Alert archive / Iowa / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 86, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Aug 10, 2021, 2:14 PM CDT for Black Hawk County, Bremer County, Iowa. It was in force for 46 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Aug 10, 2021, 2:14 PM CDT (19:14 UTC)
- Expired
- Aug 10, 2021, 3:00 PM CDT
- In force
- 46 min
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Black Hawk County, IA, Bremer County, IA
The radar
The La Crosse radar (KARX), 150 km from the middle of the area, began a volume at 19:15 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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 10, 2:08 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Davenport, (KDVN), launched 12:00Z, 7.2 hours before the alert went out and 187 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
- 3755 J/kg
- Mixed-layer CIN
- -67 J/kg
- Mixed-layer LCL
- 819 m above ground
- 0-6 km bulk shear
- 12 kt
- 0-1 km storm-relative helicity
- -37 m²/s²
- 0-3 km storm-relative helicity
- 4 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
488
WUUS53 KDMX 101914
SVRDMX
IAC013-017-102000-
/O.NEW.KDMX.SV.W.0086.210810T1914Z-210810T2000Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
214 PM CDT Tue Aug 10 2021
The National Weather Service in Des Moines has issued a
* Severe Thunderstorm Warning for...
Northeastern Black Hawk County in northeastern Iowa...
Eastern Bremer County in northeastern Iowa...
* Until 300 PM CDT.
* At 214 PM CDT, a severe thunderstorm was located near Waverly,
moving east at 35 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Emergency Management. Half to one inch hail has been
reported north of Waverly.
IMPACT...Hail damage to vehicles is expected. Expect wind damage
to roofs, siding, and trees.
* This severe thunderstorm will be near...
Tripoli around 230 PM CDT.
Other locations in the path of this severe thunderstorm include
Sumner.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4257 9232 4291 9236 4291 9208 4258 9208
TIME...MOT...LOC 1914Z 252DEG 29KT 4273 9240
HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Krull2 follow-up statements
583
WWUS53 KDMX 101945
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
245 PM CDT Tue Aug 10 2021
IAC013-017-102000-
/O.CON.KDMX.SV.W.0086.000000T0000Z-210810T2000Z/
Black Hawk IA-Bremer IA-
245 PM CDT Tue Aug 10 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM CDT
FOR NORTHEASTERN BLACK HAWK AND EASTERN BREMER COUNTIES...
At 244 PM CDT, a severe thunderstorm was located near Fairbank, or 10
miles west of Oelwein, moving east at 30 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
This severe thunderstorm will remain over mainly rural areas of
northeastern Black Hawk and eastern Bremer Counties.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4258 9219 4291 9222 4291 9208 4258 9208
TIME...MOT...LOC 1944Z 250DEG 27KT 4266 9211
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Krull273
WWUS53 KDMX 101954
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
254 PM CDT Tue Aug 10 2021
IAC013-017-102004-
/O.EXP.KDMX.SV.W.0086.000000T0000Z-210810T2000Z/
Black Hawk IA-Bremer IA-
254 PM CDT Tue Aug 10 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN BLACK HAWK AND
EASTERN BREMER COUNTIES WILL EXPIRE AT 300 PM CDT...
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.
A Severe Thunderstorm Watch remains in effect until 800 PM CDT for
northeastern Iowa.
LAT...LON 4258 9219 4291 9222 4291 9208 4258 9208
TIME...MOT...LOC 1954Z 252DEG 29KT 4268 9201
$$
KrullThe office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 10, 12:50 PM CDT | Severe Thunderstorm Warning | DMX | Clarke | 25 min |
| Aug 10, 12:56 PM CDT | Heat Advisory | DMX | Adair, Adams, Appanoose, Audubon, Cass, Clarke and 18 more | 30 hr |
| Aug 10, 1:48 PM CDT | Severe Thunderstorm Warning | DMX | Black Hawk, Bremer, Butler | 42 min |
| Aug 10, 2:57 PM CDT | Severe Thunderstorm Warning | DMX | Black Hawk | 18 min |
| Aug 10, 3:00 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Marshall, Poweshiek, Tama | 60 min |
| Aug 10, 3:59 PM CDT | Special Weather Statement | DMX | Tama | 46 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.