, large ENI flash rate (~30-70 fl/min), and stout kinematic fields (eff. bulk shear ~ 45-50 kts; meanwind 700-900mb ~ 35 kts) combined to produce these moderate-strong ProbWind values. The MRMS MESH remained rather low (~ 0.2 - 0.6 in), signaling that this was not a severe hail situation. ProbTor had a maximum value of 12% before the first tornado report.

This storm featured jumps in ProbWind value (one produced by a large increase in flash rate, indicative of a lightning jump), and being an outlier storm amongst its neighbors, in terms of probability value. Both features in ProbSevere objects have been identified by forecasters as indicating possible severe weather.

A second storm formed further south and later in the night, which also produced a damaging tornado, touching down northeast of Beaumont, TX, and later northwest of Lake Charles, LA, blowing off the roof to a restaurant.

Figure 2: AWIPS2 screen captures of MRMS MergedReflectivity, ProbSevere contours, and NWS warnings for storm heading into southwest Louisiana.

The kinematics for this storm were very favorable, with effective bulk shear of 50 kts, meanwind 700-900mb of 45 kts, and 0-1 km storm-relative helicity near 300 J/kg. The first tornado touched down at 07:41 UTC, when ProbTor was about 30%. ProbTor then jumped from 30% to 50% at 08:00 UTC, the time of the second tornado report. This jump in ProbTor value was coincident with an increase in total lightning (a lightning jump) as well as an increase in low-level rotation.

Figure 3: Time series of ProbTor and predictor values for this storm affecting southeast TX and southwest LA.

A tornado warning was issued at 08:10 UTC, when ProbTor had just increased to 90%. The third tornado reported, at 08:20 UTC, was rated EF1 and destroyed the roof of a restaurant in DeQuincy, Louisiana.

Week 4 (9-13 May 2016) Summary and Feedback

The final week of the 2016 GOES-R/JPSS Spring Experiment concluded with our two pairs operating in the Nashville and Huntsville CWAs. Both were able to evaluate the PGLM product via the Huntsville LMA.

LAP
- Convection developed along the moisture and instability gradients in LAP.
- I liked seeing the model data where retrievals were unavailable. In addition to having a continuous field, it often allowed for quick comparisons of retrievals with nearby GFS.
- Our office does look at K-Index for flash flood situations.
- 30-min is a good temporal update frequency. Too frequent of updates would not be that useful, as such fields do not change so rapidly.
- Layer PW was my favorite LAP product as it was most unique, and added value to my analysis. It was particularly useful on days when we had strong low-level moisture advection, tracking the movement of moisture, and dry air aloft.

GOES-R CI
- When I had 1-min imagery, I did not need CI because I could identify areas of imminent CI in the imagery.
- In situations where you are expecting severe thunderstorm activity, you's look more at severe CI. Regular CI was not as useful for severe situations because you could see cb development in the 1-min data.
- When looking for general thunderstorms, I see CI being more helpful, including in the cool season. This would be valuable for DSS purposes.
- I found utility in having both CI products up. If severe CI was pinging on something in addition to regular CI, it helped to focus attention to particular areas of interest.
- It would be helpful to see probability trends for a particular cloud/area.
- We were fine with the display concept
- I like the current instantaneous visualization  over a smoothed probability field approach.

ProbSevere
- It would be nice to see a meteogram with a history of ProbSevere probs.
- Everyone is fine with the display and color-scale.
- Similar to VIL of the day, might be helpful to determine "ProbSevere Prob" of the day.
- I think it really well with discrete cells, but later would merge nearby cells.
- I would say this was my favorite product outside of the 10min imagery.
- I thought it performed great this week.
- We would all use this in operations.
- I've worked 5 or 6 severe events in the last month, and I've ProbSevere up for all of them. Usually I have storm relative velocity all tilts, regular velocity in the middle, and the third screen has different fields, including composite reflectivity with ProbSevere. I've also even started putting it on all-tilts. The display does not distract me. In my office, the threshold to warn depends on the day, but I've found with most of our events, especially with severe wind, we can get severe with a threshold of ~60%. Definitely not using it as a yes/no.

SRSOR
- All forecasters loved using it this week!
- 5-min is certainly bettern than 15. But when you are tracking low-end severe situations, subtle boundaries can make all the difference between something going up or not. We get better than 5-min radar data, but 1-min satellite data can fill gaps that we still have. 5-min will be useufl, but 1-min is optimal.
- I think it is certainly time to make the jump to 1-min satellite imagery. There is so much that can be seen, even outside of convection. Forecasters need to use satellite data more in day to day operations.  Generally, I think forecasters don't think satellite imagery is as useful as it is, and they have a hard time understanding exactly how much they will see in the 1-min imagery.
- It was helpful to view long loops of the 1-min imagery on the regional scale to get a big picture idea of how the system was evolving.
- It was really helpful for analyzing frontal structure and all the different boundaries.
- Satellite imagery is truly the only visual representation you have of a storm that you can't get with any other product.
- I found it useful to match 1-min lightning data with 1-min satellite data.

