Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 37, NWS Sioux Falls, SD

May 4, 2012Plymouth County, Sioux County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 4, 2012, 3:14 PM CDT for Plymouth County, Sioux County, Iowa. It was in force for 31 min. 3 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, 3:14 PM CDT (20:14 UTC)
Expired: May 4, 2012, 3:45 PM CDT
In force: 31 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

Counties Plymouth County, IA, Sioux County, IA

The radar

The Sioux Falls radar (KFSD), 87 km from the middle of the area, began a volume at 20:16 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 4, 3:30 PM CDT	TSTM WND GST 60	Brunsville, IA	WALNUT SIZE HAIL ALSO OCCURRED.
May 4, 3:30 PM CDT	HAIL 1.5	Brunsville, IA
May 4, 3:40 PM CDT	TSTM WND GST 60	2 W Le Mars, 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, 8.2 hours before the alert went out and 170 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.

311 
WUUS53 KFSD 042014
SVRFSD
IAC149-167-042045-
/O.NEW.KFSD.SV.W.0037.120504T2014Z-120504T2045Z/

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

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN PLYMOUTH COUNTY IN NORTHWEST IOWA...
  SOUTHWESTERN SIOUX COUNTY IN NORTHWEST IOWA...

* UNTIL 345 PM CDT

* AT 315 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 6 MILES EAST OF AKRON...OR 13 MILES SOUTH OF HAWARDEN...AND
  MOVING NORTHEAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  CRAIG AROUND 335 PM CDT...
  STRUBLE AND LE MARS AROUND 345 PM CDT...

OTHER LOCATIONS IMPACTED BY THIS SEVERE THUNDERSTORM INCLUDE
BRUNSVILLE.

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 9653 4296 9613 4275 9613 4273 9656
TIME...MOT...LOC 2015Z 247DEG 19KT 4282 9641
WIND...HAIL 60MPH 1.50IN

$$

SCHUMACHER

1 follow-up statement

984 
WWUS53 KFSD 042031
SVSFSD

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

IAC167-042041-
/O.CAN.KFSD.SV.W.0037.000000T0000Z-120504T2045Z/
SIOUX IA-
331 PM CDT FRI MAY 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN SIOUX COUNTY IS
CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED 
AREA.

LAT...LON 4290 9644 4292 9616 4291 9614 4275 9613
      4275 9643
TIME...MOT...LOC 2031Z 247DEG 19KT 4285 9630

$$

IAC149-042045-
/O.CON.KFSD.SV.W.0037.000000T0000Z-120504T2045Z/
PLYMOUTH IA-
331 PM CDT FRI MAY 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTH CENTRAL
PLYMOUTH COUNTY UNTIL 345 PM CDT...

AT 331 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING
A SEVERE THUNDERSTORM CAPABLE OF PRODUCING GOLF BALL SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
CRAIG...OR 9 MILES NORTHWEST OF LE MARS...MOVING NORTHEAST AT 20 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  LE MARS AROUND 340 PM CDT...
  STRUBLE AROUND 345 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 4290 9644 4292 9616 4291 9614 4275 9613
      4275 9643
TIME...MOT...LOC 2031Z 247DEG 19KT 4285 9630
WIND...HAIL 60MPH 1.75IN

$$

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, 3:18 PM CDT	Severe Thunderstorm Warning	FSD	O'Brien, Osceola, Sioux	42 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.