Below is a photo from the week 3 Tales from the Testbed webinar.
Friday, May 6, 2016
Week 3 Complete!
Although a much quieter week (severe-weather-wise) compared to last, we still had quite a productive time in the HWT. Monday was the busiest day of the week, with widespread severe weather in the Mid-Atlantic states, including a storm that moved through the DC metro. Tuesday was similarly active, while Wednesday and Thursday were our least active days of the experiment. These days allowed the forecasters to evaluate the products in more marginal environments, which is equally as important as the busy days. Thursday the groups got to operate in the western US, where radar coverage is not as good, making the satellite products even more important there.
Below is a photo from the week 3 Tales from the Testbed webinar.
Below is a photo from the week 3 Tales from the Testbed webinar.
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.
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.
Thursday, May 5, 2016
Day 4 Wrap Up...Another lack-luster day...
Today we were forecasting for Boise, ID. There was a marginal severe weather risk out for portions of the area. During the early afternoon there was a lot of cirrus clouds moving through the area. This limited many things...including the low level AMV's, CI and Severe CI, LAPS data, and NUCAPS soundings. That being said...we were still able to get a good NUCAPS sounding later on in the evening that seemed representative of the environment.
For warning operations...however...I mainly relied on radar data from multiple sites and 1-minute visible satellite imagery to account for any terrain blockage and for the lack of additional data. CI and ProbSevere didn't pick up on much except for the one storm that was warned on (the BOI forecast office warned on it too). Below is an animation of the convection across ID and OR today...
Overall...warning operations in the west is definitely more difficult than in the eastern CONUS. The base radar data and 1-minute visible imagery were the keys to situational awareness and warning operations today.
~Lilly Miller~
For warning operations...however...I mainly relied on radar data from multiple sites and 1-minute visible satellite imagery to account for any terrain blockage and for the lack of additional data. CI and ProbSevere didn't pick up on much except for the one storm that was warned on (the BOI forecast office warned on it too). Below is an animation of the convection across ID and OR today...
 |
| GOES-15 in Rapid Scan Operations |
~Lilly Miller~
End of Day 4
A generally uneventful day for the BOI CWA. Widespread pesky cirrus cloud debris negated much usefulness with GOES CI. On the other hand prob severe did provide useful information with high based convection that developed over southern Idaho with one lone vigorous storm prompting the only severe thunderstorm warning of the afternoon.
GOES LAP once again provided good environmental data in clear sky retrieval areas over the northern/central CWA and of which matched nicely with surface parcel modified 2103Z NUCAPS pass. Otherwise limited lightning production resulted in no viable lightning jump output. Finally, given limited low level satellite derived wind information prior to convective initiation across northern NV and southern ID, GOES SRSOS 1 min visible imagery proved valuable in providing low level cumulus cloud tracer motions.
Tornadotod
GOES LAP once again provided good environmental data in clear sky retrieval areas over the northern/central CWA and of which matched nicely with surface parcel modified 2103Z NUCAPS pass. Otherwise limited lightning production resulted in no viable lightning jump output. Finally, given limited low level satellite derived wind information prior to convective initiation across northern NV and southern ID, GOES SRSOS 1 min visible imagery proved valuable in providing low level cumulus cloud tracer motions.
Tornadotod
Day 4 Wrap Up Report
As the week goes on (no pun intended), the threat for severe wx continues to decline.
We were assigned the Pendleton CWA today. The LAP product panel earlier in the day didn't look too impressive with regard to severe thunderstorms. There were a few ordinary thunderstorms that popped up and many were terrain driven today.
What I took away from the day today is that when there is sparse radar coverage in the CWA (i.e. out west), the GOES 1 minute imagery really helps to detect the towering CU in the region.
-BW
We were assigned the Pendleton CWA today. The LAP product panel earlier in the day didn't look too impressive with regard to severe thunderstorms. There were a few ordinary thunderstorms that popped up and many were terrain driven today.
What I took away from the day today is that when there is sparse radar coverage in the CWA (i.e. out west), the GOES 1 minute imagery really helps to detect the towering CU in the region.
-BW
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
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
CI gives a lead time of 45 minutes!
The highest CI of the day matched up with the highest ProbSevere Probability...so far! The CI algorithm showed a 61% probability at 2030Z. Then...as convection formed and moved northwest towards that specific area where the CI was...the cell intensified and became severe. By 2215Z, the ProbSevere probability peaked at 50% (without any satellite information) and a warning was issued!