SRSOR Winds
- I liked the winds a lot. You could see the vertical structure of a front, and how winds changed with height from the surface. Seeing rapid change over a short vertical distance was intriguing. AMV's could be a big help with our TAFs.
- I felt that the low-level winds were more useful than the upper-level winds. They indicated areas of low-level convergence, moisture transport, veering of winds from the surface, potential for tornadoes.

Lightning Jump
- I liked it more as the week went on. I usually used it in tandem with ProbSevere and PGLM Flash Extent Density. I could see all of these being in a 4-panel and helping with situational awareness for severe operations. Especially on Thursday, I noticed the storms with the biggest LJ's were the ones that strengthened considerably thereafter.
- I'll be interested to use this during cool season events, as I am always looking for more information in these situations.
- I like the way it is now, though I can see others preferring a contoured look.
- I like a 4-panel layout with ProbSevere, lightning jump, Severe CI, Lightning, composite reflectivity, and satellite imagery.
- Forecasters are/will always change to their preferred color tables.
- There will always be a spot for a product like Lightning Jump in my display.

GLM Total Lightning
- The lightning data will be very helpful for DSS - events, fairs, etc. It will be very helpful to have this information updating every 1 minute.
- Especially for cool season events, we are always looking for more data. Lightning from satellite will be helpful.
- I can see this being helpful in EM's decisions to evacuate stadiums.
- This will be big for us during fire weather season in the NW US.
- In the future, with lightning in field offices, there must be very good training on all of this. There is/will be a lot of different lightning data. Generally, forecasters do not know the differences in lightning verbage.
- I will likely overlay it on radar or satellite.
- LMA-1 was the favorite among the group

NUCAPS
- The plan view and cross-section components were my favorite aspect of NUCAPS this week
- The lure is that it is an observation. I think it should remain observationally driven, even though we know there could be a source of error. If so, we know the source of the error. If you add in model data, you don't always know the source of the error.
- Pop-up skew-T will be good to use before and during an event with NUCAPS.
- Modification is not an issue for me. In our office we modify RAP soundings all the time. It takes some time, but it works. 
- NUCAPS has a lot of potential, but a lot of bust potential for captivating an office.
- I can't get anyone to look at it in my office in Portland.
- The lack of detail is a killer. That's why I think plan view and cross section displays are more valuable.
- People will use it if they see the value, and it is made clear that this is an observation.

General
- Participants felt that the start of week orientation/familiarization was great.
- It was the perfect amount of products to evaluate.
- It would be nice to have a DRT WES case for slow days.
- I suggest having a group briefing after the groups complete their mesoscale analysis but before CI.
- The broadcaster commented that this was a great experience, and it was wonderful to be able to work directly with NWS forecasters.
- Some of the training material should be put on the CLC so we can go back and look at it in the future.

Broadcast media perspectives of new products

This week I was lucky enough to experiment with tools and products that will help forecasters make faster and more accurate decisions regarding severe weather.  As someone who works on the TV side of things, I have a different view of how useful these products could be to me and my colleagues.  While the forecasters main goal is to issue timely warnings to save lives and property, my goal is to quickly and clearly communicate warnings and threats to the public, via tv, social media. etc... .
While ALL the products are valuable, there are several which I would think would be most beneficial to me if I had them available to me to share with viewers

1 minute VIS. Satellite- Total eye candy...after all I work in a visual world. The stunning displays would give our viewers something to look at, and I could point out certain features that concerned me (rapid development etc...).

Lightning Jump- Another one of my favorite visual tools.  I would use a modified version of this, and obviously the language wouldn't be "sigma".  I could however imagine a version of this where the categories were small-moderate-large-extreme...or negative.  It would be easy to communicate quickly that if we see these jumps, that means the potential is there for severe storm development, or at least these storms warrant close watching.  Once storms reach severe levels I'm not sure I would continue to use that tool.  I believe I would switch at that point to PGLM.

PGLM- I would use this tool to track severe storms and show the lightning.  We currently show lightning flash counts, and the viewers love it, but I would prefer the visual display presented as it is in PGLM.

PROB Severe- Initially I was ALL FOR IT.  I loved the outline display.  After tracking storms in the Southeast today where the product under-performed due to a different atmospheric environment, an environment that is much closer to my home one, I changed my mind.  If this product could be fine tuned specifically for region or season, then I would LOVE to show viewers a severe probability parameter storm cell by storm cell.

CI & CI Severe- Still unsure of the value this would have to viewers.  If there were no storms present, but storms expected I could see this being something that could help show storm potential, but I would want to have higher confidence in the product.  I would probably also only want to show probs of 80 or higher on air. 

Even though I wouldn't necessarily use the assessment products on air (LAP, NU CAPS) I am glad that NWS forecasters will have these available because I see their value as well.  

