Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 173, NWS Sioux Falls, SD

July 25, 2012Woodbury County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 25, 2012, 5:16 PM CDT for Woodbury County, Iowa. It was in force for 29 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: Jul 25, 2012, 5:16 PM CDT (22:16 UTC)
Expired: Jul 25, 2012, 5:45 PM CDT
In force: 29 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

County Woodbury County, IA

The radar

The Omaha radar (KOAX), 128 km from the middle of the area, began a volume at 22:16 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
Jul 25, 5:30 PM CDT	HAIL 1.25	4 S Moville, IA
Jul 25, 5:47 PM CDT	HAIL 1.75	5 Sse Moville, 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
Jul 25, 5:16 PM CDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.3 hours before the alert went out and 128 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: 675 J/kg
Mixed-layer CIN: -402 J/kg
Mixed-layer LCL: 2150 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 198 m²/s²
0-3 km storm-relative helicity: 222 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

141 
WUUS53 KFSD 252216
SVRFSD
IAC193-252245-
/O.NEW.KFSD.SV.W.0173.120725T2216Z-120725T2245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
516 PM CDT WED JUL 25 2012

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL WOODBURY COUNTY IN WEST CENTRAL IOWA...

* UNTIL 545 PM CDT

* AT 517 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE
  TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING HALF DOLLAR
  SIZE HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
  LOCATED NEAR MOVILLE...OR 18 MILES EAST OF SIOUX CITY...AND MOVING
  EAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  ANTHON AROUND 540 PM CDT...
  PIERSON AROUND 545 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 4233 9615 4249 9621 4257 9590 4256 9584
      4236 9576
TIME...MOT...LOC 2217Z 259DEG 15KT 4243 9603
WIND...HAIL 60MPH 1.25IN

$$

SCHUMACHER

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 25, 5:11 PM CDT	Severe Thunderstorm Warning	FSD	Sioux	34 min
Jul 25, 5:15 PM CDT	Severe Thunderstorm Warning	FSD	Dickinson	39 min
Jul 25, 5:25 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee, O'Brien	35 min
Jul 25, 5:31 PM CDT	Severe Thunderstorm Warning	FSD	Woodbury	59 min
Jul 25, 5:43 PM CDT	Severe Thunderstorm Warning	FSD	Woodbury	47 min
Jul 25, 6:03 PM CDT	Severe Thunderstorm Warning	FSD	Clay, Dickinson	42 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.