Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 103, NWS Des Moines, IA

August 26, 2021Emmet County, Palo Alto County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Aug 26, 2021, 11:42 PM CDT for Emmet County, Palo Alto County, Iowa. It was in force for 33 min. 4 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 26, 2021, 11:42 PM CDT (04:42 UTC)
Expired: Aug 27, 2021, 12:15 AM CDT
In force: 33 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Emmet County, IA, Palo Alto County, IA

The radar

The Sioux Falls radar (KFSD), 171 km from the middle of the area, began a volume at 04:44 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 26, 11:42 PM CDT	TSTM WND GST 55	4 E Wallingford, IA	REPORT VIA KICD.
Aug 26, 11:42 PM CDT	HAIL 0.88	4 E Wallingford, IA	REPORT VIA KICD.
Aug 26, 11:54 PM CDT	TSTM WND DMG	1 N Graettinger, IA	LARGE TREES DOWN. DELAYED REPORT, TIME ESTIMATED VIA RADAR.
Aug 27, 12:03 AM CDT	TSTM WND DMG	2 E Graettinger, IA	LARGE TREES REPORTED DOWN. DELAYED REPORT, TIME ESTIMATED VIA RADAR.

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

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 4.7 hours before the alert went out and 184 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 792 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 393 m²/s²
0-3 km storm-relative helicity: 392 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

094 
WUUS53 KDMX 270442
SVRDMX
IAC063-147-270515-
/O.NEW.KDMX.SV.W.0103.210827T0442Z-210827T0515Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
1142 PM CDT Thu Aug 26 2021

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Emmet County in northwestern Iowa...
  Northern Palo Alto County in northwestern Iowa...

* Until 1215 AM CDT.

* At 1142 PM CDT, a severe thunderstorm was located over Swan Lake,
  or 10 miles east of Estherville, moving east at 10 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
  Emmet and northern Palo Alto Counties, including the following
  locations... Armstrong, Okamanpedan State Park, Wolden County Park,
  Ringsted, Graettinger, Dolliver, Fort Defiance State Park,
  Wallingford, Estherville Municipal Airport and Lost Island Lake
  State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4350 9444 4316 9444 4316 9491 4350 9491
TIME...MOT...LOC 0442Z 248DEG 8KT 4335 9463 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Krull

2 follow-up statements

838 
WWUS53 KDMX 270500
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
1200 AM CDT Fri Aug 27 2021

IAC063-147-270515-
/O.CON.KDMX.SV.W.0103.000000T0000Z-210827T0515Z/
Emmet IA-Palo Alto IA-
1200 AM CDT Fri Aug 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1215 AM CDT
FOR EMMET AND NORTHERN PALO ALTO COUNTIES...

At 1159 PM CDT, a severe thunderstorm was located near Swan Lake, or
13 miles east of Estherville, moving east at 10 mph.

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

SOURCE...Radar indicated. Nickel size hail has been reported with 
         this storm. Quarter size hail is possible.

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

Locations impacted include...
Estherville, Okamanpedan Lake, Iowa Lake, Swan Lake, Ingham Lake,
High Lake, Five Island Lake, Armstrong, Graettinger, Ringsted,
Wallingford, Gruver, Dolliver, Fort Defiance State Park, Okamanpedan
State Park, Wolden County Park and Estherville Municipal Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4350 9444 4316 9444 4316 9483 4322 9483
      4328 9486 4329 9491 4350 9491
TIME...MOT...LOC 0459Z 248DEG 8KT 4336 9458 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Krull

267 
WWUS53 KDMX 270511
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
1211 AM CDT Fri Aug 27 2021

IAC063-147-270521-
/O.EXP.KDMX.SV.W.0103.000000T0000Z-210827T0515Z/
Emmet IA-Palo Alto IA-
1211 AM CDT Fri Aug 27 2021

...THE SEVERE THUNDERSTORM WARNING FOR EMMET AND NORTHERN PALO ALTO
COUNTIES WILL EXPIRE AT 1215 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 small
hail, gusty winds and heavy rain are still possible with this
thunderstorm.

LAT...LON 4350 9444 4316 9444 4316 9483 4322 9483
      4328 9486 4329 9491 4350 9491
TIME...MOT...LOC 0511Z 248DEG 8KT 4337 9455 

$$

Krull

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 26, 7:02 PM CDT	Severe Thunderstorm Warning	DMX	Audubon, Carroll	28 min
Aug 26, 8:35 PM CDT	Special Weather Statement	DMX	Poweshiek	40 min
Aug 26, 8:47 PM CDT	Severe Thunderstorm Warning	DMX	Mahaska, Poweshiek	58 min
Aug 26, 9:46 PM CDT	Special Weather Statement	DMX	Mahaska	44 min
Aug 26, 10:26 PM CDT	Special Weather Statement	DMX	Mahaska	34 min
Aug 26, 10:30 PM CDT	Severe Thunderstorm Warning	DMX	Emmet, Palo Alto	45 min
Aug 26, 10:52 PM CDT	Special Weather Statement	DMX	Wapello	38 min
Aug 27, 12:13 AM CDT	Special Weather Statement	DMX	Emmet	32 min
Aug 27, 2:08 PM CDT	Special Weather Statement	DMX	Hancock	37 min
Aug 27, 2:59 PM CDT	Special Weather Statement	DMX	Cerro Gordo	16 min
Aug 27, 4:23 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Hancock	52 min
Aug 27, 4:48 PM CDT	Tornado Warning	DMX	Cerro Gordo, Hancock	57 min
Aug 27, 4:58 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Franklin, Hancock	32 min
Aug 27, 5:23 PM CDT	Tornado Warning Tornado observed	DMX	Cerro Gordo	37 min
Aug 27, 5:25 PM CDT	Tornado Warning	DMX	Cerro Gordo	35 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.