-StormFront

1 Min Visible Sat Shows Convection Developing on Outflow Boundary

We noticed an outflow boundary moving into our CWA from the Huntsville CWA to our south. Convection is developing along this line and is producing several cells that are generating quite a bit of lightning activity.

 
We issued a severe thunderstorm warning on one of the cells for Coffee, Warren, and Grundy conties that produced a significant lightning jump. The flash extent density value reached around 40. -JP

Daily Summary: Week 4, Day 3 (11 May 2016)

For Wednesday, the groups began operations in the Fort Worth and Pueblo CWAs. It quickly became apparent that Pueblo activity would remain marginal, so that group moved to the Springfield CWA. With convection slow to develop in FWD, that group transitioned to the San Angelo CWA.

LAP
- It showed abundant isntability in central Texas. CAPE, LI, and PW were all on par with what we had expected.
- Looking at layer PW in Pueblo, there was an enhanced area of ll moisture in the SE corner of the state, but activity never made it there to tap into it.

CI
- CI values increase quickly before initiation.
- It was helpful in highlighting development along the outflow boundary, and where along the outflow convection would develop.
- Early on, there were low percentages where nothing happened, so did not see any false alarms.
- It hit on storms in the Midland area where we weren't really expecting any development.
- In Springfield, one cell popped up right on the boundary that eventually produced severe hail near St Louis. It had very high regular CI, and 70 severe CI.
- I noticed regular CI hitting on development south of Pueblo CWA.

 ProbSevere
- Our one hail-maker in St Louis made it into the 90s. ProbSevere did well on that cell. Otherwise, we didn't see many storms go over 10, which was good since we didn't have any other severe.
- In Texas, I saw my first 100. Mesh was over 2" We issued a tornado warning on that storm.

SRSOR
- I wrote a blog post on the importance for forecasters to back up and look at the wider view, noting important features. As more OTs develop, one can visualize the linear structure across the region. One could see the evolution of boundaries and their interactions with each other. Inflow into storms from the south was apparent via the movement of low level clouds. While the initial outward expansion of teh anvil was in all directions, it backed up on one side due to the opposing mean flow at that level. Lots of waves were apparent. There are a lot of features and processes that you just cannot see with routine data.
- There was a mature storm with large anvil. New storms formed beneath the anvil along the outflow boundary. We could see the storms mature as they rose through the anvil.
- With a cell in Springfield, the updraft looked vigorous but then died quickly. We could see this in the 1-min imagery as it happened. The 1-min imagery has been helpful for rapidly developing storms, allowing you to see what is happening right away. 
SRSOR winds
- In Springfield, as cu developed, winds were available at many levels, allowing us to analyze the presence of directional shear (winds were veering with height). South of our CWA, we saw low level convergence, but in our area, flow was uni-directional. That convergence never made it into Springfield, and the lack of low-level support is likely why convection did not develop.
- In San Angelo, convergence was apparent along the outflow via the satellite-derived wind field.

Lightning Jump
- With storms in Texas, a 3-sigma lightning jump helped me make my warning decision.

NUCAPS
- Pueblo is not an upper air site, so it was helpful there. IASI NUCAPS indicated only weak instability, which made sense given only weak convection/showers. Surface dew point and temperature were very accurate, perhaps because the atmosphere was so dry.
- In Texas, we used NUCAPS in our early analysis which proved to be helpful given sparce UA obs.
- NUCAPS had Wet Bulb Zero heights around 9000 ft, and FL around 12000 ft. Wit the kind o updrafts we had, I am not surprised we had such large hail.

2330 UTC: SJT Severe Convection

The storms really got rockin' in SJT forecast area.  The cell in the northern portion of the forecast area developed a hook echo. At 2330 UTC a distinct jump occurred in the lightning data to +3 sigma.  Also, clouds tops continued to rapidly cool.

The hook echo was well-defined at 2333 and it was decided to issue a TOR (see below)

The SRM and Velocity data were very impressive from the KDYX radar. The cursor highlights close to 75 kts on the edge of the old SVR polygon below.

The satellite signatures continued to be impressive in the TOR box (-73C pixel), but new cells began to form further south, and additional SVR's were issued based on the PROB Severe values shooting up to 90-99%, and the overshooting tops in the satellite and IR data (see the 4-panel below).

Overall, it was a great close to a slow starting day.

-Yodamaster777

Daily Summary: Week 4, Day 2 (10 May 2016)

For the second day of week 4, our two groups operated in the Fort Worth/Dallas, TX and San Angelo, TX CWA's. Severe convection developed along the dryline across central Texas.




LAP
-  CAPE values were slightly less than those from RAP, but I understand this because GFS was fairly low, which is used as the first guess in the retrievals. Although, RAP may have been high.
- The LAP CAPE gradient was right through our CWA. It was helpful to focus on the location and movement of this gradient, as convection developed right along it.
- Layer PW was helpful for identifying drying aloft. I thought with wind and hail, and TPW values being relatively low, this seemed correct.
- LAP LPW showed really dry air aloft. This was apparent in the RAOBs, and confirmed in LPW.

