Today we had the opportunity to debrief our final group of forecasters for the first time this week. Most of yesterday was spent familiarizing the forecasters with the products in AWIPS II. Below are some comments gathered during today's debrief...
SATCAST / UW Cloud-top Cooling
- "In Tulsa's area, SATCAST strength of signal was always under 40 or so... at one point it did start to develop a consolidated area just south of I-40 where it was an area that was associated with some enhanced low-level moisture convergence... nothing really happened, but it was still interesting to see the evolution. The values were still low, so I wasn't really expecting much to happen... it was nice to be able to have some confidence that CI might not occur."
- "We had a little bit down in Birmingham's area and we did see some strength of signals reaching 80 and those did develop and some became severe, so it did a nice job."
- "We had a couple CTCs reach near -20 C / 15 min and we did see a cold pool coming down, so we did go ahead and trigger a warning on it... The one tower that cooled the most was the one that went up the fastest and was associated with some high winds later on."
- "Some of those that were to the north of HUN's area did have some significant CTCs but nothing happened... there were only a couple of these... it seemed like the FAR was pretty low."
Nearcast
- "It was telling us that the axis of instability was going all the way to the coast (and it did) and that would be a huge thing to know, whether the convection would continue or die."
- "In the Tulsa domain, looking at the low level PW and theta-e, it was really showing the drying coming down.... the surface obs saw this too, but it was still interesting to see that and how it affected the convection."
PGLM
- "We saw some increases in lightning activity, but I wouldn't say it became an indicator one way or the other... but we were dealing with an ongoing MCS, so there may not have been many changes going on... it did not sway us in our warning decision."
- "There wasn't much lead time on the occurrence of CGs... they seemed to happen at the same time of the ICs... but again, we were dealing with an MCS."
- "At a CWSU, if I had this data everywhere it would be huge because you may not have any 'ground truth' from CG data with storms that may still have tops up to 32k ft and producing IC flashes that you don't want any planes flying into."
- "It was nice because you can't really see any sort of jumps in lightning from CG data alone."
- "We did have two 60 mph wind reports near Mussel Shoals that were associated with some increases in lightning activity."
Tuesday, June 12, 2012
Monday, June 11, 2012
HUN: NowCast #3 1833 CDT Monday 11 June
Forecaster comments from EWP blog...
Thunderstorm line moving across Lauderdale, Colbert and Franklin counties starting to indicate potential of weakening slightly next 1 to 2 hours. Storms are initiating along the leading edge of a strong cold pool…and that process will continue farther east into the current SVR tstm warning polygon. WoF indicating updraft strength weakening slightly past few passes, and the lightning rates have shown a decrease over the past 4 passes. Expect to see 50+knot winds along and behind the bow to continue being brought down at times next hour…but for areas farther east suggested to have a slightly more stable airmass in place in the GOES Vertical Theta-e Diff Low-Mid imagery…which would suggest the threat might diminish as the storms approach the Cullman and Huntsville areas. Stay tuned.
Thunderstorm line moving across Lauderdale, Colbert and Franklin counties starting to indicate potential of weakening slightly next 1 to 2 hours. Storms are initiating along the leading edge of a strong cold pool…and that process will continue farther east into the current SVR tstm warning polygon. WoF indicating updraft strength weakening slightly past few passes, and the lightning rates have shown a decrease over the past 4 passes. Expect to see 50+knot winds along and behind the bow to continue being brought down at times next hour…but for areas farther east suggested to have a slightly more stable airmass in place in the GOES Vertical Theta-e Diff Low-Mid imagery…which would suggest the threat might diminish as the storms approach the Cullman and Huntsville areas. Stay tuned.
HUN: NowCast #2 1733 CDT Monday 11 June
Forecaster comments from EWP blog...
UAH_CI and CIMSS Cld Top Cooling imagery indicating potential for stronger storms over southwestern forecast area…mainly Franklin, Lawrence and Cullman counties next hour or so. Continue Severe Thunderstorm Warnings for Franklin and Colbert counties but threat passing south of Limestone county. May see shallow spinnup on the leading edge of the bowing structure moving into Red Bay area…but nothing to warn on for tornadoes right now.