~Lilly Miller~
 |
| Convective Initiation Algorithm at 2030Z |
 |
| ProbSevere Probability overlaid with ENI Total Lightning and 1-minute SRSOR Visible imagery at 2215Z |
~Lilly Miller~
NUCAPS Sounding Showing Increasing MUCAPE And Lower 0C/-20C Levels!
The adjusted NUCAPS sounding, taken near KBNO, just southeast of the Pendleton, OR CWA, showed MUCAPE values over 1200 J/kg at 2100 UTC. This was higher than the 800 J/kg estimated at 1800 UTC earlier (off of the 1200 UTC BOI sounding).
This made sense, as the LAP CAPE product in the upper left image below showed similar values in the cloudy sampled areas (the yellow areas in the upper right image) at 2100 UTC. There is some caution here, as the complex terrain may affect CAPE values in some areas. Still, the NUCAPS sounding gave an idea of how the instability has evolved this afternoon across the area.
In addition, the 0C and -20C levels from the NUCAPS sounding were lower (by a few thousand feet) than the modified 1200 UTC sounding from Boise, ID. This gave me a heads up to lower these levels for monitoring storms. The NUCAPS soundings seem to be a good situational awareness tool! JJW
This made sense, as the LAP CAPE product in the upper left image below showed similar values in the cloudy sampled areas (the yellow areas in the upper right image) at 2100 UTC. There is some caution here, as the complex terrain may affect CAPE values in some areas. Still, the NUCAPS sounding gave an idea of how the instability has evolved this afternoon across the area.
In addition, the 0C and -20C levels from the NUCAPS sounding were lower (by a few thousand feet) than the modified 1200 UTC sounding from Boise, ID. This gave me a heads up to lower these levels for monitoring storms. The NUCAPS soundings seem to be a good situational awareness tool! JJW
GOES Winds Detecting Strong Shear Aloft!
The GOES winds in the lower left corner of this 4 panel image shows 718 mb level winds of 14 knots, and 275 mb level winds at 77 knots, in north central Wallowa County at 2150 UTC. This would give approximate deep layer shear (in the 720 mb to 275 mb layer) of 63 knots. Pretty strong shear, and a great way to get the latest shear values across this area! JJW
BOI pulls the trigger...
Vigorous high based storm now ongoing south of Jordan Valley. Per steady escalation of prob severe and 55 dBZ core aloft in deeply mixed environment pulled the trigger on a severe thunderstorm warning for potential damaging winds.
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BOISE ID
401 PM MDT THU MAY 5 2016
THE NATIONAL WEATHER SERVICE IN BOISE HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
WEST CENTRAL OWYHEE COUNTY IN SOUTHWESTERN IDAHO...
EAST CENTRAL MALHEUR COUNTY IN SOUTHEASTERN OREGON...
* UNTIL 500 PM MDT
* AT 401 PM MDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM
WAS LOCATED 28 MILES SOUTHWEST OF SILVER CITY...OR 30 MILES EAST OF
ROME...AND MOVING NORTHWEST AT 45 MPH. PENNY SIZE HAIL MAY ALSO
ACCOMPANY THE DAMAGING WINDS.
* THIS SEVERE THUNDERSTORM WILL REMAIN OVER MAINLY RURAL AREAS OF
WEST CENTRAL OWYHEE AND EAST CENTRAL MALHEUR COUNTIES...INCLUDING
THE FOLLOWING LOCATIONS: LITTLE GRASSY RESERVOIR...AROCK...DANNER...
COW LAKES...SOUTH MOUNTAIN...ANTELOPE RESERVOIR...NORTH FORK OWYHEE
CAMPGROUND...CLIFFS...LITTLE GRASSY MOUNTAIN AND CASTRO RIDGE.
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 4267 11680 4255 11708 4299 11764 4316 11722
TIME...MOT...LOC 2201Z 145DEG 38KT 4267 11705
$$
TORNADOTOD
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE BOISE ID
401 PM MDT THU MAY 5 2016
THE NATIONAL WEATHER SERVICE IN BOISE HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
WEST CENTRAL OWYHEE COUNTY IN SOUTHWESTERN IDAHO...
EAST CENTRAL MALHEUR COUNTY IN SOUTHEASTERN OREGON...