GOES-R CI
- It was not good yesterday in FWD. We didn't see any probabilities from severe or regular CI despite having cu develop and initiate into severe storms. There did not appear to be cirrus contamination.
- There were instances when severe CI was higher than regular CI
- In San Angelo, things were slow to get going. Early on, there were no probabilities until convection had already began to develop. Later in the day it was better. It keyed in on new development further south when we were focused on the ongoing convection to the north.

ProbSevere
- For the first storm of the day that got a warning yesterday, I was very confident that it was going to go severe. It looked good on radar with a strong reflectivity core. I put a warning on it despite probsevere being only 40-50%. After the warning, the storm weakened pretty quickly. Lightning and shear had both been low.
- Yesterday, if probabilities went over 80, I thought it had a good chance of going severe.
- I went liberal on one warning. Without ProbSevere I would have waited to warn. It definitely added lead time in that situation.
- Through using ProbSevere, I could see warning lead time going up, but also FAR rate increasing.
- Towards the end of the day yesterday, probsevere was in the 90s with a storm, but based on radar reflectivities, it appeared that the storm was weakening. Lightning flash rates were high at this time.

Lightning Jump
-Training needs to be improved for this, as I did not understand the LJ before using it yesterday
- I noticed a lot of fluctuations in LJ in a cell.
- It helped with my confidence, seeing jumps with the rapidly developing storms
- I liked using the 4-panel with ProbSevere and LJ together. The first time I used the two together, ProbSevere gave me more confidence in what I was seeing in radar, and LJ gave me confidence in what I was seeing in Probsevere. I liked this.
- I didn't feel like I needed to see a new lj to warn, but it added confidence.
- For me, it was more a a SA tool, alerting us to cells that we hadn't really been watching yet but needed to start keeping an eye on. It was an early indication that we need to look at the storm further.
- I actually liked the display, the blob really jumps out. We aren't really interrogating radar in that panel anyway, so it is fine that it gets covered up.
- I could see LJ being a confidence booster in pulse thunderstorm cases. Maybe not as much with a qlcs event dropping wind damage, when we know it is severe.

SRSOR
- With one storm I was watching, a storm split was obvious in the 1-min imagery much earlier than it was in the radar imagery.
- I could see the strengthening of the updraft and OT well in multiple supercells quicker than was apparent in radar.
- I enjoyed looking at IR imagery. The OTs as indicated by areas of very cold temperature were pretty brief, but the 1-min imagery was able to capture them. They weren't long-lived OTs, occuring in-between radar and routine satellite scans. So it was helpful to have this rapidly updating information.
- I could see the Overshooting Tops shoot up before strengthening in radar.
- With a cell that ended up being severe, you could see it forming along the outflow boundary before you could tell what was going on in radar.
- It was easy to see cu clouds feeding into the supercells
- It was informative to observe low clouds moving under the anvil, a depiction of deep layer shear.

SRSOR winds
- Early in the day and in the 18z radiosonde, there was not much shear. But later, the satellite-winds indicated strengthening westerly flow aloft.
- Helped to find areas of low-level convergence.
- The winds indicated convergence along a boundary ahead of the dryline. We did get enhanced cu development in this area. The winds alerted us to areas of concern.
- When upper-level winds came in with a storm anvil, we could see veering with height.
- This will be useful in extracting a pseudo wind profile, and monitoring layer wind shear.

NUCAPS
- Looking at the Plan view and cross section displays in FWD, I think these can be very helpful.
- Mixing ration plan view at 700 mb showed a nice gradient near the CWA boundary. Convection was dying as it crossed this gradient into the drier air.
- The highest mixing ration values were collocated with the storms in Mexico.
- The NUCAPS data is a great check on the models
- NUCAPS matched closely with the nearby Del Rio sounding in terms of CAPE and PW.
- It reinforced my understanding of the present thermodynamic environment.
- Prior to CI, I would look at NUCAPS while gauging the environment.
- If we do an 18Z sounding, then get NUCAPS a couple hours later, the temporal change would be helpful to see.
- I do not want to have to modify a NUCAPS sounding in the middle of warning operations.
- With the plan view, it was easy to pick out areas of bad data. So in this case, I would not want a model adjustment. But I would want an adjustment to the actual profile.
- I like the idea of not using model data for the low-level correction. I think it would be better to do whatever correction you can with available observations.
- Even without the 18Z sounding, I think NUCAPS would be helpful, assuming you have someone to modify the sounding. This would fill the gap of no 18Z special sounding.
- 130 PM timing for NUCAPS is perfect. It is right before CI usually.
-

MAY 10, 2016: FWD Finale

...Severe storm heading to the Fort Worth and the Dallas Metro-Area...

