Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 112, NWS Des Moines, IA

August 30, 2021Jasper County, Marshall County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Aug 30, 2021, 11:50 PM CDT for Jasper County, Marshall County, Iowa. It was in force for 40 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 30, 2021, 11:50 PM CDT (04:50 UTC)
Expired
Aug 31, 2021, 12:30 AM CDT
In force
40 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Jasper County, IA, Marshall County, IA

The radar

The Des Moines radar (KDMX), 60 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.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 4.8 hours before the alert went out and 216 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.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2021-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2021-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -4 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1670 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
63 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

530 
WUUS53 KDMX 310450
SVRDMX
IAC099-127-310530-
/O.NEW.KDMX.SV.W.0112.210831T0450Z-210831T0530Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
1150 PM CDT Mon Aug 30 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Marshall County in central Iowa...
  Northeastern Jasper County in central Iowa...

* Until 1230 AM CDT.

* At 1150 PM CDT, a severe thunderstorm was located near State
  Center, or 11 miles southwest of Marshalltown, moving east at 40
  mph.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect 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 4186 9323 4195 9323 4221 9314 4217 9279
      4171 9279
TIME...MOT...LOC 0450Z 292DEG 33KT 4195 9311 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

REV
2 follow-up statements
389 
WWUS53 KDMX 310521
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
1221 AM CDT Tue Aug 31 2021

IAC099-127-310530-
/O.CON.KDMX.SV.W.0112.000000T0000Z-210831T0530Z/
Marshall IA-Jasper IA-
1221 AM CDT Tue Aug 31 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1230 AM CDT
FOR MARSHALL AND NORTHEASTERN JASPER COUNTIES...

At 1221 AM CDT, a severe thunderstorm was located 9 miles south of
Marshalltown, moving east at 25 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Marshalltown, State Center, Rock Creek Lake, Melbourne, Gilman,
Albion, Rhodes, Liscomb, Laurel, Haverhill, Oakland Acres, Clemons,
Ferguson, Green Mountain, Marshalltown Municipal Airport and Rock
Creek State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4186 9323 4195 9323 4221 9314 4217 9279
      4171 9279
TIME...MOT...LOC 0521Z 291DEG 24KT 4190 9295 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

REV
554 
WWUS53 KDMX 310529 RRA
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
1229 AM CDT Tue Aug 31 2021

IAC099-127-310539-
/O.EXP.KDMX.SV.W.0112.000000T0000Z-210831T0530Z/
Marshall IA-Jasper IA-
1229 AM CDT Tue Aug 31 2021

...THE SEVERE THUNDERSTORM WARNING FOR MARSHALL AND NORTHEASTERN
JASPER COUNTIES WILL EXPIRE AT 1230 AM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with this thunderstorm.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Des Moines .

LAT...LON 4186 9323 4195 9323 4221 9314 4217 9279
      4171 9279
TIME...MOT...LOC 0529Z 292DEG 33KT 4187 9287 

$$

REV

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 30, 9:58 PM CDTSevere Thunderstorm WarningDMXCarroll, Crawford, Sac62 min
Aug 30, 10:50 PM CDTSevere Thunderstorm WarningDMXCarroll, Crawford55 min
Aug 30, 10:58 PM CDTSevere Thunderstorm WarningDMXAudubon, Carroll, Crawford, Greene, Guthrie62 min
Aug 30, 11:29 PM CDTSevere Thunderstorm WarningDMXBoone, Dallas, Marshall, Polk, Story46 min
Aug 30, 11:54 PM CDTSevere Thunderstorm WarningDMXJasper, Madison, Marion, Polk, Warren36 min
Aug 31, 12:07 AM CDTSevere Thunderstorm WarningDMXAdair, Audubon, Cass, Guthrie38 min
Aug 31, 12:35 AM CDTSpecial Weather StatementDMXClarke, Lucas, Madison, Marion, Union, Warren70 min
Aug 31, 9:16 AM CDTAreal Flood WarningDMXBlack Hawk2 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.