Alert archive / Iowa / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 44, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Jun 20, 2021, 7:17 PM CDT for Black Hawk County, Tama County, Iowa. It was in force for 43 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
- Jun 20, 2021, 7:17 PM CDT (00:17 UTC)
- Expired
- Jun 20, 2021, 8:00 PM CDT
- In force
- 43 min
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Hail
- 0.88 in
- Wind
- 60.0 mph
Counties Black Hawk County, IA, Tama County, IA
The radar
The Des Moines radar (KDMX), 140 km from the middle of the area, began a volume at 00:19 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 |
|---|---|---|---|
| Jun 20, 1:42 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Davenport, (KDVN), launched 00:00Z, 0.3 hours before the alert went out and 167 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
- 1058 J/kg
- Mixed-layer CIN
- -19 J/kg
- Mixed-layer LCL
- 1009 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 174 m²/s²
- 0-3 km storm-relative helicity
- 230 m²/s²
- Significant tornado parameter
- 1.4
- Supercell composite
- 7.8
The text
As transmitted.
460
WUUS53 KDMX 210017
SVRDMX
IAC013-171-210100-
/O.NEW.KDMX.SV.W.0044.210621T0017Z-210621T0100Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
717 PM CDT Sun Jun 20 2021
The National Weather Service in Des Moines has issued a
* Severe Thunderstorm Warning for...
Black Hawk County in northeastern Iowa...
Northeastern Tama County in central Iowa...
* Until 800 PM CDT.
* At 716 PM CDT, a severe thunderstorm was located near Evansdale, or
7 miles southeast of Waterloo, moving east at 40 mph.
HAZARD...60 mph wind gusts and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* This severe thunderstorm will be near...
La Porte City around 725 PM CDT.
Jesup around 730 PM CDT.
This includes Interstate 380 between mile markers 57 and 73.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4237 9207 4230 9215 4230 9230 4217 9230
4214 9234 4230 9257 4230 9253 4244 9253
4260 9226 4259 9208 4247 9208 4247 9206
TIME...MOT...LOC 0016Z 281DEG 34KT 4240 9228
HAIL...0.88IN
WIND...60MPH
$$
REV2 follow-up statements
328
WWUS53 KDMX 210027
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
727 PM CDT Sun Jun 20 2021
IAC013-171-210100-
/O.CON.KDMX.SV.W.0044.000000T0000Z-210621T0100Z/
Black Hawk IA-Tama IA-
727 PM CDT Sun Jun 20 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM CDT
FOR SOUTHERN BLACK HAWK AND NORTHEASTERN TAMA COUNTIES...
At 727 PM CDT, a severe thunderstorm was located near La Porte City,
or 13 miles southeast of Waterloo, moving east at 40 mph.
HAZARD...60 mph wind gusts and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
This severe thunderstorm will remain over mainly rural areas of
southern Black Hawk and northeastern Tama Counties, including the
following locations... Raymond, Tf Clark State Park, Washburn,
Gilbertville and Dunkerton.
This includes Interstate 380 between mile markers 57 and 73.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4237 9207 4230 9215 4230 9230 4217 9230
4214 9234 4230 9257 4230 9253 4237 9253
4258 9212 4259 9208 4247 9208 4247 9206
TIME...MOT...LOC 0027Z 281DEG 34KT 4238 9214
HAIL...0.88IN
WIND...60MPH
$$
REV829
WWUS53 KDMX 210100
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
800 PM CDT Sun Jun 20 2021
IAC013-171-210110-
/O.EXP.KDMX.SV.W.0044.000000T0000Z-210621T0100Z/
Black Hawk IA-Tama IA-
800 PM CDT Sun Jun 20 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN BLACK HAWK AND
NORTHEASTERN TAMA COUNTIES HAS EXPIRED...
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been allowed to expire. However gusty
winds are still possible with this thunderstorm.
A Severe Thunderstorm Watch remains in effect until 900 PM CDT for
central and northeastern Iowa.
LAT...LON 4237 9207 4230 9215 4230 9230 4217 9230
4214 9234 4230 9257 4230 9253 4237 9253
4258 9212 4259 9208 4247 9208 4247 9206
TIME...MOT...LOC 0100Z 281DEG 34KT 4232 9173
$$
REVThe office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 20, 7:59 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Poweshiek, Tama | 20 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.