A full blown MCS formed along the western portion of the Dallas-Fort Worth forecast area.  Several large hail reports came in, but a severe mode switch to damging winds, as the the low-level velocity data had a broad area of 45-60 kts 2-3 kft AGL (not shown). The Prob Severe (below) value was still 93%, but this cell was tapping into nearly 5000 J/kg of MUCAPE.  Likely the DCAPE values were close to 2000 J/kg. The cloud tops had cooled close to -65C. This particular cell was heading to Dallas-Fort Worth over the next hour.  Significant wind damage is likely.

Brief summary...

Overall, the Prob Severe guidance, and Lightning Flash Rate Algorithm were very helpful today for issuing warnings.  The 1-min GOES-14 SRSOR imagery beautifully showed the CB  and anvil evolution.  Also, clouds tops cooled to close to -75C with one cell in the FWD area.


-Yodamaster777

2138, 2143 and 2149 UTC SVR's: KFWD

A couple of severe thunderstorm warning were issued based on the Prob Severe Values being 99% coupled with the radar data (2138 UTC storm).  This storm looked capable of producing damaging winds and large hail, as it had a low-level wind max descending out of the storm.  The storm became a left mover as it split from the original storm. The storm is depicted below.

The 2140 UTC storm had the 60 dBz reflectivity echo core lifted to 35 kft AGL, well above the -20C height of 22 kft AGL.  It had impressive upper level divergence signature with a tripole of 3 sigma lightning jump increase seen in the upper left panel below. The middle segment was where the warning was issued at 2143 UTC.

The final image shows all 3 warnings as of 2149 UTC...they are coincident with the LTG jump(s).

-Yodamaster777/Jason Bourne

May 10, 2016: First Warning for KFWD

The first Severe Thunderstorm Warning was issued at 2055 UTC, as the Prob Severe jumped and steadied at 55%.

It should be noted that a 2-sigma jump in  LJDA also occurred. See below...

-Yodamaster777/Jason Bourne

Daily Summary: Week 4, Day 1 (9 May 2016)

The final week of the HWT 2016 GOES-R/JPSS Spring Experiment has begun! The GOES-R/JPSS Proving Ground/User Readiness meeting is taking place here in the National Weather Center in Norman also this week. Attendees to that meeting will be visiting the HWT to get a first hand look at the evaluations currently taking place. Day 1 of the final week was a busy one, with severe convection, including confirmed tornadoes, near Norman. Below are some photos from the day, along with feedback from our daily debrief.

Photo of large tornado that formed near Sulphur, OK (south of Norman) courtesy of our HWT/EWP Operations Coordinator, Gabe Garfield.

Looking at a tornado-warned storm east of Norman from the roof of the NWC. Radar image and warning are in figure to right.

LAP
- I like looknig at the LPW, especially in the lowest level, because you could see where the moisture transport was. It gives you more information than just TPW. I see this being useful for seeing moisture return from the GoM, as different flow regimes often bring moisture up into a region.
- I thought LPW was helpful. I appreciated that the mid and upper layers showed drying aloft, with greater moisture at the low-levels.
- It was nice to see the dry line depicted in the low layer LPW field.
- CAPE values matched up with 18z Norman sounding, and SPC mesoanalysis.

CI
- In Norman CWA, it highlighted the main area of convective development in the western part of the CWA. It was a little slow, however, as I could see the devleopment in visible imagery by the time the CI algorithm . targeted it.
- The strongest storm in the Norman CWA that produced a large tornado had a 70% severe CI on it.
- If a product performs well over time, I have confidence to use it later.
- In the NW part of the Norman CWA, a line of severe storms had a severe CI over 50 prior to development
- In FWD, an area had high CI well ahead of initiation, and severe CI around 50. This was higher than the rest of the region, so it attracted our attention. This area ended up developing and becoming severe.
- This is a product that, if you can trust it, was good in the situation we had yesterday. I was paying so much attention to our one tornadic storm. Then to the south, there was a cluster of high CI that brought my attention down there. Without CI, I would not have looked down there as early as I did.
- I can see this being useful in the southeast US. With pulse severe thunderstorms and large CWA's, storms could develop anywhere on the map in a given day. This product helps a forecaster with where to look next.

 ProbSevere
- I noticed large jumps in ProbSevere simultaneous to storms increasing in strength, so it didn't give us much of an increase in lead-time yesterday. We tended to see large jumps at about the same time that we normally would have issued based off of standard data. For us it increased confidence in these warning decisions.
- I think it is especially helpful for the first cells of the day. ProbSevere jumped into the 60s. It was helpful for marginal cells at the beginning of the shift that were on the edge of becoming severe.
- Later, cells were obviously severe based on other datasets, so it wasn't as helpful. But still, it was great for confidence, especially watching trends in the probabilities. It is also helpful to see the predictor output.
- I like this product a lot, I am already using it in my office (RAH)
- I was most confident to issue at the 80% threshold
- Yesterday in FWD, the rapid increases in probabilities helped. The rate of change of probsevere triggered a severe tstorm warning. I wonder if a rate of change of probsevere prob could be a product on its own.
- It was very helpful to see why the probabiltiies changed via the predictors.
- With the first cell, we issued a warning when we saw probs quickly go from 45 to 65. No lightning wit hthis storm.
- In busy situations, it is helpful for discriminating storms that are more likely severe vs those that weren't. I don't remember a high probsevere yesterday that did not warrent a warning.