* UNTIL 500 PM MDT
* AT 401 PM MDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM
WAS LOCATED 28 MILES SOUTHWEST OF SILVER CITY...OR 30 MILES EAST OF
ROME...AND MOVING NORTHWEST AT 45 MPH. PENNY SIZE HAIL MAY ALSO
ACCOMPANY THE DAMAGING WINDS.
* THIS SEVERE THUNDERSTORM WILL REMAIN OVER MAINLY RURAL AREAS OF
WEST CENTRAL OWYHEE AND EAST CENTRAL MALHEUR COUNTIES...INCLUDING
THE FOLLOWING LOCATIONS: LITTLE GRASSY RESERVOIR...AROCK...DANNER...
COW LAKES...SOUTH MOUNTAIN...ANTELOPE RESERVOIR...NORTH FORK OWYHEE
CAMPGROUND...CLIFFS...LITTLE GRASSY MOUNTAIN AND CASTRO RIDGE.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...DESTRUCTIVE HAIL...DEADLY
LIGHTNING AND VERY HEAVY RAIN. FOR YOUR PROTECTION...MOVE TO AN
INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY
RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER
COVERS THE ROAD.
&&
LAT...LON 4267 11680 4255 11708 4299 11764 4316 11722
TIME...MOT...LOC 2201Z 145DEG 38KT 4267 11705
$$
TORNADOTOD
CI Detection Despite Low CI Values!
The upper left image below shows a low CI probability for a developing cell in northwestern Wallowa County at 2130 UTC. The CI probability was 25%. This area did not have much middle to high clouds, so the sampling was better than other areas. Still, the CI probability was relatively low.
The image below shows the Pendleton, OR radar image of the cell increasing above 35 dBZ at 2155 UTC. This gave about 25 minutes of lead time, even though the cell had a relatively low CI probability. This shows that when the middle to high clouds are not an issue, the CI product can perform well, even with low CI probabilities. JJW
The image below shows the Pendleton, OR radar image of the cell increasing above 35 dBZ at 2155 UTC. This gave about 25 minutes of lead time, even though the cell had a relatively low CI probability. This shows that when the middle to high clouds are not an issue, the CI product can perform well, even with low CI probabilities. JJW
Cell Development Near Terrain - Little Lightning/Prob Severe Detection.
The radar image from Pendleton, OR below shows a cell developing in north central Klickitat County. The cursor readout shows 57 dBZ at 2144 UTC. There was another cell that developed in nearly the same spot over the past hour.
The image below shows the topography of the area, with the cursor readout showing a local high point in that general area, with an elevation of 5,760 feet. This shows that local terrain is helping induce these cells in that same general spot. There is little to no lightning detected with this cell, and the Prob Severe is 0%. This may be due to the more sparse lightning detection in that part of the country. Still, neat to see orographic convection develop! JJW
The image below shows the topography of the area, with the cursor readout showing a local high point in that general area, with an elevation of 5,760 feet. This shows that local terrain is helping induce these cells in that same general spot. There is little to no lightning detected with this cell, and the Prob Severe is 0%. This may be due to the more sparse lightning detection in that part of the country. Still, neat to see orographic convection develop! JJW
1-Minute Satellite Imagery Where Radar Data is Poor
We are watching the Pendleton, Oregon (PDT) CWA this afternoon waiting for more thunderstorms to develop. I am finding that the 1-minute satellite imagery is useful where radar data coverage is poor, especially out west.
-BW
 |
| Watching for convection on the 1-minute satellite data out west |
 |
| Our CWA outlined in white with the radar coverage mapping. Shows a void in radar data across the southern part of our CWA. |
CI Even With Thin Middle To High Clouds - CI Is Occurring!
The CI and GOES-15 visible image in the upper right shows a cursor readout with a 15% CI probability at 2030 UTC just southwest of the Pendleton, OR CWA. This was occurring, despite some relatively thin middle to high clouds moving through the area. This would suggest that the CI value would be much higher, if the middle to high clouds were not present.
Below is the 1-minute SRSOR imagery with this developing cell at 2030 UTC. The imagery clearly showed a robust updraft developing.