UAH_CI and CIMSS Cld Top Cooling imagery indicating potential for stronger storms over southwestern forecast area…mainly Franklin, Lawrence and Cullman counties next hour or so. Continue Severe Thunderstorm Warnings for Franklin and Colbert counties but threat passing south of Limestone county. May see shallow spinnup on the leading edge of the bowing structure moving into Red Bay area…but nothing to warn on for tornadoes right now.
HUN: NowCast #1 1705 CDT Monday 11 June
Forecaster comments from EWP blog...
Nearcast Vertical Theta-e Difference forecast fields showing deeper
layer instability ahead of the squall line moving southeast across
Mississippi and will increase across Northwest Alabama over the next
three hours. We don’t expect a lot of weakening of the strong to severe
storms along the line moving southeast passing north of Tupelo into NW
Alabama. CIMSS CI-Layer cloud top cooling rates now around -23C
indicative of strong updrafts in storms north of Tupelo…and pGLM 1 minute composite showing an increase to 4 over past 5 minutes…and
increasing updraft strengths. Given the environment, we expect to see
an increased risk of severe storms with damaging winds in excess of 60
mph, frequent lightning over Franklin Colbert and Limestone counties
over the next 1 to 2 hours. Storms over northern Mississippi past half
hour still indicating localized winds to near 70 mph, according to
spotter reports out of the Memphis NWS Foreccast Office.
TSA — Looking for CI
Forecaster comments from EWP blog...
Looking at the various CI products for the TSA CWFA. With the strong
EML, it may be tough for the cap to break today with sfc temps only in
the lower 90s. Seeing a little more organization in the UAH CI product
along the front, but it is possible that we will need to switch domains
in the next hour or so if we do not see better development.
MCS in MEG – storm environment
Forecaster comments from EWP blog...
Started looking at NEARCAST 780-500mb CAPE vs RAP13 (aka RUC13) 850-700mb computed CAPE. 2hr fcst valid 2200UTC. Realizing that we cannot compare these two fields 1-for-1, the NEARCAST CAPE seems more accurate compared with the location of the MCS precip and cloud field.
See the vis satellite image and obs from 21Z for more “truth”.
We expect the storms along the leading edge and flanking edge to the
west of Memphis along I-40 to continue to intensify. Will continue to
watch the NEARCAST and CI images for new trends.
Started looking at NEARCAST 780-500mb CAPE vs RAP13 (aka RUC13) 850-700mb computed CAPE. 2hr fcst valid 2200UTC. Realizing that we cannot compare these two fields 1-for-1, the NEARCAST CAPE seems more accurate compared with the location of the MCS precip and cloud field.
Final week
We are underway with our 5th and final week of the experiment. This week we have 6 forecasters from across the country looking at the various experimental products we have available. Today we are working with the forecasters to familiarize themselves with the AWIPS II environment, and also load the experimental products into AWIPS II.
Friday, June 8, 2012
EWP week 4 debrief
Today marks the end of 4 weeks of operations in the EWP. Today we had the opportunity to debrief the forecasters on their experience here over the past week.
SATCAST / UW Cloud-top Cooling
- Yesterday's event over Boulder CWA... "We did try to warn on the CTC a couple times with ongoing severe to the north, the first storm quickly disappeared, but the second one was successful... we did get 1.5" hail out of it."
- "I can definitely see the utility of the products in focusing your attention on what is developing."
- "There were a couple instances where the SATCAST would have a lot of 'confetti', but there weren't any really strong signals... it really showed the utility of having the strength of signal instead of a yes/no."
- "The probabilities for the SATCAST did seem to match up with the overall occurrence of CI."
- "I may have only seen one case this whole week where the -20 C /15 mins signal in the CTC had any severe after it... I think there could be more work done to fine tune those values." - There seems to be some environmental dependance that could be playing a role in how successful the threshold values are in relating to severe weather... It has performed well over past weeks, but in some situations (like the past couple days) the occurrence of severe after a strong cooling rate may be less common.
- "I really liked that 'Ultimate-CI' 4-panel you guys had... that was nice... I would steal that."
Simulated Satellite
- "I found that the placement of convection was really good... the biggest weakness was the timing and the coverage of the storms... I see this as a 'top of the pyramid' product where I will start to get an idea of what's going on over my CWA."
