Alert archive / Iowa / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 89, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Aug 20, 2021, 9:05 PM CDT for Franklin County, Wright County, Iowa. It was in force for 55 min. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Aug 20, 2021, 9:05 PM CDT (02:05 UTC)
- Expired
- Aug 20, 2021, 10:00 PM CDT
- In force
- 55 min
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Franklin County, IA, Wright County, IA
The radar
The Des Moines radar (KDMX), 112 km from the middle of the area, began a volume at 02:04 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 20, 9:12 PM CDT | TSTM WND GST 52 | 3 N Goldfield, IA | PEAK WIND THUS FAR FROM CWOP MESONET STATION. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Minneapolis, MN (KMPX), launched 00:00Z, 2.1 hours before the alert went out and 235 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
- 395 J/kg
- Mixed-layer CIN
- -100 J/kg
- Mixed-layer LCL
- 1368 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 233 m²/s²
- 0-3 km storm-relative helicity
- 303 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 2.4
The text
As transmitted.
374
WUUS53 KDMX 210205
SVRDMX
IAC069-197-210300-
/O.NEW.KDMX.SV.W.0089.210821T0205Z-210821T0300Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
905 PM CDT Fri Aug 20 2021
The National Weather Service in Des Moines has issued a
* Severe Thunderstorm Warning for...
Wright County in north central Iowa...
Western Franklin County in north central Iowa...
* Until 1000 PM CDT.
* At 905 PM CDT, a severe thunderstorm was located over Eagle Grove,
or 8 miles west of Clarion, moving east at 40 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* This severe thunderstorm will be near...
Clarion and Elm Lake around 920 PM CDT.
Other locations in the path of this severe thunderstorm include
Belmond.
This includes Interstate 35 between mile markers 156 and 164.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4263 9338 4256 9392 4256 9397 4280 9397
4291 9349 4291 9345 4290 9345
TIME...MOT...LOC 0205Z 251DEG 36KT 4270 9388
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Cogil2 follow-up statements
182
WWUS53 KDMX 210229
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
929 PM CDT Fri Aug 20 2021
IAC069-197-210300-
/O.CON.KDMX.SV.W.0089.000000T0000Z-210821T0300Z/
Wright IA-Franklin IA-
929 PM CDT Fri Aug 20 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR WRIGHT AND WESTERN FRANKLIN COUNTIES...
At 929 PM CDT, a severe thunderstorm was located over Clarion, moving
east at 30 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Belmond.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4263 9338 4256 9392 4256 9397 4280 9397
4291 9349 4291 9345 4290 9345
TIME...MOT...LOC 0229Z 253DEG 25KT 4272 9372
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Cogil668
WWUS53 KDMX 210301
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
1001 PM CDT Fri Aug 20 2021
IAC069-197-210311-
/O.EXP.KDMX.SV.W.0089.000000T0000Z-210821T0300Z/
Wright IA-Franklin IA-
1001 PM CDT Fri Aug 20 2021
...THE SEVERE THUNDERSTORM WARNING FOR WRIGHT AND WESTERN FRANKLIN
COUNTIES HAS EXPIRED...
The severe thunderstorm which prompted the warning has weakened
slightly. Therefore, the warning has been allowed to expire. However
gusty winds and very heavy rain are still possible with this
thunderstorm.
LAT...LON 4263 9338 4256 9392 4256 9397 4280 9397
4291 9349 4291 9345 4290 9345
TIME...MOT...LOC 0301Z 251DEG 36KT 4282 9334
$$
CogilThe office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 8:03 PM CDT | Special Weather Statement | DMX | Crawford | 27 min |
| Aug 20, 8:18 PM CDT | Special Weather Statement | DMX | Hancock, Winnebago, Wright | 42 min |
| Aug 20, 9:35 PM CDT | Special Weather Statement | DMX | Guthrie | 25 min |
| Aug 20, 9:46 PM CDT | Severe Thunderstorm Warning | DMX | Hamilton, Webster, Wright | 44 min |
| Aug 20, 10:10 PM CDT | Special Weather Statement | DMX | Guthrie | 35 min |
| Aug 20, 10:42 PM CDT | Special Weather Statement | DMX | Boone | 33 min |
| Aug 21, 12:45 AM CDT | Special Weather Statement | DMX | Jasper | 45 min |
Nearby
Severe Thunderstorm Warnings in Iowa, 2021Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.