Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 44, NWS Sioux Falls, SD

May 4, 2012Clay County, O'Brien County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 4, 2012, 4:12 PM CDT for Clay County, O'Brien County, Iowa. It was in force for 33 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
May 4, 2012, 4:12 PM CDT (21:12 UTC)
Expired
May 4, 2012, 4:45 PM CDT
In force
33 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Clay County, IA, O'Brien County, IA

The radar

The Sioux Falls radar (KFSD), 127 km from the middle of the area, began a volume at 21:16 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
May 4, 4:15 PM CDTTSTM WND GST 604 Ene Hartley, IASMALL BRANCHES DOWN.

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
May 4, 2:00 PM CDTSevere Thunderstorm WatchSPC9 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 9.2 hours before the alert went out and 213 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 12:00Z on 2012-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2705 joules per kilogram.LCLLFCEL10008507005003002001001 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 12:00Z on 2012-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.1939Sfc1 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
2705 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
584 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
98 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

836 
WUUS53 KFSD 042112
SVRFSD
IAC041-141-042145-
/O.NEW.KFSD.SV.W.0044.120504T2112Z-120504T2145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
412 PM CDT FRI MAY 4 2012

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN CLAY COUNTY IN NORTHWEST IOWA...
  EASTERN O'BRIEN COUNTY IN NORTHWEST IOWA...

* UNTIL 445 PM CDT

* AT 412 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE
  TRACKING A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED
  ALONG A LINE EXTENDING FROM 7 MILES NORTHEAST OF HARTLEY TO EVERLY
  TO SUTHERLAND...AND MOVING EAST AT 40 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  ROYAL AROUND 420 PM CDT...
  GREENVILLE AROUND 435 PM CDT...

OTHER LOCATIONS IMPACTED BY THESE SEVERE THUNDERSTORMS INCLUDE
ROSSIE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

THIS STORM HAS A HISTORY OF PRODUCING DAMAGING WIND. THIS IS AN
EXTREMELY DANGEROUS SITUATION. SEEK SHELTER NOW INSIDE A STURDY
STRUCTURE AND STAY AWAY FROM WINDOWS.

&&

LAT...LON 4291 9503 4291 9564 4313 9551 4326 9553
      4326 9539 4310 9540 4312 9503
TIME...MOT...LOC 2112Z 264DEG 35KT 4327 9539 4314 9536
          4303 9543
WIND...HAIL 60MPH <1.00IN

$$

SCHUMACHER
2 follow-up statements
590 
WWUS53 KFSD 042132
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
432 PM CDT FRI MAY 4 2012

IAC141-042142-
/O.CAN.KFSD.SV.W.0044.000000T0000Z-120504T2145Z/
O'BRIEN IA-
432 PM CDT FRI MAY 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN O'BRIEN COUNTY IS
CANCELLED...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAVE MOVED OUT OF THE 
WARNED AREA.

LAT...LON 4291 9503 4291 9539 4311 9530 4312 9503
TIME...MOT...LOC 2132Z 264DEG 35KT 4329 9512 4316 9509
          4305 9517

$$

IAC041-042145-
/O.CON.KFSD.SV.W.0044.000000T0000Z-120504T2145Z/
CLAY IA-
432 PM CDT FRI MAY 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHERN CLAY
COUNTY UNTIL 445 PM CDT...

AT 432 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING
A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DESTRUCTIVE WINDS
IN EXCESS OF 70 MPH.  THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM MILFORD TO SPENCER TO GREENVILLE...MOVING EAST AT 40
MPH.

THIS LINE OF SEVERE THUNDERSTORMS WILL AFFECT MAINLY RURAL AREAS OF
SOUTHERN CLAY COUNTY...INCLUDING THE FOLLOWING LOCATIONS GILLETT
GROVE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 4291 9503 4291 9539 4311 9530 4312 9503
TIME...MOT...LOC 2132Z 264DEG 35KT 4329 9512 4316 9509
          4305 9517
WIND...HAIL 70MPH <1.00IN

$$

SCHUMACHER
010 
WWUS53 KFSD 042145
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
445 PM CDT FRI MAY 4 2012

IAC041-042155-
/O.EXP.KFSD.SV.W.0044.000000T0000Z-120504T2145Z/
CLAY IA-
445 PM CDT FRI MAY 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN CLAY COUNTY HAS
EXPIRED...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAVE MOVED OUT OF THE
WARNED AREA.

LAT...LON 4291 9503 4291 9539 4311 9530 4312 9503
TIME...MOT...LOC 2132Z 264DEG 35KT 4328 9512 4315 9509
          4305 9517

$$

SCHUMACHER

The office that day

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

IssuedProductOfficeCountiesLasted
May 3, 7:57 PM CDTSevere Thunderstorm WarningFSDCherokee33 min
May 3, 8:05 PM CDTFlash Flood WarningFSDCherokee93 min
May 3, 8:37 PM CDTSevere Thunderstorm WarningFSDBuena Vista, Cherokee38 min
May 4, 3:00 PM CDTSevere Thunderstorm WarningFSDSioux30 min
May 4, 3:14 PM CDTSevere Thunderstorm WarningFSDPlymouth, Sioux31 min
May 4, 3:18 PM CDTSevere Thunderstorm WarningFSDO'Brien, Osceola, Sioux42 min
May 4, 3:20 PM CDTTornado WarningFSDO'Brien, Sioux25 min
May 4, 3:39 PM CDTSevere Thunderstorm WarningFSDPlymouth36 min
May 4, 3:43 PM CDTTornado WarningFSDO'Brien, Sioux32 min
May 4, 4:01 PM CDTSevere Thunderstorm WarningFSDCherokee, O'Brien29 min
May 4, 4:06 PM CDTTornado WarningFSDClay24 min
May 4, 4:09 PM CDTSevere Thunderstorm WarningFSDDickinson, Osceola51 min
May 4, 4:25 PM CDTSevere Thunderstorm WarningFSDClay35 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2012Every severe thunderstorm warning in 2012

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.