- "It also picked up on the non-convective stuff (jet streaks/shortwaves) really well with the WV."
- "It would be great to get this in GFE."
- "I looked at the band difference, but I didn't really see the utility of it... granted I was more focused on the IR and WV which was more intuitive to me."
- "When we got set up, there was almost always stuff on radar, so we didn't really have much of a use for it."
Nearcast
- "I used it both as a forecast tool and an analysis tool."
- "A lot of the time this week the clouds were just too thick and made it hard to use."
- "I put the OUN WRF reflectivity on one panel with the CAPE and Theta-e products... the convection followed the CAPE/theta-e areas well... it was an interesting way to display it."
- "It was nice that you could use the GOES-E and GOES-W and overlap them to give you the complete picture... the values were a little different where they overlapped, but it still gave you a good picture."
- "It would probably be more useful in the early afternoon."
Sounder Airmass RGB
- "We ingest the other NASA sport RGB products and the color tables were so different for the airmass product that I got a little confused." - They were referring to the MODIS version of the RGB airmass, which does have some different color aspects.
- "I did look at it once and it did pick up on a lot of the larger scale features very well."
PGLM
- Yesterday's event over Sterling CWA... Had a lot of trouble with sensors failing over DCLMA and causing serious detection efficiency issues.
- "Like I said the other day... 5- and 15-minute composites would be great in addition to the 1-minute data."
- "The color curve was a little hard to see, especially for the lower flash amounts."
- "Lightning jumps aren't easily seen in the 2D gridded display... especially at 8km."
- "It would be really cool to see this over smoke plumes... we have seen some CG strikes from smoke plumes before."
Overall / Training
- It was reiterated that for some of these limited coverage datasets (ie - PGLM), it would be nice to have a map of the coverage.
- "The biggest negative was the satellite outage issue... it always seemed to happen right when everything happened." - 1800 and 2100 UTC are prime times for convection... and are also when 30-minute full disk scans occur.
- "Winds an turbulence are our biggest threats (CWSU aviation)... especially relating to non-convective weather and they are hard to pick up on with radar data alone."
- "I thought the change to having a training shift before you arrive was a great idea... it was overall very smooth."
- "I definitely felt more comfortable finding the products yesterday than I did day 1... It might be helpful to just sit down for an hour or two with someone and load the products."
- "Having procedures for the products really helped."
- "Having everything in AWIPS II was fantastic... we really got some good hands on experience with how the products will be used in the future."
- "I really liked the discussions with the developers... it really helped us understand how the products worked."
- "Having a level of uncertainty or confidence displayed within the products is very useful."
SATCAST / UW Cloud-top Cooling
- Yesterday's event over Boulder CWA... "We did try to warn on the CTC a couple times with ongoing severe to the north, the first storm quickly disappeared, but the second one was successful... we did get 1.5" hail out of it."
- "I can definitely see the utility of the products in focusing your attention on what is developing."
- "There were a couple instances where the SATCAST would have a lot of 'confetti', but there weren't any really strong signals... it really showed the utility of having the strength of signal instead of a yes/no."
- "The probabilities for the SATCAST did seem to match up with the overall occurrence of CI."
- "I may have only seen one case this whole week where the -20 C /15 mins signal in the CTC had any severe after it... I think there could be more work done to fine tune those values." - There seems to be some environmental dependance that could be playing a role in how successful the threshold values are in relating to severe weather... It has performed well over past weeks, but in some situations (like the past couple days) the occurrence of severe after a strong cooling rate may be less common.
- "I really liked that 'Ultimate-CI' 4-panel you guys had... that was nice... I would steal that."
Simulated Satellite
- "I found that the placement of convection was really good... the biggest weakness was the timing and the coverage of the storms... I see this as a 'top of the pyramid' product where I will start to get an idea of what's going on over my CWA."
- "It also picked up on the non-convective stuff (jet streaks/shortwaves) really well with the WV."
- "It would be great to get this in GFE."
- "I looked at the band difference, but I didn't really see the utility of it... granted I was more focused on the IR and WV which was more intuitive to me."
- "When we got set up, there was almost always stuff on radar, so we didn't really have much of a use for it."
