Alert archive / Iowa / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 113, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Aug 30, 2021, 11:54 PM CDT for 5 counties in Iowa. It was in force for 36 min. 6 reports 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 30, 2021, 11:54 PM CDT (04:54 UTC)
- Expired
- Aug 31, 2021, 12:30 AM CDT
- In force
- 36 min
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Jasper County, IA, Madison County, IA, Marion County, IA, Polk County, IA, Warren County, IA
The radar
The Des Moines radar (KDMX), 38 km from the middle of the area, began a volume at 05:08 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 30, 11:56 PM CDT | TSTM WND DMG | 1 Ene Des Moines, IA | 12 INCH DIAMETER TREE LIMB FELL ON A POWER LINE, WHICH CAUSED A HOUSE FIRE. MULTIPLE 5 TO 6 INCH DIAMETER BRANCHES DOWN IN THE AREA ALSO. TIME ESTIMATED. |
| Aug 30, 11:57 PM CDT | TSTM WND DMG | 1 Ssw Des Moines, IA | TREE DOWN, WIRES DOWN. TIME ESTIMATED FROM KOAX RADAR. |
| Aug 30, 11:58 PM CDT | TSTM WND GST 59 | Des Moines Int Airport, IA | CORRECTS PREVIOUS TSTM WND GST REPORT FROM DES MOINES INT AIRPORT (DSM) FOR INCORRECT TIME. |
| Aug 31, 12:09 AM CDT | TSTM WND GST 54 | 1 Nne Norwalk, IA | PERSONAL WEATHER STATION KIANORWA29. |
| Aug 31, 12:17 AM CDT | TSTM WND DMG | 1 Ese Windsor Heights, IA | WIRES DOWN NEAR 55TH AND UNIVERSITY. |
| Aug 31, 12:29 AM CDT | TSTM WND GST 51 | 4 S Spring Hill, IA | PERSONAL WEATHER STATION KIAINDIA24. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 4.9 hours before the alert went out and 244 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
- 1443 J/kg
- Mixed-layer CIN
- -31 J/kg
- Mixed-layer LCL
- 1305 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 4 m²/s²
- 0-3 km storm-relative helicity
- 143 m²/s²
- Significant tornado parameter
- 0.3
- Supercell composite
- 3.5
The text
As transmitted.
536
WUUS53 KDMX 310454
SVRDMX
IAC099-121-125-153-181-310530-
/O.NEW.KDMX.SV.W.0113.210831T0454Z-210831T0530Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
1154 PM CDT Mon Aug 30 2021
The National Weather Service in Des Moines has issued a
* Severe Thunderstorm Warning for...
Southeastern Polk County in central Iowa...
Northeastern Madison County in south central Iowa...
Northwestern Marion County in south central Iowa...
Jasper County in central Iowa...
Warren County in south central Iowa...
* Until 1230 AM CDT.
* At 1153 PM CDT, severe thunderstorms were located along a line
extending from near State Center to near Norwalk, moving southeast
at 50 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.
* Severe thunderstorms will be near...
Baxter around 1200 AM CDT.
Indianola around 1205 AM CDT.
Other locations in the path of these severe thunderstorms include
Rock Creek Lake.
This includes the following highways...
Interstate 35 between mile markers 59 and 69, and between mile
markers 87 and 89.
Interstate 80 between mile markers 135 and 177.
Interstate 235 between mile markers 4 and 14.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4116 9341 4116 9346 4117 9347 4146 9389
4151 9380 4153 9379 4186 9333 4186 9316
4173 9277
TIME...MOT...LOC 0453Z 308DEG 45KT 4195 9315 4143 9374
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
REV2 follow-up statements
638
WWUS53 KDMX 310519
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
1219 AM CDT Tue Aug 31 2021
IAC099-121-125-153-181-310530-
/O.CON.KDMX.SV.W.0113.000000T0000Z-210831T0530Z/
Polk IA-Madison IA-Marion IA-Jasper IA-Warren IA-
1219 AM CDT Tue Aug 31 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1230 AM CDT
FOR SOUTHEASTERN POLK...NORTHEASTERN MADISON...NORTHWESTERN MARION...
JASPER AND WARREN COUNTIES...
At 1219 AM CDT, severe thunderstorms were located along a line
extending from 6 miles northeast of Baxter to near Indianola, moving
southeast at 35 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Rock Creek Lake.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4116 9341 4116 9346 4117 9347 4146 9389
4151 9380 4153 9379 4186 9333 4186 9316
4173 9277
TIME...MOT...LOC 0519Z 307DEG 29KT 4187 9304 4136 9363
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
REV444
WWUS53 KDMX 310529
SVSDMX
Severe Weather Statement
National Weather Service Des Moines IA
1229 AM CDT Tue Aug 31 2021
IAC099-121-125-153-181-310538-
/O.EXP.KDMX.SV.W.0113.000000T0000Z-210831T0530Z/
Polk IA-Madison IA-Marion IA-Jasper IA-Warren IA-
1229 AM CDT Tue Aug 31 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN POLK...
NORTHEASTERN MADISON...NORTHWESTERN MARION...JASPER AND WARREN
COUNTIES WILL EXPIRE AT 1230 AM CDT...
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire. However gusty
winds to 50 mph and heavy rain are still possible with these
thunderstorms.
To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Des Moines .
LAT...LON 4116 9341 4116 9346 4117 9347 4146 9389
4151 9380 4153 9379 4186 9333 4186 9316
4173 9277
TIME...MOT...LOC 0528Z 308DEG 45KT 4180 9292 4129 9351
$$
REVThe office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 30, 9:58 PM CDT | Severe Thunderstorm Warning | DMX | Carroll, Crawford, Sac | 62 min |
| Aug 30, 10:50 PM CDT | Severe Thunderstorm Warning | DMX | Carroll, Crawford | 55 min |
| Aug 30, 10:58 PM CDT | Severe Thunderstorm Warning | DMX | Audubon, Carroll, Crawford, Greene, Guthrie | 62 min |
| Aug 30, 11:29 PM CDT | Severe Thunderstorm Warning | DMX | Boone, Dallas, Marshall, Polk, Story | 46 min |
| Aug 30, 11:50 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Marshall | 40 min |
| Aug 31, 12:07 AM CDT | Severe Thunderstorm Warning | DMX | Adair, Audubon, Cass, Guthrie | 38 min |
| Aug 31, 12:35 AM CDT | Special Weather Statement | DMX | Clarke, Lucas, Madison, Marion, Union, Warren | 70 min |
| Aug 31, 9:16 AM CDT | Areal Flood Warning | DMX | Black Hawk | 2 hr |
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.