The MRMS 0.5km MSL Composite Reflectivity radar image below (upper left image) at 2030 UTC showed this cell indeed had risen above the 35 dBZ threshold (46.5 dBZ in the composite reflectivity). Thus, this cell would likely have had a higher CI without the thinner middle to high clouds present. JJW
Below is the 1-minute SRSOR imagery with this developing cell at 2030 UTC. The imagery clearly showed a robust updraft developing.
The MRMS 0.5km MSL Composite Reflectivity radar image below (upper left image) at 2030 UTC showed this cell indeed had risen above the 35 dBZ threshold (46.5 dBZ in the composite reflectivity). Thus, this cell would likely have had a higher CI without the thinner middle to high clouds present. JJW
Sierra Nevada MCV
GOES SRSOR vapor channel showing distinct twist over the central Sierra's this afternoon as shown in the image animation below.
Image below shows convection associated with this feature over the central Sierra's and just east of Lake Tahoe.
Tornadotod
 | |
| GOES 14 SRSOR Water Vapor Animation |
 | |
| 2054Z Composite Reflectivity |
CI Product Stuggling With Thicker Middle To High Clouds Over Area.
The Pendleton, OR radar image below shows cells developing across the northwestern part of their CWA. The cursor readout shows a developing cell in north central Klickitat County at 2035 UTC.
The CI and GOES-15 visible imagery in the upper left shows little to no CI probabilities in that area. Interestingly, the cursor readout below shows a small pink area in the same spot as the developing cell above. The pink depicts the snow mask, so I'm not sure why the CI product thinks it is part of the snow mask. Overall, the CI product is struggling to locate these developing cells, likely due to the thick middle to high clouds moving through the area. JJW
The CI and GOES-15 visible imagery in the upper left shows little to no CI probabilities in that area. Interestingly, the cursor readout below shows a small pink area in the same spot as the developing cell above. The pink depicts the snow mask, so I'm not sure why the CI product thinks it is part of the snow mask. Overall, the CI product is struggling to locate these developing cells, likely due to the thick middle to high clouds moving through the area. JJW
Radar Coverage is a Challenging Problem Out West
Due to the varying terrain in the western U.S. there are many data gaps in radar coverage. Luckily...1-minute SRSOR Visible imagery is available and will add great value in situational awareness this afternoon.
~Lilly Miller~
 | ||
| Base Reflectivity (LEFT) and MRMS Radar Quality Index (1.0 - Best, 0.0 - Worst) (RIGHT) |
 |
| 1-minute SRSOR Visible Imagery with CI algorithm and ENI Total Lightning overlaid. |
~Lilly Miller~
Mesoscale update 2 BOI
19Z GOES LAP shows instability building through the Snake River Valley and northward into the Salmon mountains. 20Z GOES SRSOR visible imagery shows an area of expanding cumulus moving northward out of north central Nevada and expect high based convection will develop by 21Z. Broad based surface dewpoint depressions suggest more vigorous convection will pose a dry microburst wind threat and potential hail threat over northern counties where low level moisture is maximized. Will continue to monitor...
Tornadotod
 |
| 19Z GOES LAP/20Z GOES Vis |
GOES SRSOR cloud tracer
18Z GOES derived winds denote a lack of low level winds through north central NV. However GOES SRSOR visible imagery aides in tracking cumulus clouds through northern NV and gives a sense of the speed and direction of the flow in an otherwise data void area.
Tornadotod
 |
| 18Z GOES Satellite Derived Winds |
 |
| 1838-1927Z GOES SRSOR Loop (note the movement of developing cumulus over north central Nevada) |
LAP Layer PW Showing Gradient Over Pendleton, OR CWA.
The 4 panel LAP layer PW product below is showing a gradient of PW at all layers. The upper left image shows the total PW, with the cursor readout within the Pendleton, OR CWA. This gradient of PW runs from northeast to southwest across a good portion of the area. This may be an area to watch for convective development this afternoon. In addition, the upper right image shows the 700 mb to 300 mb layer PW. This will need to be watched as well, to see if the drier air to the southeast shifts into the area. This would indicate drying aloft and possibly steeper lapse rates and increased instability. JJW
LAP CAPE Showing Spots Of Data Within GFS-Dominated Sampling Area.
The upper left image below shows LAP CAPE values in spots across the Pendleton, OR CWA at 1700 UTC. The cursor readout shows spotty values ranging from about 300 J/kg to 750 J/kg. The LI values ranged from -1 to -3 as well in these spots. These were in spots that mainly had cloudy sky sampling. The GFS sampling did not show any CAPE and positive LI values, which seems to be underestimating (again).
