Alert archive / Iowa / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 7, NWS Sioux Falls, SD

April 5, 2021Lyon County, Iowa; Minnehaha County, South Dakota; Rock County, Minnesota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Apr 5, 2021, 9:48 PM CDT for Lyon County, Iowa; Minnehaha County, South Dakota; Rock County, Minnesota. It was in force for 27 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
Apr 5, 2021, 9:48 PM CDT (02:48 UTC)
Expired
Apr 5, 2021, 10:15 PM CDT
In force
27 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Hail
1.25 in
Wind
60.0 mph

Counties Lyon County, IA, Rock County, MN, Minnehaha County, SD

The radar

The Sioux Falls radar (KFSD), 36 km from the middle of the area, began a volume at 02:52 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
Apr 5, 9:50 PM CDTHAIL 0.752 Ese Lester, IA
Apr 5, 10:02 PM CDTHAIL 1.251 Ssw Rock Rapids, IA

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

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 2.8 hours before the alert went out and 231 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, Aberdeen, SD at 00:00Z on 2021-04-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Aberdeen, SD at 00:00Z on 2021-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -70 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
3053 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
-70 m²/s²
0-3 km storm-relative helicity
246 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

608 
WUUS53 KFSD 060248
SVRFSD
IAC119-MNC133-SDC099-060315-
/O.NEW.KFSD.SV.W.0007.210406T0248Z-210406T0315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
948 PM CDT Mon Apr 5 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Northwestern Lyon County in northwestern Iowa...
  Southern Rock County in southwestern Minnesota...
  Southeastern Minnehaha County in southeastern South Dakota...

* Until 1015 PM CDT.

* At 947 PM CDT, a severe thunderstorm was located over Larchwood, or
  11 miles west of Rock Rapids, moving east 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 be near...
  Rock Rapids around 1005 PM CDT.

Other locations impacted by this severe thunderstorm include Steen.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4334 9647 4352 9652 4362 9616 4338 9607
TIME...MOT...LOC 0247Z 251DEG 23KT 4346 9639 

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

SG
1 follow-up statement
010 
WWUS53 KFSD 060303
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
1003 PM CDT Mon Apr 5 2021

SDC099-060313-
/O.CAN.KFSD.SV.W.0007.000000T0000Z-210406T0315Z/
Minnehaha SD-
1003 PM CDT Mon Apr 5 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MINNEHAHA COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4335 9639 4357 9635 4362 9616 4338 9607
TIME...MOT...LOC 0303Z 260DEG 26KT 4345 9618 

$$

IAC119-MNC133-060315-
/O.CON.KFSD.SV.W.0007.000000T0000Z-210406T0315Z/
Lyon IA-Rock MN-
1003 PM CDT Mon Apr 5 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1015 PM CDT
FOR NORTH CENTRAL LYON AND SOUTHEASTERN ROCK COUNTIES...

At 1003 PM CDT, a severe thunderstorm was located over Rock Rapids,
moving east at 30 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Public. At 950 PM, quarter sized hail was reported at 
         Larchwood.

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 north
central Lyon and southeastern Rock Counties, including the following
locations... Steen.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4335 9639 4357 9635 4362 9616 4338 9607
TIME...MOT...LOC 0303Z 260DEG 26KT 4345 9618 

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

SG

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 5, 9:27 PM CDTSevere Thunderstorm WarningFSDLyon33 min
Apr 5, 10:07 PM CDTSevere Thunderstorm WarningFSDLyon, O'Brien, Osceola53 min
Apr 5, 7:03 PM CDTSevere Thunderstorm WarningFSDMcCook, Minnehaha27 min
Apr 5, 7:39 PM CDTSevere Thunderstorm WarningFSDMoody36 min
Apr 5, 7:49 PM CDTSevere Thunderstorm WarningFSDHutchinson, Turner26 min
Apr 5, 8:44 PM CDTSevere Thunderstorm WarningFSDMinnehaha31 min
Apr 5, 9:04 PM CDTSevere Thunderstorm WarningFSDLincoln, Minnehaha, Turner26 min
Apr 6, 9:39 AM CDTSevere Thunderstorm WarningFSDCharles Mix, Gregory10 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2021Severe Thunderstorm Warnings in South Dakota, 2021Severe Thunderstorm Warnings in Minnesota, 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.