SRSOR
- Seeing OTs at this temporal resolution was helpful; it allowed us to figure which storms had the strongest updrafts at any given moment.
- For initial development along the dryline, convection went up very fast. Without 1-min data, we wouldn't have been able to recognize so soon that convective initiation was occurring.
- This validate dthe CI product. I'd see soemthing on CI and then go to 1-min data to validate it.
- 1-min imagery changes the game for interrogating storms before they are seen on radar.
- Having 1-min data available to see things earlier allowed me to get the alert out sooner.
- Seeing stuff go up earlier was the greatest benefit to me. I have an earlier idea of where the strong updrafts were.

SRSOR winds
- In FWD, I noticed a difference between the RAP analysis and satellite-derived winds. The RAP had significant LL convergence that was not apparent in the SRSOR winds. Nothing ever developed in that area. My initial discussion mentioned this, and how the satellite-winds made me doubt that covnection would develop since I was not seeing convergence. Also, not much directional shear.

Lightning Jump
- There was a 26-sigma jump on the tornado-producing cell prior to it producing a tornado, but we had already warned on it.
- I prefer the ProbSevere contour display over the LJ blog display.

NUCAPS
- If we hadn't had the 18Z RAOB, it would have been useful. 18Z soundings told us what we needed. 20Z NUCAPS matched up well.
- NUCAPS didn't resolve the CAP in the FWD CWA; this was a downfall. The 18Z FWD radiosonde showed that the CAP was actually still present.
- Having NUCAPS 1 hour earlier would have helped with the severe weather in the Norman CWA.
- The parameters matched up well with other data sources after I correct it.
- We have NUCAPS set up in our office. We've had success in using it to determine elevated convective potential, seeing moisture coming in around 600-700 mb, closed lows over CA.
- In warning siutations, having to put so much effort into modifying the sounding is a deal breaker.
- I think if you have a mesoanalysis on shift, they would look at NUCAPS during severe weather operations, and provide updates to the radar operators.
- For me, the most useful aspect of NUCAPS was for checking instability. Those values looked on par yesterday, telling us that  the environment would support severe storms.
- I would be fine with having an error line visible in NSHARP with NUCAPS. Training on this would be important.

Using Prob Severe and Lightning Jump data together

When using Prob Severe and Lightning Jump together there was some conflicting information as Prob Severe was increasing while lightning jump was decreasing and then increasing. It did not really influence my warning decision all that much but did make me stop and think about it for a while. In the end it probably cost me a couple minutes of lead time. Once the trend in lightning jump reversed both products gave confidence to a warning. Also this storm was was coming out of the ICT radar and in the absence of other radar data...using prob severe and lightning jump data meant that I was not as dependent on the radar data as I normally would be. This was a plus and a confidence booster. There certainly was utility in using both of these products. I could definitely see incorporating both of these into my normal warning process. Below is a gif of how the two products worked in tandom with the lightning jump decreasing while the prob severe was increasing.

 

-Jason Bourne

GOES Prob Severe Increased Confidence in Issuing Severe Thunderstorm Warning

We issued a Severe Thunderstorm Warning for 3 counties in NW OK around 20Z.
Using a traditional forecasting methodology of looking for 60dBZ up to the -20C level, we determined that severe hail was becoming a possibility.

The GOES Prob Severe product increased our confidence in making this decision. Around the same 20Z time period, the Prob Severe jumped from around 40% to 75% over a short period of time. We also saw a lighning jump of about 2 sigma during this time as well. These products didn't neccessarily increase our lead time, but increased confidence.

WUUS54 KOUN 092006
SVROUN
OKC003-093-151-092045-
/O.NEW.KOUN.SV.W.0142.160509T2006Z-160509T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE
306 PM CDT MON MAY 9 2016

THE NATIONAL WEATHER SERVICE IN  HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN WOODS COUNTY IN NORTHWESTERN OKLAHOMA...
  CENTRAL ALFALFA COUNTY IN NORTHWESTERN OKLAHOMA...
  CENTRAL MAJOR COUNTY IN NORTHWESTERN OKLAHOMA...

* UNTIL 345 PM CDT

* AT 305 PM CDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
  CAPABLE OF PRODUCING LARGE HAIL UP TO PING PONG BALL SIZE AND
  DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED 7 MILES
  WEST OF ORIENTA...OR 10 MILES NORTHWEST OF FAIRVIEW...AND MOVING
  NORTHEAST AT 65 MPH.

* LOCATIONS IMPACTED INCLUDE...
  CHEROKEE...CARMEN...CLEO SPRINGS...JET...ALINE...LAMBERT...GREAT SALT
  PLAINS LAKE AND ORIENTA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...DESTRUCTIVE HAIL...DEADLY
LIGHTNING AND VERY HEAVY RAIN. FOR YOUR PROTECTION...MOVE TO AN
INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY
RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER
COVERS THE ROAD.