Nearcast
- "I used it both as a forecast tool and an analysis tool."
- "A lot of the time this week the clouds were just too thick and made it hard to use."
- "I put the OUN WRF reflectivity on one panel with the CAPE and Theta-e products... the convection followed the CAPE/theta-e areas well... it was an interesting way to display it."
- "It was nice that you could use the GOES-E and GOES-W and overlap them to give you the complete picture... the values were a little different where they overlapped, but it still gave you a good picture."
- "It would probably be more useful in the early afternoon."
Sounder Airmass RGB
- "We ingest the other NASA sport RGB products and the color tables were so different for the airmass product that I got a little confused." - They were referring to the MODIS version of the RGB airmass, which does have some different color aspects.
- "I did look at it once and it did pick up on a lot of the larger scale features very well."
PGLM
- Yesterday's event over Sterling CWA... Had a lot of trouble with sensors failing over DCLMA and causing serious detection efficiency issues.
- "Like I said the other day... 5- and 15-minute composites would be great in addition to the 1-minute data."
- "The color curve was a little hard to see, especially for the lower flash amounts."
- "Lightning jumps aren't easily seen in the 2D gridded display... especially at 8km."
- "It would be really cool to see this over smoke plumes... we have seen some CG strikes from smoke plumes before."
Overall / Training
- It was reiterated that for some of these limited coverage datasets (ie - PGLM), it would be nice to have a map of the coverage.
- "The biggest negative was the satellite outage issue... it always seemed to happen right when everything happened." - 1800 and 2100 UTC are prime times for convection... and are also when 30-minute full disk scans occur.
- "Winds an turbulence are our biggest threats (CWSU aviation)... especially relating to non-convective weather and they are hard to pick up on with radar data alone."
- "I thought the change to having a training shift before you arrive was a great idea... it was overall very smooth."
- "I definitely felt more comfortable finding the products yesterday than I did day 1... It might be helpful to just sit down for an hour or two with someone and load the products."
- "Having procedures for the products really helped."
- "Having everything in AWIPS II was fantastic... we really got some good hands on experience with how the products will be used in the future."
- "I really liked the discussions with the developers... it really helped us understand how the products worked."
- "Having a level of uncertainty or confidence displayed within the products is very useful."
Thursday, June 7, 2012
BOU: Here we go!
Forecaster comments from EWP blog...
Well…we decided to issue our first experimental warning based on the UW-CTC. Let’s see what kind of lead time we get!
CTC rates were around -20C/15 min and we are just beginning to see some reflectivity.
We will update to let you know if we get any verification or if this turns out to be a false alarm!
Update: A great question was just posed: do you plot the warning downstream of the developing storm based on the Warn-on-Forecast? Or do you just use the CTC as a ‘red flag’ and follow the development as it progresses…issuing the warning at a later time?
CTC (upper right image on left panel) with first severe thunderstorm warning (right panels)
Well…we decided to issue our first experimental warning based on the UW-CTC. Let’s see what kind of lead time we get!
CTC rates were around -20C/15 min and we are just beginning to see some reflectivity.
We will update to let you know if we get any verification or if this turns out to be a false alarm!
Update: A great question was just posed: do you plot the warning downstream of the developing storm based on the Warn-on-Forecast? Or do you just use the CTC as a ‘red flag’ and follow the development as it progresses…issuing the warning at a later time?
CTC (upper right image on left panel) with first severe thunderstorm warning (right panels)
Update: 2207z….
We issued another warning based on CTC! We seemed to kill any
potential with the first CTC-based warning… perhaps this one will work
out!
Trends on MESH and reflectivity have improved on this storm and now appears severe on radar.
Update: 5:43pm CDT... VERIFIED! 1.50″ 4:30pm local time (MDT)!! The initial warning was issued at 4:07pm MDT.
CI products on the front range
Forecaster comments from EWP blog..
Watching for CI in CO. We have noted moderate to high SOS hits on the
higher terrain of CO west of DEN (1930Z and 2015Z images shown). Up to
this point this activity has yet to convect. Conditions are ripe so we
will see when it does take off.
Update: This initial activity did not convect.
1932 UTC
2015 UTC
Update: This initial activity did not convect.
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