Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 217, NWS Sioux Falls, SD

September 4, 20124 counties in Iowa; Jackson County, Nobles County, Minnesota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Sep 4, 2012, 9:32 PM CDT for 4 counties in Iowa; Jackson County, Nobles County, Minnesota. It was in force for 58 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: Sep 4, 2012, 9:32 PM CDT (02:32 UTC)
Expired: Sep 4, 2012, 10:30 PM CDT
In force: 58 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Clay County, IA, Dickinson County, IA, O'Brien County, IA, Osceola County, IA, Jackson County, MN, Nobles County, MN

The radar

The Sioux Falls radar (KFSD), 129 km from the middle of the area, began a volume at 02:34 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
Sep 4, 10:00 PM CDT	TSTM WND GST 60	Spirit Lake, IA
Sep 4, 10:13 PM CDT	TSTM WND GST 60	6 W Spirit Lake, IA
Sep 4, 10:15 PM CDT	TSTM WND GST 60	2 Sw Spirit Lake, 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
Sep 4, 7:45 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 2.5 hours before the alert went out and 212 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 3109 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 4 m²/s²
0-3 km storm-relative helicity: 63 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.

502 
WUUS53 KFSD 050232
SVRFSD
IAC041-059-141-143-MNC063-105-050330-
/O.NEW.KFSD.SV.W.0217.120905T0232Z-120905T0330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
932 PM CDT TUE SEP 4 2012

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CLAY COUNTY IN NORTHWEST IOWA...
  DICKINSON COUNTY IN NORTHWEST IOWA...
  O'BRIEN COUNTY IN NORTHWEST IOWA...
  OSCEOLA COUNTY IN NORTHWEST IOWA...
  SOUTHERN JACKSON COUNTY IN SOUTHWEST MINNESOTA...
  SOUTHEASTERN NOBLES COUNTY IN SOUTHWEST MINNESOTA...

* UNTIL 1030 PM CDT

* AT 932 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 WORTHINGTON TO MELVIN TO 5 MILES   
SOUTHEAST OF GRANVILLE...AND MOVING EAST AT 50 MPH. THE STRONGEST 
WINDS ARE AHEAD OF THE RAIN IN THE THUNDERSTORM OUTFLOW.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  HARTLEY...HARRIS AND ROUND LAKE AROUND 940 PM CDT...
  SUTHERLAND AND LAKE PARK AROUND 945 PM CDT...
  EVERLY AROUND 950 PM CDT...
  ROYAL...WEST OKOBOJI...WAHPETON AND MILFORD AROUND 955 PM CDT...
  SPENCER...FOSTORIA...SPIRIT LAKE AND ORLEANS AROUND 1000 PM CDT...
  GREENVILLE AND TERRIL AROUND 1005 PM CDT...
  SUPERIOR AROUND 1010 PM CDT...
  WEBB AROUND 1015 PM CDT...

OTHER LOCATIONS IMPACTED BY THESE SEVERE THUNDERSTORMS INCLUDE
CALUMET...MONETA...ROSSIE...DICKENS AND GILLETT GROVE.

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 4349 9490 4294 9491 4292 9492 4292 9577
      4329 9572 4362 9573 4361 9485 4351 9485
TIME...MOT...LOC 0232Z 266DEG 45KT 4358 9559 4330 9557
          4294 9576
WIND...HAIL 60MPH <1.00IN

$$

CHENARD

1 follow-up statement

786 
WWUS53 KFSD 050301 RRA
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1001 PM CDT TUE SEP 4 2012

IAC041-059-141-143-MNC063-105-050330-
/O.CON.KFSD.SV.W.0217.000000T0000Z-120905T0330Z/
OSCEOLA IA-O'BRIEN IA-DICKINSON IA-CLAY IA-JACKSON MN-NOBLES MN-
1001 PM CDT TUE SEP 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHEASTERN
NOBLES...SOUTHERN JACKSON...CLAY...DICKINSON...O'BRIEN AND OSCEOLA
COUNTIES UNTIL 1030 PM CDT...

AT 1001 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE
TRACKING A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING
DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THESE STORMS WERE LOCATED
ALONG A LINE EXTENDING FROM 6 MILES SOUTH OF LAKEFIELD TO MILFORD TO 
PETERSON...MOVING EAST AT 50 MPH. THE STRONGEST WINDS ARE AHEAD OF 
THE RAIN ALONG THE THUNDERSTORM OUTFLOW. 

SEVERE THUNDERSTORMS WILL BE NEAR...
  GREENVILLE...TERRIL AND SUPERIOR AROUND 1010 PM CDT...
  WEBB AROUND 1020 PM CDT...

OTHER LOCATIONS IMPACTED BY THIS LINE OF SEVERE THUNDERSTORMS INCLUDE
GILLETT GROVE AND DICKENS.

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 4349 9490 4294 9491 4292 9492 4292 9577
      4329 9572 4362 9573 4361 9485 4351 9485
TIME...MOT...LOC 0301Z 266DEG 45KT 4360 9513 4332 9511
          4296 9530
WIND...HAIL 70MPH <1.00IN

$$

CHENARD

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 4, 8:14 PM CDT	Severe Thunderstorm Warning	FSD	Lyon, Sioux	46 min
Sep 4, 8:55 PM CDT	Severe Thunderstorm Warning	FSD	Lyon, O'Brien, Osceola, Sioux	50 min
Sep 4, 8:57 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee, Plymouth, Sioux, Woodbury	48 min
Sep 4, 9:44 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Cherokee, Clay, Ida, O'Brien, Plymouth and 1 more	61 min
Sep 4, 10:15 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth, Sioux	45 min
Sep 4, 10:28 PM CDT	Severe Thunderstorm Warning	FSD	Clay, Dickinson, O'Brien, Osceola	47 min
Sep 4, 10:45 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee, O'Brien, Plymouth, Sioux	45 min
Sep 4, 11:27 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Cherokee, Ida, Plymouth, Woodbury	48 min
Sep 4, 8:52 PM CDT	Severe Thunderstorm Warning	FSD	Pipestone, Rock	38 min
Sep 4, 9:28 PM CDT	Severe Thunderstorm Warning	FSD	Murray, Nobles, Pipestone, Rock	47 min
Sep 4, 10:04 PM CDT	Severe Thunderstorm Warning	FSD	Cottonwood, Jackson, Murray, Nobles	56 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2012 Severe Thunderstorm Warnings in Minnesota, 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.