&&

LAT...LON 3670 9813 3628 9855 3638 9874 3683 9834
      3697 9812
TIME...MOT...LOC 2005Z 214DEG 58KT 3639 9860

$$


JFP/TAW


- JP/Yodamaster777

Week 3 (2-6 May 2016) Summary and Feedback

Week 3 concluded out West, with participants forecasting for the Boise and Pendleton CWA's. Severe activity was once again marginal, but there were enough storms to keep participants busy evaluating the products.

LAP
- Values (where we had retrievals) matched NUCAPS, which matched with modified observed soudings and observed soundings throughout the week.
- LAP retrievals seemed to correct underdone GFS CAPE throughout the week.
- It was helpful to have PW broken up into a few layers
- Layer PW gives you a good sense of where differential moisture advection is occurring.
- I liked that GFS filled the gaps in retrievals. It was also nice to compare the retrieval data and model data.

CI
- I would load it in my office; the information was useful.
- The regular CI product performed great this week.
- CI trained your eye to focus on areas of cloud development. I used it several times for situational awareness. It gave a lot of lead-time in DC, where it told me to watch that area prior to development.
- I see this being greatly improved with 5-min updates from GOES-R
- Generally we all liked the display.

ProbSevere
- The display made sense, and I adapted to it fast
- Ideas for predictors that might improve probabilities include: low-level divergence signature in velocity data for wind events, DCAPE for wind, surface-based theta-e for derechos, surface cold pool difference for wind.
- All said that it would be helpful to have the probability broken down be severe threat. They would load it as a 4-panel.
- Loved it, great tool
It tends to blend together nearby storms.
- With the storm on the west side of DC, we had a storm split, but ProbSevere grouped the storms together, so it was unclear from which cell the information was coming.
- I would like it to be able to differentiate storms, especially in linear events.
- There is already getting to be a lot of information in the readout, adding more might get to be a lot. It would be a good idea to color the data, or make the output selectable by the user.
- On marginal days, it confirmed what we were thinking about the storms.
- On one of the marginal days, we warned on a storm that reached 50%. It seems like you need to guage the threshold for each particular day
- ProbSevere and lightning jump give you added confidence to issue warnings or continue warnings if on the bubble. Good warning decision tools.

SRSOR
- We would like to have both the regular imagery and Parallax-correct imagery available to us. There were cases when it helped but also a case where it hurt.
- I wish the 1-min imagery was available more often.
- I can't wait to get this from GOES-R
- I think this will be beneficial for tracking the development and evolution of lake effect snow, where you have low-topped, but intense growth. For me this will be the case on Lake Michigan.
- I see myself using the 1-min imagery during warning operations.
- I compared satellite and radar imagery side-by-side. This allowed me to match storms, and compare storm behavior in the two.
- I overlayed IR and visible imagery. This allowed me to see cloud top trends, temperatures, etc plus the detail in one panel.
- I loaded warning polygons on the srsor imagery. This allowed me to match with storms in radar more easily.
- I could see a visible cloud line along the rear flank downdraft.
- We depended on the 1-min imagery even more when we were operating out west.

SRSOR winds
- Participants would like having a gridded analysis of these winds, in addition to the wind barbs themselves. Fields like wind speed, divergence, and vorticity would be helpful. It is sometimes difficult to visualize these fields from just the barbs.
- On Monday in W Maryland, I could see low-level mass flux occuring in the vicinity of a cloud line. It was nice to quantify it with the winds.
- It would be nice to somehow automate the computation of layer shear.

Lightning Jump
- ProbSevere and Lightning Jumps give you added confidence to issue warnings or continue warnings if on the bubble. These are good warning decision tools.
- I would like to see how negative jumps correlate to echo top collapses.
- I like the colors. They grab my attention. The upper threshold should be increased.

 NUCAPS
- It would be neat to add winds to the profile. Some sources could be surface obs and satellite derived winds.
- We would like to see the surface modifications be automated.
- It was helpful to have the plan view displays. I would like to see fields like theta-e, cape, pw, height of freezing level, height of -20C level

General
- All commented that they enjoyed the experience, and it was just the right amount of products to evaluate.
- It would be nice to have a WES case for slower days.
- After initial assessment before convection starts, have a group briefing to see what the two groups were observing.
- Broadcaster said it was a great experience, and it was beneficial to work alongside the NWS forecasters.

Overview of Thursday, May 5, 2016.

Today, we were in the Pendleton, OR CWA, for a Marginal Risk from SPC. The  main feature to focus on were 500 mb vorticity maxima moving northwest into the region during the afternoon. This would combine with cold temperatures aloft to product ample MUCAPE. Deep layer shear was relatively strong (40 to 50 knots) in the eastern portions of the area, weaker to the west.

