Inthecards/wacha
Wednesday, June 10, 2015
Discussion for LOT
Boundary positioned today over LOT CWA. Small amount of CIN remaining but Convective temps are expected to be reached shortly across much of the area. Goes_R parameters are showing CAPES in excess of 3000 across the western portions of the CWA. These 18Z values are showing somewhat less than what we are currently seeing on the SPC Meso-analysis, but this may be due to the sharp increase in capes over the last several hours over 2000 increase in some areas. Other indicies (LI, TT and showalter) are all sufficient to support severe weather…effective bulk shear is also about 25-30KT. Given the instability and shear the main threats will be for damaging winds and hail.
Inthecards/wacha
Inthecards/wacha
Cirrus obscuring LAP Algorithm CAPE
One thing we quickly noticed was that the CAPE values from the LAP algorithm were nowhere near the values represented on the mesoanalysis page. Part of the problem seemed to be due to the obscuring cirrus over 2/3rds of the forecast area. Attached is the latest image and a loop of the CAPE retreating east as the high clouds move in.
Tuesday, June 9, 2015
Daily Summary: Week 5, Day 2 (June 9, 2015)
On the second day of week 5, forecasters began operations in the Boston, Albany, and Duluth CWA's. As activity quieted down on the east coast, the Albany group transitioned to Rapid City, and the Boston group to Minneapolis. The day's most interesting convective activity was situated well away from any LMA, so the PGLM total lightning tools were not evaluated, unfortunately.
- Bill Line, SPC/HWT Satellite Liaison
GOES-R LAP
- PW matched with SPC mesoanalysis.
- In rapid city, higher values to east with a PW gradient in place, cell was locked on topo, used high res topo map. Storm was running out of moisture.
- Storms moving into drier air died off, could not go any further west where moisture was lacking
NUCAPS
- Compared to Albany 18z sounding, values of cape looked fairly on point
- For rapid city, 19z pass, spc meso showed 5000 cape, ncuaps showed that much as well.
GOES-R CI
- CI was a good indicator 30-45 min in advance
- In SW SD, black hills, it showed 90, then next frame storm went up
- We found it more useful in boston then minny, it did a good job east of Albany, into Vermont, showed convection would continue to develop.
- I think a ci to severe would be more helpful for me in the wfo
- Algorithm shut off from 30s to nothing. … this was because cloud type likely changed, from cu to more stratiform. So algorithm shuts off once we have stratiform
- To discern what the convective mode will be would be helpful
- When we switched to night, ringing of obs on thin cirrus
- Any diagnostic info under the hood that might be useful to see, in readout, because the probs themselves are such a black box
ProbSevere
- Switched from boston to minny, we had no SA, first thing that popped up was a 90+%, so we brought up warngen right away. Gave us enough confidence to go ahead and warn, then we can go and get caught up
- Cell over SD, started as 90+, then dropped to 30 briefly, then back to 90, issued warning
- Highest in Duluth was 55, gave us confirmation that what we were seeing was sub severe
- In boston, low probs, telling us what wasn’t significant, which was most storms yesterday
- In SD, with discrete cells, we used it to monitor mature evolution
- We had a case like in the training, 1.5 hr for first report, used prob severe to issue, no reports initially, but finally reports later
- Time series of probabilities would be helpful to see
SRSOR and 1-min OTD
- Looked at it in Boston, to me it’s a base data product, like radar.
- Confirmed to me what I was thinking would happen, southeast coast of New England, marine stratus moving inland, cooling overwhelmed se New England, could see really well with 1-min imagery, movement of stratus and different cloud forms
- It’s in our office now, I am sad when the sector isn’t over our cwa
Lightning jump
- When we were thinking of reissuing, it jumped, giving us confidence in our decision
- We saw LJ’s concurrent with increases in probsevere,
- It might be useful to have more info available, such as the actual amount of lightning
- Bill Line, SPC/HWT Satellite Liaison
GOES-R LAP
- PW matched with SPC mesoanalysis.
- In rapid city, higher values to east with a PW gradient in place, cell was locked on topo, used high res topo map. Storm was running out of moisture.
- Storms moving into drier air died off, could not go any further west where moisture was lacking
NUCAPS
- Compared to Albany 18z sounding, values of cape looked fairly on point
- For rapid city, 19z pass, spc meso showed 5000 cape, ncuaps showed that much as well.
