Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 54, NWS Sioux Falls, SD

July 9, 2021Cherokee County, Plymouth County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 9, 2021, 12:29 AM CDT for Cherokee County, Plymouth County, Iowa. It was in force for 46 min. 2 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
Jul 9, 2021, 12:29 AM CDT (05:29 UTC)
Expired
Jul 9, 2021, 1:15 AM CDT
In force
46 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

Counties Cherokee County, IA, Plymouth County, IA

The radar

The Sioux Falls radar (KFSD), 117 km from the middle of the area, began a volume at 05:28 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

TimeReportWhereRemark
Jul 9, 12:29 AM CDTHAIL 15 S Le Mars, IAQUARTER SIZED HAIL AND HEAVY RAIN.
Jul 9, 12:31 AM CDTHAIL 15 E Merrill, IAQUARTER SIZED HAIL, HEAVY RAIN, AND NOT MUCH WIND.

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.

IssuedProductOfficeLasted
Jul 8, 9:33 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 5.5 hours before the alert went out and 158 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 2021-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 155 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, Omaha, NE at 00:00Z on 2021-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 200 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
155 J/kg
Mixed-layer CIN
-474 J/kg
Mixed-layer LCL
1131 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
200 m²/s²
0-3 km storm-relative helicity
406 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

632 
WUUS53 KFSD 090529
SVRFSD
IAC035-149-090615-
/O.NEW.KFSD.SV.W.0054.210709T0529Z-210709T0615Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
1229 AM CDT Fri Jul 9 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Cherokee County in northwestern Iowa...
  Eastern Plymouth County in northwestern Iowa...

* Until 115 AM CDT.

* At 1229 AM CDT, a severe thunderstorm was located near Le Mars,
  moving east at 50 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* This severe thunderstorm will be near...
  Remsen around 1240 AM CDT.
  Cleghorn around 1255 AM CDT.
  Quimby around 100 AM CDT.
  Cherokee around 105 AM CDT.
  Aurelia around 115 AM CDT.

Other locations impacted by this severe thunderstorm include
Brunsville, Oyens and Meriden.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4263 9630 4281 9631 4289 9539 4256 9539
TIME...MOT...LOC 0529Z 272DEG 42KT 4272 9612 

HAIL...1.00IN
WIND...<50MPH
 
$$

APT
2 follow-up statements
064 
WWUS53 KFSD 090547
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
1247 AM CDT Fri Jul 9 2021

IAC035-149-090615-
/O.CON.KFSD.SV.W.0054.000000T0000Z-210709T0615Z/
Cherokee IA-Plymouth IA-
1247 AM CDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 115 AM CDT
FOR CHEROKEE AND SOUTHEASTERN PLYMOUTH COUNTIES...

At 1246 AM CDT, a severe thunderstorm was located 8 miles south of
Marcus, or 15 miles west of Cherokee, moving east at 45 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

This severe storm will be near...
  Cleghorn around 1255 AM CDT.
  Quimby around 100 AM CDT.
  Cherokee around 110 AM CDT.
  Aurelia around 115 AM CDT.

Other locations impacted by this severe thunderstorm include Meriden.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4261 9602 4278 9602 4289 9539 4256 9539
TIME...MOT...LOC 0546Z 271DEG 40KT 4271 9586 

HAIL...1.00IN
WIND...<50MPH
 
$$

APT
440 
WWUS53 KFSD 090610
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
110 AM CDT Fri Jul 9 2021

IAC035-149-090620-
/O.EXP.KFSD.SV.W.0054.000000T0000Z-210709T0615Z/
Cherokee IA-Plymouth IA-
110 AM CDT Fri Jul 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR CHEROKEE AND SOUTHEASTERN
PLYMOUTH COUNTIES WILL EXPIRE AT 115 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
and heavy rain are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 300 AM CDT for
northwestern and west central Iowa.

LAT...LON 4261 9602 4278 9602 4289 9539 4256 9539
TIME...MOT...LOC 0610Z 272DEG 42KT 4270 9549 

$$

APT

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 8, 11:45 PM CDTSevere Thunderstorm WarningFSDWoodbury45 min
Jul 8, 11:50 PM CDTSevere Thunderstorm WarningFSDPlymouth, Sioux40 min
Jul 9, 12:44 AM CDTSevere Thunderstorm WarningFSDPlymouth, Sioux46 min
Jul 9, 12:46 AM CDTSevere Thunderstorm WarningFSDSioux44 min
Jul 9, 2:15 AM CDTSevere Thunderstorm WarningFSDPlymouth, Sioux45 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.