Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 41, NWS Sioux Falls, SD

May 4, 2012Plymouth County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 4, 2012, 3:39 PM CDT for Plymouth County, Iowa. It was in force for 36 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 4, 2012, 3:39 PM CDT (20:39 UTC)
Expired: May 4, 2012, 4:15 PM CDT
In force: 36 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

County Plymouth County, IA

The radar

The Sioux Falls radar (KFSD), 99 km from the middle of the area, began a volume at 20:39 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, 3:40 PM CDT	TSTM WND GST 60	2 W Le Mars, IA
May 4, 3:47 PM CDT	TSTM WND GST 70	4 S 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, 8.7 hours before the alert went out and 166 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.

975 
WUUS53 KFSD 042039
SVRFSD
IAC149-042130-
/O.NEW.KFSD.SV.W.0041.120504T2039Z-120504T2130Z/

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

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN PLYMOUTH COUNTY IN NORTHWEST IOWA...

* UNTIL 430 PM CDT

* AT 339 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 SOUTH OF CRAIG...OR 7 MILES WEST OF LE MARS...AND
  MOVING EAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  STRUBLE AROUND 350 PM CDT...
  LE MARS AROUND 355 PM CDT...
  REMSEN AROUND 425 PM CDT...

OTHER LOCATIONS IMPACTED BY THIS SEVERE THUNDERSTORM INCLUDE OYENS.

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 4269 9641 4290 9641 4291 9598 4291 9585
      4271 9586
TIME...MOT...LOC 2039Z 266DEG 18KT 4282 9627
WIND...HAIL 60MPH 1.50IN

$$

SCHUMACHER

2 follow-up statements

503 
WWUS53 KFSD 042048
SVSFSD

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

IAC149-042130-
/O.CON.KFSD.SV.W.0041.000000T0000Z-120504T2130Z/
PLYMOUTH IA-
348 PM CDT FRI MAY 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHERN
PLYMOUTH COUNTY UNTIL 430 PM CDT...

AT 348 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING
A SEVERE THUNDERSTORM CAPABLE OF PRODUCING GOLF BALL SIZE HAIL...AND
DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THIS STORM WAS LOCATED NEAR
LE MARS...MOVING EAST AT 20 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
  LE MARS AROUND 355 PM CDT...
  REMSEN AROUND 425 PM CDT...

AT 347 PM CDT...A TRAINED SPOTTER REPORTED 65 TO 70 MPH WINDS 4 
MILES SOUTH OF LE MARS.

OTHER LOCATIONS IMPACTED BY THIS SEVERE THUNDERSTORM INCLUDE OYENS.

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 4269 9641 4290 9641 4291 9598 4291 9585
      4271 9586
TIME...MOT...LOC 2048Z 266DEG 18KT 4282 9621
WIND...HAIL 70MPH 1.75IN

$$

SCHUMACHER

443 
WWUS53 KFSD 042115
SVSFSD

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

IAC149-042126-
/O.CAN.KFSD.SV.W.0041.000000T0000Z-120504T2130Z/
PLYMOUTH IA-
415 PM CDT FRI MAY 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN PLYMOUTH COUNTY 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 GUSTY WINDS  TO 50 MPH ARE STILL POSSIBLE WITH 
THIS THUNDERSTORM.

LAT...LON 4269 9641 4290 9641 4291 9598 4291 9585
      4271 9586
TIME...MOT...LOC 2116Z 266DEG 18KT 4283 9602

$$

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, 3:18 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, 3:43 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.