The modified 1200 UTC sounding below from Boise, ID shows CAPE values around 860 J/kg. This was adjusted for surface and low level temperature and dew point temperature profiles around 1800 UTC in north central portions of the Pendleton, OR CWA. The 860 J/kg may be overdone somewhat, as the low levels of the sounding may need further refinement as the afternoon progresses. Still, the LAP CAPEs of 300 J/kg to 750 J/kg in the small points across the area seem reasonable, compared to the 1200 UTC Boise ID modified sounding. I would be more confident to assume that the LAP CAPE values were located across a good portion of the forecast area. JJW
The modified 1200 UTC sounding below from Boise, ID shows CAPE values around 860 J/kg. This was adjusted for surface and low level temperature and dew point temperature profiles around 1800 UTC in north central portions of the Pendleton, OR CWA. The 860 J/kg may be overdone somewhat, as the low levels of the sounding may need further refinement as the afternoon progresses. Still, the LAP CAPEs of 300 J/kg to 750 J/kg in the small points across the area seem reasonable, compared to the 1200 UTC Boise ID modified sounding. I would be more confident to assume that the LAP CAPE values were located across a good portion of the forecast area. JJW
Environment for Thunderstorm Development (PDT CWA)
Checking the environment today, it does look like we will see some scattered afternoon and evening thunderstorms.
We are seeing a lot of GFS panels in the LAP product today, but with some satellite inferred as well.
There is a swath of enhanced CAPE, LI, and PW stretching from the southwest part of the CWA around the Cascade Mountains up to the northeast corner.
It will be interesting to watch how things pan out today and if anything turns severe.
-BW
We are seeing a lot of GFS panels in the LAP product today, but with some satellite inferred as well.
There is a swath of enhanced CAPE, LI, and PW stretching from the southwest part of the CWA around the Cascade Mountains up to the northeast corner.
It will be interesting to watch how things pan out today and if anything turns severe.
-BW
Satellite Winds Showing Upper Level Diffluence
The upper level winds in the western portion of Boise's forecast area are showing some upper level diffluence. This is also where some storms are starting to fire per recent radar imagery...
~Lilly Miller~
GOES Winds Estimating 700-300mb Shear - Need More 700mb Samples.
The lower left image shows the 1-minute SRSOR imagery with the GOES winds overlaid. The cursor readout over the far north central portion of the Pendleton, OR CWA shows one sample of winds at 718 mb of 21 knots. It also shows a sample of 362 mb winds of 44 knots. This gives an approximate 700-350 mb shear of 23 knots, which is rather weak. However, sites to the southeast of that area are showing 250 mb winds in the 70-75 knot range. This would give larger shear values from 700-250mb (100 mb deeper than the sample location), assuming the 700 mb winds are similar to the sample point. The lack of sampling of 700 mb winds suggest that this assumption cannot be made. Even so, GOES wind data at 700 mb would be something to watch for as the afternoon progresses. JJW
Pre-Convective LAPS Analysis
As a large upper low swings into California...strong southerly flow is streaming into the Boise area on the upstream side of the upper trough. This flow is ushering in additional moisture but is also increasing upper level diffluence in the region. In the image below...the 12Z BOI sounding is being compared to the 12Z LAPS data (which is mostly GFS output). At 12Z, both the sounding and LAPS shows a very stable environment with positive LI's and zero CAPE.
But by 17Z...the LAPS data is showing some instability in both the CAPE and LI fields as well as an increase in Layer PW. These values coincide well with the 17Z RAP Sounding.
~Lilly Miller~
BOI Mesoscale Update
Stout sw disturbance wrapping up off the SOCAL coast late this morning. Robust jet streak working northward in largely deep meridonal flow pattern should yield convection by mid afternoon invof the northern Snake River Valley especially in light of current clearing across the area and deemed sufficient destabilization.
While GOES LAP derived PW/early morning NUCAPS pass shows limited moisture attm expect improvement through this afternoon as favorable deep southerly flow advects additional moisture north. High based convection will present a limited yet marginal hail threat. However more robust wind threat expected with fairly deep/dry subcloud layer driving effecting evaporational cooling. Will continue to monitor.
