Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 38, NWS Sioux Falls, SD

May 4, 2012O'Brien County, Osceola County, Sioux County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 4, 2012, 3:18 PM CDT for O'Brien County, Osceola County, Sioux County, Iowa. It was in force for 42 min. 8 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 4, 2012, 3:18 PM CDT (20:18 UTC)
Expired: May 4, 2012, 4:00 PM CDT
In force: 42 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

Counties O'Brien County, IA, Osceola County, IA, Sioux County, IA

The radar

The Sioux Falls radar (KFSD), 80 km from the middle of the area, began a volume at 20:20 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 4, 3:20 PM CDT	TSTM WND GST 61	1 Wsw Orange City, IA
May 4, 3:22 PM CDT	TORNADO	3 N Orange City, IA
May 4, 3:23 PM CDT	TSTM WND GST 79	1 Ssw Orange City, IA
May 4, 3:40 PM CDT	TSTM WND DMG	3 E Hospers, IA	SMALL BRANCHES BROKEN.
May 4, 3:40 PM CDT	NON-TSTM WND DMG	3 E Hospers, IA	SMALL BRANCHES BROKEN.
May 4, 3:45 PM CDT	TSTM WND GST 60	Sheldon, IA
May 4, 3:46 PM CDT	TSTM WND GST 70	N Hospers, IA	PEA SIZE HAIL WAS ALSO PRESENT.
May 4, 3:50 PM CDT	TORNADO	3 W Primghar, 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 4, 2:00 PM CDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 8.3 hours before the alert went out and 207 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: 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.

159 
WUUS53 KFSD 042018
SVRFSD
IAC141-143-167-042100-
/O.NEW.KFSD.SV.W.0038.120504T2018Z-120504T2100Z/

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

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN O'BRIEN COUNTY IN NORTHWEST IOWA...
  SOUTHWESTERN OSCEOLA COUNTY IN NORTHWEST IOWA...
  EASTERN SIOUX COUNTY IN NORTHWEST IOWA...

* UNTIL 400 PM CDT

* AT 318 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE
  TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING WALNUT SIZE
  HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
  LOCATED NEAR SIOUX CENTER...OR 9 MILES NORTHWEST OF ORANGE CITY...
  AND MOVING EAST AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  ALTON AROUND 325 PM CDT...
  BOYDEN AROUND 330 PM CDT...
  HOSPERS AND MATLOCK AROUND 335 PM CDT...
  SHELDON AROUND 340 PM CDT...
  ARCHER AROUND 350 PM CDT...
  SANBORN AROUND 355 PM CDT...
  PRIMGHAR AROUND 400 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 4295 9616 4323 9626 4326 9595 4326 9587
      4327 9587 4330 9563 4303 9554
TIME...MOT...LOC 2018Z 262DEG 32KT 4312 9612
WIND...HAIL 60MPH 1.50IN

$$

MJF

1 follow-up statement

402 
WWUS53 KFSD 042047
SVSFSD

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

IAC141-143-167-042100-
/O.CON.KFSD.SV.W.0038.000000T0000Z-120504T2100Z/
SIOUX IA-OSCEOLA IA-O'BRIEN IA-
347 PM CDT FRI MAY 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHWESTERN
O'BRIEN...SOUTHWESTERN OSCEOLA AND EASTERN SIOUX COUNTIES UNTIL 400
PM CDT...

AT 346 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING
A SEVERE THUNDERSTORM CAPABLE OF PRODUCING WALNUT SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
SHELDON...OR 16 MILES NORTHEAST OF ORANGE CITY...MOVING EAST AT 35
MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  SANBORN AND PRIMGHAR AROUND 355 PM CDT...

AT 345 PM CDT...TRAINED SPOTTERS REPORTED 60 MPH WINDS IN SHELDON.

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 4303 9554 4297 9602 4325 9608 4326 9595
      4326 9587 4327 9587 4330 9563
TIME...MOT...LOC 2046Z 262DEG 32KT 4315 9578
WIND...HAIL 60MPH 1.50IN

$$

SCHUMACHER

The office that day

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

Issued	Product	Office	Counties	Lasted
May 3, 7:57 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee	33 min
May 3, 8:05 PM CDT	Flash Flood Warning	FSD	Cherokee	93 min
May 3, 8:37 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Cherokee	38 min
May 4, 3:00 PM CDT	Severe Thunderstorm Warning	FSD	Sioux	30 min
May 4, 3:14 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth, Sioux	31 min
May 4, 3:20 PM CDT	Tornado Warning	FSD	O'Brien, Sioux	25 min
May 4, 3:39 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth	36 min
May 4, 3:43 PM CDT	Tornado Warning	FSD	O'Brien, Sioux	32 min
May 4, 4:01 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee, O'Brien	29 min
May 4, 4:06 PM CDT	Tornado Warning	FSD	Clay	24 min
May 4, 4:09 PM CDT	Severe Thunderstorm Warning	FSD	Dickinson, Osceola	51 min
May 4, 4:12 PM CDT	Severe Thunderstorm Warning	FSD	Clay, O'Brien	33 min
May 4, 4:25 PM CDT	Severe Thunderstorm Warning	FSD	Clay	35 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.