Alert archive / Iowa / Mesoscale Discussions in 2021
Mesoscale Discussion 1936
The Storm Prediction Center issued this mesoscale discussion at Nov 10, 2021, 3:46 PM CST for 14 counties in Iowa; Harrison County, Mercer County, Missouri. It was in force for 119 min.
The area
The outline as issued.
The facts
- Issued
- Nov 10, 2021, 3:46 PM CST (21:46 UTC)
- Expired
- Nov 10, 2021, 5:45 PM CST
- In force
- 119 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 546
Counties Boone County, IA, Clarke County, IA, Dallas County, IA, Decatur County, IA, Jasper County, IA, Lucas County, IA, Madison County, IA, Marion County, IA, Polk County, IA, Ringgold County, IA, Story County, IA, Union County, IA, Warren County, IA, Wayne County, IA, Harrison County, MO, Mercer County, MO
The radar
The Des Moines radar (KDMX), 59 km from the middle of the area, began a volume at 21:45 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 9.8 hours before the alert went out and 215 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 684 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km storm-relative helicity
- 133 m²/s²
- 0-3 km storm-relative helicity
- 182 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
273
ACUS11 KWNS 102146
SWOMCD
SPC MCD 102146
IAZ000-MOZ000-102345-
Mesoscale Discussion 1936
NWS Storm Prediction Center Norman OK
0346 PM CST Wed Nov 10 2021
Areas affected...northwestern Missouri and south-central Iowa
Concerning...Severe Thunderstorm Watch 546...
Valid 102146Z - 102345Z
The severe weather threat for Severe Thunderstorm Watch 546
continues.
SUMMARY...Strong wind gusts remain possible this afternoon, but a
downstream Watch is not currently anticipated.
DISCUSSION...A line of storms that was previously surface-based and
producing locally strong to damaging wind gusts continues advancing
northeastward at over 40 knots into a less favorable environment
where lower/middle 50s dewpoints are resulting in only weak
instability (MLCAPE less than 500 J/kg). While somewhat favorable
deep-layer shear of 30 to 40 knots continues to support modest
organization of the line and the potential for strong/damaging wind
gusts, the increasingly stable boundary-layer conditions should
continue to limit the severe threat with northeastward extent.
Therefore, a downstream Watch is not currently anticipated.
..Weinman/Hart.. 11/10/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DMX...EAX...
LAT...LON 41429448 40699433 40219391 40299352 41489271 42049306
42079394 41429448SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 10, 1:55 PM CST | Severe Thunderstorm Watch | SPC | Adams, Decatur, Ringgold, Taylor, Union | 6 hr |
| Nov 10, 10:53 AM CST | Mesoscale Discussion | SPC | Atchison, Holt | 2 hr |
| Nov 10, 5:29 PM CST | Mesoscale Discussion | SPC | Bates, Buchanan, Caldwell, Cass, Clay, Clinton and 10 more | 2 hr |
Nearby
Mesoscale Discussions in Iowa, 2021Mesoscale Discussions in Missouri, 2021Every mesoscale discussion in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.