Tornadotod
While GOES LAP derived PW/early morning NUCAPS pass shows limited moisture attm expect improvement through this afternoon as favorable deep southerly flow advects additional moisture north. High based convection will present a limited yet marginal hail threat. However more robust wind threat expected with fairly deep/dry subcloud layer driving effecting evaporational cooling. Will continue to monitor.
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| 10Z BOI NUCAPS |
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| 16Z GOES LAP/Winds |
Tornadotod
Week 3 Day 4 (05 May 2016) begins
The final day of opreations for Week 3 has begun. Operations shifted to the Western US for the first time this year, with one group in Boise and the other in Pendleton. Guidance from the EFP indicates severe storms should develop across eastern Oregon this afternoon / early evening.
Wednesday, May 4, 2016
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.
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.
Week 3 Day 3 Complete
Week 3 Day 3 (May 4, 2016) of the HWT 2016 GOES-R/JPSS Spring Experiment certainly was the quietest day of this 4 week experiment thus far. Particpants worked the Miami and Memphis CWA's. The group in Miami moved to Tampa about midway through the shift. Convection stayed subsevere for both groups.
Quiet days like this, however, do have their benefits. Particpants had ample time to really interrogate each of the products, providing more detailed blog posts than is sometimes possible on the busy days.
For tomorrow, we look forward to moving to the western US for the first time this year.
Quiet days like this, however, do have their benefits. Particpants had ample time to really interrogate each of the products, providing more detailed blog posts than is sometimes possible on the busy days.
For tomorrow, we look forward to moving to the western US for the first time this year.
Overview For Wednesday, May 4, 2016
Today was a day that had weak CAPE (less than 500 J/kg) and modest deep layer shear across the Memphis CWA. A pre-frontal trough slide southward through the area and brought a broken line of showers and some thunderstorms. The storms were relatively weak and did not last too long.
The CI product seemed to pick out some cells that developed into 35 dBZ-plus echoes across portions of the Memphis CWA. The threshold for development seemed to be above 35%, which was lower than the past few days. The convection was relatively low topped, with low freezing levels, so this may have been why CI values above 35% had a good chance of developing. That being said, there were some cells that exceeded 35% that did not develop. Still, the CI product seemed to help deliniate the cells that had a good chance to develop.
The LAP layer PW and CAPE products were helpful with evaluating the environment near the showers and storms today. They gave some confidence that cells may develop south of the advancing pre-frontal trough. In addition, the gradients of the total and 700-300mb PW helped focus areas to watch for future convective development. These products were helpful.
The NUCAPS soundings, once adjusted in the low levels for realistic values, seemed to show representative CAPE and 0C/-20C level values in areas a little southeast of the Memphis area. After comparing to some 12 UTC soundings from representative areas, the NUCAPS values were useful to assess the environment ahead of the showers and storms.
JJW
The CI product seemed to pick out some cells that developed into 35 dBZ-plus echoes across portions of the Memphis CWA. The threshold for development seemed to be above 35%, which was lower than the past few days. The convection was relatively low topped, with low freezing levels, so this may have been why CI values above 35% had a good chance of developing. That being said, there were some cells that exceeded 35% that did not develop. Still, the CI product seemed to help deliniate the cells that had a good chance to develop.
The LAP layer PW and CAPE products were helpful with evaluating the environment near the showers and storms today. They gave some confidence that cells may develop south of the advancing pre-frontal trough. In addition, the gradients of the total and 700-300mb PW helped focus areas to watch for future convective development. These products were helpful.
The NUCAPS soundings, once adjusted in the low levels for realistic values, seemed to show representative CAPE and 0C/-20C level values in areas a little southeast of the Memphis area. After comparing to some 12 UTC soundings from representative areas, the NUCAPS values were useful to assess the environment ahead of the showers and storms.
JJW
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
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~
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~
Layer PW Gradients Helpful With Placement Of Storms In KY and TN.
Below is the 4 panel LAP Layer PW product at 2100 UTC. The total PW image in the upper left, and the 700-300mb layer PW in the upper right, were showing a plume of PW from eastern KY into south central TN.
The MRMS 0.5 degree reflectivity image below shows a broken line of showers and some storms from eastern KY into north central TN. This corresponded to the backside gradient of PW described above. These gradients are a good way to find more favorable areas for convective development. JJW
The MRMS 0.5 degree reflectivity image below shows a broken line of showers and some storms from eastern KY into north central TN. This corresponded to the backside gradient of PW described above. These gradients are a good way to find more favorable areas for convective development. JJW
LAP Underestimating CAPE A Bit - Still Gave A Reasonable Estimate.
