Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 28, NWS Sioux Falls, SD

May 1, 2012Buena Vista County, Clay County, Dickinson County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 1, 2012, 10:13 PM CDT for Buena Vista County, Clay County, Dickinson County, Iowa. It was in force for 17 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 1, 2012, 10:13 PM CDT (03:13 UTC)
Expired: May 1, 2012, 10:30 PM CDT
In force: 17 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Buena Vista County, IA, Clay County, IA, Dickinson County, IA

The radar

The Sioux Falls radar (KFSD), 149 km from the middle of the area, began a volume at 03:16 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

Time	Report	Where	Remark
May 1, 10:18 PM CDT	TSTM WND GST 65	3 Ne Dickens, IA	DAMAGE TO ROOF.
May 1, 10:22 PM CDT	HAIL 0.88	5 W Estherville, 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.

Issued	Product	Office	Lasted
May 1, 9:18 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 3.2 hours before the alert went out and 226 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: 1502 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 1477 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 75 m²/s²
0-3 km storm-relative helicity: 122 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 5.2

Open this sounding in Storm Lab

The text

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

453 
WUUS53 KFSD 020313
SVRFSD
IAC021-041-059-020330-
/O.NEW.KFSD.SV.W.0028.120502T0313Z-120502T0330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1013 PM CDT TUE MAY 1 2012

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN BUENA VISTA COUNTY IN NORTHWEST IOWA...
  EASTERN CLAY COUNTY IN NORTHWEST IOWA...
  EASTERN DICKINSON COUNTY IN NORTHWEST IOWA...

* UNTIL 1030 PM CDT

* AT 1013 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 SUPERIOR TO 11 MILES EAST OF SPENCER TO
  SIOUX RAPIDS...AND MOVING EAST AT 35 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  WEBB AROUND 1020 PM CDT...
  MARATHON AROUND 1025 PM CDT...

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 4280 9491 4281 9526 4312 9503 4349 9508
      4349 9490
TIME...MOT...LOC 0313Z 271DEG 31KT 4347 9497 4311 9491
          4283 9517
WIND...HAIL 60MPH <1.00IN

$$

CJ

1 follow-up statement

603 
WWUS53 KFSD 020326
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1026 PM CDT TUE MAY 1 2012

IAC021-041-059-020336-
/O.EXP.KFSD.SV.W.0028.000000T0000Z-120502T0330Z/
DICKINSON IA-BUENA VISTA IA-CLAY IA-
1026 PM CDT TUE MAY 1 2012

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN CLAY...NORTHEASTERN
BUENA VISTA AND EASTERN DICKINSON COUNTIES WILL EXPIRE AT 1030 PM
CDT...

THE LINE OF STORMS WHICH PROMPTED THE WARNING WERE MOVING OUT OF THE 
WARNED AREA.

LAT...LON 4280 9491 4281 9526 4312 9503 4349 9508
      4349 9490
TIME...MOT...LOC 0326Z 271DEG 31KT 4346 9481 4310 9476
          4282 9502

$$

CJ

The office that day

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

Issued	Product	Office	Counties	Lasted
May 1, 7:12 PM CDT	Severe Thunderstorm Warning	FSD	Lyon, Sioux	33 min
May 1, 7:27 PM CDT	Tornado Warning	FSD	Lyon, Sioux	33 min
May 1, 7:41 PM CDT	Severe Thunderstorm Warning	FSD	Lyon, Sioux	34 min
May 1, 7:57 PM CDT	Tornado Warning	FSD	Lyon	33 min
May 1, 8:09 PM CDT	Severe Thunderstorm Warning	FSD	Lyon	36 min
May 1, 8:40 PM CDT	Flash Flood Warning	FSD	Lyon	3 hr
May 1, 9:15 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Cherokee, Clay, O'Brien, Plymouth, Sioux	30 min
May 1, 9:22 PM CDT	Severe Thunderstorm Warning	FSD	Dickinson, Osceola	38 min
May 1, 9:29 PM CDT	Tornado Warning	FSD	Clay, O'Brien	46 min
May 1, 9:41 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Cherokee, Clay, Dickinson, O'Brien, Osceola	34 min
May 1, 9:44 PM CDT	Tornado Warning	FSD	Clay	31 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2012 Every 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.