Alert archive / Iowa / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 69, NWS Sioux Falls, SD

May 12, 2011Ida County, Woodbury County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 12, 2011, 7:12 PM CDT for Ida County, Woodbury County, Iowa. It was in force for 28 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
May 12, 2011, 7:12 PM CDT (00:12 UTC)
Expired
May 12, 2011, 7:40 PM CDT
In force
28 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Hail
1.5 in
Wind
58.0 mph

Counties Ida County, IA, Woodbury County, IA

The radar

The Omaha radar (KOAX), 138 km from the middle of the area, began a volume at 00:15 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 12, 7:15 PM CDTHAIL 0.55 N Ida Grove, IAPEA TO MARBLE HAIL WHICH COVERED THE GROUND.
May 12, 7:15 PM CDTHAIL 15 S Galva, IA

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 12, 6:05 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.2 hours before the alert went out and 138 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 2011-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1648 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 2011-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 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
1648 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
900 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
50 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

170 
WUUS53 KFSD 130012
SVRFSD
IAC093-193-130100-
/O.NEW.KFSD.SV.W.0069.110513T0012Z-110513T0100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
712 PM CDT THU MAY 12 2011

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  IDA COUNTY IN NORTHWEST IOWA...
  SOUTHEASTERN WOODBURY COUNTY IN NORTHWEST IOWA...

* UNTIL 800 PM CDT

* AT 709 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE
  TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING WALNUT SIZE
  HAIL.  THIS STORM WAS LOCATED 5 MILES NORTH OF DANBURY...OR 15     
  MILES WEST OF IDA GROVE...AND MOVING NORTHEAST AT 15 MPH. A SECOND 
  STORM WAS LOCATED 3 MILES NORTHEAST OF IDA GROVE...ALSO CAPABLE OF 
  PRODUCING WALNUT SIZED HAIL AND MOVING NORTHEAST AT 15 MPH. 

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  BATTLE CREEK AND CUSHING AROUND 730 PM CDT...
  IDA GROVE AND HOLSTEIN AROUND 755 PM CDT...
  ARTHUR AND GALVA AROUND 800 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS EXHIBITED SOME WEAK ROTATION. TORNADOES CAN DEVELOP
QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH ONE IS NOT IMMEDIATELY
LIKELY...IF A TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF
SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL
INTERIOR ROOM.

THIS STORM HAS A HISTORY OF PRODUCING LARGE HAIL. SEEK SHELTER NOW
INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS!

&&

LAT...LON 4239 9589 4249 9581 4257 9562 4256 9539
      4249 9538 4248 9534 4247 9532 4229 9533
      4221 9556 4220 9575
TIME...MOT...LOC 0009Z 247DEG 15KT 4232 9574
WIND...HAIL <58MPH 1.50IN

$$

LIEBL
2 follow-up statements
861 
WWUS53 KFSD 130033
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
733 PM CDT THU MAY 12 2011

IAC093-193-130100-
/O.CON.KFSD.SV.W.0069.000000T0000Z-110513T0100Z/
WOODBURY IA-IDA IA-
733 PM CDT THU MAY 12 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR IDA AND EAST
CENTRAL WOODBURY COUNTIES UNTIL 800 PM CDT...

AT 733 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING
A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS
STORM WAS LOCATED NEAR CUSHING...OR 9 MILES NORTHWEST OF IDA GROVE...
MOVING NORTHEAST AT 20 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  HOLSTEIN AROUND 745 PM CDT...
  GALVA AROUND 755 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING LARGE HAIL. SEEK SHELTER NOW
INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS!

&&

LAT...LON 4228 9566 4251 9576 4257 9562 4256 9539
      4249 9538 4249 9536 4247 9532 4234 9533
      4230 9557
TIME...MOT...LOC 0033Z 227DEG 16KT 4244 9560
WIND...HAIL <58MPH 1.00IN

$$

LIEBL
424 
WWUS53 KFSD 130040
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
740 PM CDT THU MAY 12 2011

IAC093-193-130050-
/O.CAN.KFSD.SV.W.0069.000000T0000Z-110513T0100Z/
WOODBURY IA-IDA IA-
740 PM CDT THU MAY 12 2011

...THE SEVERE THUNDERSTORM WARNING FOR IDA AND EAST CENTRAL WOODBURY
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...HOWEVER SMALL HAIL IS STILL POSSIBLE WITH THIS
THUNDERSTORM.

LAT...LON 4228 9566 4251 9576 4257 9562 4256 9539
      4249 9538 4249 9536 4247 9532 4234 9533
      4230 9557
TIME...MOT...LOC 0040Z 227DEG 16KT 4246 9557

$$

LIEBL

The office that day

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

IssuedProductOfficeCountiesLasted
May 12, 7:18 PM CDTSevere Thunderstorm WarningFSDBuena Vista42 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2011Every severe thunderstorm warning in 2011

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.