The upper left image shows LAP CAPE, with the cursor readout in a small area of CAPE in clear skies in northern MS. The value was around 262 J/kg, which seemed a little low, compared to the modified NUCAPS soundings and Prob Severe model output around 400 J/kg. The CAPE values elsewhere were in the 150-300 J/kg range in the Memphis CWA. Still, it gave a reasonable idea of how much CAPE was present. Perhaps the lack of clear sky data (see upper right image) may have lead to the slight underestimate. JJW
WV/IR 1-minute Imagery Loop
Just a little loop for your enjoyment...
SRSOR 1-minute IR imagery overtop 1-min WV imagery. This allows you to see the active convection and cold cloud tops as well as the mid to upper level moisture.
~Lilly Miller~
SRSOR 1-minute IR imagery overtop 1-min WV imagery. This allows you to see the active convection and cold cloud tops as well as the mid to upper level moisture.
~Lilly Miller~
Surge of Cool, Dry Air seen in the AMV's
The CI and Severe CI algorithms had some false detects within this loop (top two panels) where convection didn't end up firing both along the convective line and southwest of the line.
~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
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
Convection struggles...
Isolated convection continues to simmer across central and eastern portions of the MEG CWA and over points east and northeast. GOES LAP PW shows the greatest concentration of low topped storms focused within richest total layer PW values near 0.90" and corresponding 900mb PW near 0.30". Given continued limited moisture expect isolated convection will continue to struggle with minimal severe threat expected through the remainder of this afternoon.
Tornadotod
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| 19Z GOES LAP PW and MRMS Composite Reflectivity |
Tornadotod
NUCAPS Plan View 497mb Temperatures - Good Snapshot of Values But Has Several Data Void Areas.
This is a plan view image of the NUCAPS 497mb temperatures, with the cursor readout showing -17.95C values, at 1800 UTC, in the middle of the Memphis CWA. There are several data void areas, so this image may not help to assess all areas for temperatures at this level. However, it does give an idea of the temperatures at this level at 1800 UTC. This could benefit the mesoscale analyst in assessing temperature profiles and the expectation for continued development of showers and a few storms. JJW
KTBW Laps versus NUCAPS Sounding
The 18Z NUCAPS Adjusted Sounding came in drier than originally thought. But taking a closer look at the LAPS Layer PW data...the drier sounding makes sense. At a clear air retrieval point bout 15 miles off of the coast of Whitney Beach, FL showed ample moisture at low levels but much drier air at mid and upper levels. The total layer PW according to LAPS was 1.7" but the NUCAPS sounding indicated a TPW value of 1.3". Drier air was noted in WV imagery so perhaps the actual PW value is somewhere in the middle.
~Lilly Wood~
~Lilly Wood~
CI Provides Lead Time on Cell Just South Of Memphis.
Below in the upper right is the CI product. The cursor readout shows a value of 58% with a cell just southeast of the city of Memphis in Shelby County at 1945 UTC.
The radar image from KNQA below shows the cell with 41 dBZ at 2003 UTC exiting far southern Shelby County. This provided about 18 minutes of lead time for the 35 dBZ-plus echo. This made sense, as the modified NUCAPS sounding (not shown) showed a little more than 400 J/kg of CAPE in that area, ahead of the pre-frontal surface trough. JJW
The radar image from KNQA below shows the cell with 41 dBZ at 2003 UTC exiting far southern Shelby County. This provided about 18 minutes of lead time for the 35 dBZ-plus echo. This made sense, as the modified NUCAPS sounding (not shown) showed a little more than 400 J/kg of CAPE in that area, ahead of the pre-frontal surface trough. JJW
GOES CI strikes again...
While waiting for convection to pop further west closer to the low level instability gradient, GOES CI provided an excellent prediction with 1915Z output indicating 65-70% probabilities over the central CWA.
21 minutes later, MRMS Composite Reflectivity echoes above 35 dBZ have developed over central portions of the CWA collocated right where GOES CI had its higher probs. Excellent!
Tornadotod
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| 1915Z GOES CI |
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| 1936 MRMS 0.5 km MSL Composite Reflectivity |
Tornadotod
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