Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 6, NWS Des Moines, IA

May 25, 20214 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 25, 2021, 11:53 PM CDT for 4 counties in Iowa. It was in force for 31 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
May 25, 2021, 11:53 PM CDT (04:53 UTC)
Expired
May 26, 2021, 12:24 AM CDT
In force
31 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Jasper County, IA, Marion County, IA, Polk County, IA, Warren County, IA

The radar

The Des Moines radar (KDMX), 30 km from the middle of the area, began a volume at 04:54 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

Omaha, NE (KOAX), launched 00:00Z, 4.9 hours before the alert went out and 243 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, Omaha, NE at 00:00Z on 2021-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 228 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 2021-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 square meters per square second.1939587897Sfc1 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
228 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
2355 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

921 
WUUS53 KDMX 260453
SVRDMX
IAC099-125-153-181-260545-
/O.NEW.KDMX.SV.W.0006.210526T0453Z-210526T0545Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
1153 PM CDT Tue May 25 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Southeastern Polk County in central Iowa...
  Northwestern Marion County in south central Iowa...
  Southwestern Jasper County in central Iowa...
  Northeastern Warren County in south central Iowa...

* Until 1245 AM CDT.

* At 1153 PM CDT, a severe thunderstorm was located over Pleasant
  Hill, moving east at 15 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
  southeastern Polk, northwestern Marion, southwestern Jasper and
  northeastern Warren Counties, including the following locations...
  Runnells, Swan and Hartford.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4152 9361 4161 9356 4161 9329 4141 9329
TIME...MOT...LOC 0453Z 290DEG 13KT 4155 9350 

HAIL...1.00IN
WIND...60MPH
 
$$

REV
2 follow-up statements
981 
WWUS53 KDMX 260502
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
1202 AM CDT Wed May 26 2021

IAC099-125-153-181-260545-
/O.CON.KDMX.SV.W.0006.000000T0000Z-210526T0545Z/
Polk IA-Marion IA-Jasper IA-Warren IA-
1202 AM CDT Wed May 26 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1245 AM CDT
FOR SOUTHEASTERN POLK...NORTHWESTERN MARION...SOUTHWESTERN JASPER AND
NORTHEASTERN WARREN COUNTIES...

At 1202 AM CDT, a severe thunderstorm was located over Carlisle, or
over Pleasant Hill, moving east at 15 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...
Des Moines, Pleasant Hill, Carlisle, Hartford, Runnells and Swan. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4150 9355 4159 9353 4161 9329 4141 9329
TIME...MOT...LOC 0502Z 290DEG 13KT 4154 9346 

HAIL...1.00IN
WIND...60MPH
 
$$

REV
494 
WWUS53 KDMX 260524
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
1224 AM CDT Wed May 26 2021

IAC099-125-153-181-260534-
/O.CAN.KDMX.SV.W.0006.000000T0000Z-210526T0545Z/
Polk IA-Marion IA-Jasper IA-Warren IA-
1224 AM CDT Wed May 26 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN POLK...
NORTHWESTERN MARION...SOUTHWESTERN JASPER AND NORTHEASTERN WARREN
COUNTIES IS CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has
been cancelled.  However gusty winds and heavy rain are still
possible with this thunderstorm.

LAT...LON 4150 9355 4159 9353 4161 9329 4141 9329
TIME...MOT...LOC 0523Z 290DEG 13KT 4151 9336 

$$

Cogil

The office that day

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

IssuedProductOfficeCountiesLasted
May 25, 7:05 PM CDTSevere Thunderstorm WarningDMXBoone, Dallas, Greene, Guthrie40 min
May 25, 11:14 PM CDTSpecial Weather StatementDMXAdair, Madison46 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.