Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 82, NWS Des Moines, IA

July 30, 20214 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jul 30, 2021, 9:52 PM CDT for 4 counties in Iowa. It was in force for 34 min. 1 report 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: Jul 30, 2021, 9:52 PM CDT (02:52 UTC)
Expired: Jul 30, 2021, 10:26 PM CDT
In force: 34 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

Counties Clarke County, IA, Decatur County, IA, Ringgold County, IA, Union County, IA

The radar

The Des Moines radar (KDMX), 95 km from the middle of the area, began a volume at 02:56 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
Jul 30, 9:57 PM CDT	HAIL 1.75	2 W Murray, IA	TRAINED SPOTTER REPORTS WIND DRIVEN GOLF BALL SIZED HAIL AND HEAVY RAINFALL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 30, 8:47 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 2.9 hours before the alert went out and 209 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2669 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 967 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 52 m²/s²
0-3 km storm-relative helicity: 279 m²/s²
Significant tornado parameter: 3.4
Supercell composite: 19.5

Open this sounding in Storm Lab

The text

As transmitted.

464 
WUUS53 KDMX 310252
SVRDMX
IAC039-053-159-175-310345-
/O.NEW.KDMX.SV.W.0082.210731T0252Z-210731T0345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
952 PM CDT Fri Jul 30 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Northwestern Decatur County in south central Iowa...
  Southeastern Union County in south central Iowa...
  Northeastern Ringgold County in south central Iowa...
  Southwestern Clarke County in south central Iowa...

* Until 1045 PM CDT.

* At 952 PM CDT, a severe thunderstorm was located 9 miles west of
  Lakeside Casino, or 10 miles west of Osceola, moving southeast at
  25 mph.

  HAZARD...60 mph wind gusts and half dollar 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
  northwestern Decatur, southeastern Union, northeastern Ringgold and
  southwestern Clarke Counties, including the following locations...
  Weldon, Thayer, Grand River, Murray, Murray Roadside Rest Area, Van
  Wert and Beaconsfield.

This includes Interstate 35 between mile markers 18 and 29.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4074 9403 4104 9409 4110 9389 4084 9368
TIME...MOT...LOC 0252Z 334DEG 22KT 4104 9398 

HAIL...1.25IN
WIND...60MPH
 
$$

Ansorge

3 follow-up statements

944 
WWUS53 KDMX 310259
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
959 PM CDT Fri Jul 30 2021

IAC039-053-159-175-310345-
/O.CON.KDMX.SV.W.0082.000000T0000Z-210731T0345Z/
Decatur IA-Union IA-Ringgold IA-Clarke IA-
959 PM CDT Fri Jul 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1045 PM CDT
FOR NORTHWESTERN DECATUR...SOUTHEASTERN UNION...NORTHEASTERN RINGGOLD
AND SOUTHWESTERN CLARKE COUNTIES...

At 958 PM CDT, a severe thunderstorm was located 8 miles west of
Lakeside Casino, or 9 miles west of Osceola, moving southeast at 25
mph.

HAZARD...60 mph wind gusts and half dollar size hail. Golf ball 
         sized hail has fallen near Murray at 957pm.

SOURCE...Trained weather spotters.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Osceola, Sun Valley Lake, Murray, Grand River, Van Wert, Weldon,
Thayer, Beaconsfield and Murray Roadside Rest Area.

This includes Interstate 35 between mile markers 18 and 29.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4074 9403 4104 9409 4110 9389 4084 9368
TIME...MOT...LOC 0258Z 334DEG 22KT 4100 9396 

HAIL...1.25IN
WIND...60MPH
 
$$

Ansorge

556 
WWUS53 KDMX 310308
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
1008 PM CDT Fri Jul 30 2021

IAC039-053-159-175-310345-
/O.CON.KDMX.SV.W.0082.000000T0000Z-210731T0345Z/
Decatur IA-Union IA-Ringgold IA-Clarke IA-
1008 PM CDT Fri Jul 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1045 PM CDT
FOR NORTHWESTERN DECATUR...SOUTHEASTERN UNION...NORTHEASTERN RINGGOLD
AND SOUTHWESTERN CLARKE COUNTIES...

At 1008 PM CDT, a severe thunderstorm was located 9 miles southwest
of Lakeside Casino, or 9 miles southwest of Osceola, moving southeast
at 25 mph.

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

SOURCE...Trained weather spotters.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Sun Valley Lake, Grand River, Van Wert and Weldon. 

This includes Interstate 35 between mile markers 18 and 29.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4074 9403 4097 9407 4104 9385 4084 9368
TIME...MOT...LOC 0308Z 334DEG 22KT 4094 9392 

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

Ansorge

861 
WWUS53 KDMX 310326
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
1026 PM CDT Fri Jul 30 2021

IAC039-053-159-175-310336-
/O.CAN.KDMX.SV.W.0082.000000T0000Z-210731T0345Z/
Decatur IA-Union IA-Ringgold IA-Clarke IA-
1026 PM CDT Fri Jul 30 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN DECATUR...
SOUTHEASTERN UNION...NORTHEASTERN RINGGOLD AND SOUTHWESTERN CLARKE
COUNTIES IS CANCELLED...
                
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 has been cancelled.

A Severe Thunderstorm Watch remains in effect until 200 AM CDT for
south central Iowa.

LAT...LON 4074 9403 4097 9407 4104 9385 4084 9368
TIME...MOT...LOC 0326Z 334DEG 22KT 4084 9385 

$$

Ansorge

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 30, 9:38 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Madison, Union	37 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2021 Every 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.