GOES-R CI
- CI was a good indicator 30-45 min in advance
- In SW SD, black hills, it showed 90, then next frame storm went up
- We found it more useful in boston then minny, it did a good job east of Albany, into Vermont, showed convection would continue to develop.
- I think a ci to severe would be more helpful for me in the wfo
- Algorithm shut off from 30s to nothing. … this was because cloud type likely changed, from cu to more stratiform. So algorithm shuts off once we have stratiform
- To discern what the convective mode will be would be helpful
- When we switched to night, ringing of obs on thin cirrus
- Any diagnostic info under the hood that might be useful to see, in readout, because the probs themselves are such a black box
ProbSevere
- Switched from boston to minny, we had no SA, first thing that popped up was a 90+%, so we brought up warngen right away. Gave us enough confidence to go ahead and warn, then we can go and get caught up
- Cell over SD, started as 90+, then dropped to 30 briefly, then back to 90, issued warning
- Highest in Duluth was 55, gave us confirmation that what we were seeing was sub severe
- In boston, low probs, telling us what wasn’t significant, which was most storms yesterday
- In SD, with discrete cells, we used it to monitor mature evolution
- We had a case like in the training, 1.5 hr for first report, used prob severe to issue, no reports initially, but finally reports later
- Time series of probabilities would be helpful to see
SRSOR and 1-min OTD
- Looked at it in Boston, to me it’s a base data product, like radar.
- Confirmed to me what I was thinking would happen, southeast coast of New England, marine stratus moving inland, cooling overwhelmed se New England, could see really well with 1-min imagery, movement of stratus and different cloud forms
- It’s in our office now, I am sad when the sector isn’t over our cwa
Lightning jump
- When we were thinking of reissuing, it jumped, giving us confidence in our decision
- We saw LJ’s concurrent with increases in probsevere,
- It might be useful to have more info available, such as the actual amount of lightning
TBSS and Golf Balls
Very pronounced TBSS on a cell just north of KMSP. Storm has produced golf ball size hail at 713 CST. NOAA/CIMMS Severe Prob near 90%. Not crazy about the color bar right over the top of the base data color bar. Maybe it could go just below? MrSnow.
CI Day vs Night
Perfect example across SD how the CI model has a tough time when switching from day (1st image) to night mode (2nd image). The outer edges of the storms are assigned a low percentage (~20%).
Renville Co Storm MPX
An increase in the CIMSS prob severe gave us higher confidence to issue this warning for this storm over you can see a jump in the lightning also near the time the prob severe increased it’s prob.
10 Sig Jump!
We spotted a 10 sigma lightning jump with the cell heading into Lyman Co, SD! This is probably the highest value we’ve spotted so far. There were only 2 CG strikes though. Still looks nice on reflectivity.
-BT
-BT
Storms Finally Form in Northeastern MN
Scattered showers and storms finally formed in Northeastern MN late this afternoon. However, with just marginal instability storms have remained below severe limits despite excellent deep layer shear in the 40-50 kt range. As mentioned in a previous post CI indicated a line/cluster of showers and storms was likely to develop. As storms develop the CIMSS Prob severe model showed most storms having only a small chance of being severe, which has worked out great today (see images below for radar/prob svr at around 2330Z and CI near 22Z).
-Wacha
-Wacha
Severe Left Moving split and Lightning goes to zero
Curious left mover from a second storm split produced 64 mph winds at 610 pm. Warning was based on 50+ dBZ to 36Kft. Lightning has waned to near zero, but reflectivity remains 65 to 70 dBZ. The right moving cells seem to be dying out. The initial warning was based on a 90% prob severe according to the NOAA/CIMSS model. This was extremely useful since we had little situational awareness since we just started but had enough trust in it and a quick glance at the radar confirmed it was probably on to something. Helped give us a nearly 20 minute lead time. MrSnow/itsinthecards
Interesting Observation
While looking at the CAPE and PWAT trends, we notices the storm development in SD matches almost exactly with the leading edge of the gradient ahead of the approaching cold front.
The exact CAPE values were about twice as much as the LAP analysis, but the overall pattern matched well. The NUCAPS altered sounding (adding low level moisture) brought the CAPE closer to expected values.
-BT
The exact CAPE values were about twice as much as the LAP analysis, but the overall pattern matched well. The NUCAPS altered sounding (adding low level moisture) brought the CAPE closer to expected values.
-BT
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