The LAP products provided good estimates of CAPE during the afternoon, when sampled with the cloudy sky data. There were not many locations that had this, but was inferred to be over most of the area with the modified NUCAPS soundings. Using these products together helped gain confidence in the amount of CAPE over the area.

The GOES winds also helped with estimating the deep layer (700 mb to 250 mb) shear over the area, as the afternoon evolved. This was handy to assess the environment and storm mode.

The CI product was helpful with showing CI potential, despite middle to high clouds blocking some areas. The CI values were low in these areas, but would have been much higher had there not been any middle to high clouds. Using the 1-minute SRSOR imagery to watch the cumulus development, and radar to confirm cell development, these low CI values were a clue that initiation was likely.

I did not get a chance to use Prob Severe and lightning jump much, as the convection was not strong. Some cells had enough lightning flash rates to bring the Prob Severe values to 30%, but they would weaken within a few radar volume scans. No lightning jumps were detected.

JJW

Daily Summary: Week 3, Day 3 (4 May 2016)

Today was a very quiet day. One group operated in Florida (Miami and Tampa Bay), monitoring ongoing convection coming off the GoM. The other group operated in the Memphis CWA, tracking sub-severe convection associated with a cold core low advancing through the region.

LAP
- Correctly increased CAPE... GFS has been underdone for CAPE each day this week, so it was nice to see LAP correctly increase the values.
- Clear sky and cloudy sky retrieval values were closer to other data sources than were GFS values.
- Convection developed within the max in LAP PW, which was maximized vertically through the atmosphere at that location as seen in layer PW
- Participants commented that they like the inclusion of GFS model data to fill holes in retreivals

CI
- Pinged development in S Florida
- It worked well for us yesterday.
- There were some that it missed, but there were hits too.

ProbSevere
- Never got out of the single digits. It was still useful information, since convection was not severe
- Having estimates of CAPE and shear were useful
- Confirmed our thinking of what the mesoscale environment would  be like
- It did pick out cells within the large cloud shield
- Broadcaster: In my office, we use GR, so we could pull in probsevere files

SRSOR
- In the mid-level cloud plume along the pre-frontal trough, it was helpful to see convective clouds poking through.
- It is helpful to compare SRSOR with radar imagery to match up cells
- I liked the sandwich product, this would be helpful to watch in real-time

SRSOR winds
- The winds nicely showed the shift with drier air moving through.

Lightning Jump
- The few jumps we had were low, which fit the situation.

NUCAPS
- I looked at NUCAPS offshore, which showed drier air aloft, which made sense as drier air was moving in.
- The modified sounding over W TN showed around 500 j/kg of CAPE, which looked right, giving we confidence in how the environment had evolved since 12Z.
- With the Plan view displays it was helpful to see the environment at a particular level.
- With the plan view, you can quickly see how the airmass is changing, more or less stable, based on mid-level cooling temperatures which steepens lapse rates
- The Plan view display is most beneficial in the clear sky pre-convective environment
- I would use theta-e to diagnose areas of CSI and strong frontogenesis.

End of Day 3

A quite day in the MEG CWA as storms struggled to develop along the western flank of a mid level trough associated with cold core low dropping south out of the Great Lakes.  However with that said, GOES CI did do well in depicting eventual development through the central/eastern portions of the CWA by mid afternoon in proximity to maximized GOES LAP derived total PW gradient and where the greatest concentration of storms were observed.

In addition, per general weak cloud growth noted in 1 min SRSOR visible imagery and limited MESH, prob severe remained in the single digits which confirmed the weak/shallow nature of the convection that did manage to develop.  Limited lightning production in even the strongest cells did not meet the 10 strike/min minimum for the lightning jump algorithm to activate.

Tornadotod

Day 3 Wrap Up...Not much to write home about...

Note: The CG Lightning Probability product is not a GOES-R or JPSS funded project.

Well...what can I say... not much convection to speak of today anywhere in the CONUS. There were some thunderstorms that moved through Central and Southern Florida earlier this afternoon but nothing was severe. That being said...I found that the ProbSevere, Lightning Jump and CG Lightning Probability algorithms were still able to pick up on convective cells even in a messy environment. This is very promising!

~Lilly Miller~

Useful Products for TV Mets

It has been a great experience seeing the different products perform this week during the experiment.

As the TV meteorologist in the group, I have seen what could be useful during the preparation of the forecast and during the weathercasts.

The three products that stand out to me are: Prob. Severe Model, Lightning Jump Detection Algorithm, and the 1-minute GOES imagery.

Most of the time we have to be careful with what we show our audience because it might be too much for them to digest and understand, which we don't want to happen. The weathercast is supposed to be easily understood by everybody.

As long as we explain what we are showing, I believe the Lightning Jump Detection Algorithm and Prob. Severe Model could easily be integrated into our radar software to show these features on air that could give our viewers ample lead-time with severe t-storms. I am hoping WSI can bring these features into their software with future builds.

Last, the 1-minute satellite imagery would look really good in HD and be another tool in our back pocket to track subtle features that might be missed with our current 15-30 satellite updates.

-BW