Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 83, NWS Des Moines, IA

May 19, 20124 counties in Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 19, 2012, 9:00 PM CDT for 4 counties in Iowa. It was in force for 27 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 19, 2012, 9:00 PM CDT (02:00 UTC)
Expired: May 19, 2012, 9:27 PM CDT
In force: 27 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Audubon County, IA, Calhoun County, IA, Carroll County, IA, Sac County, IA

The radar

The Des Moines radar (KDMX), 116 km from the middle of the area, began a volume at 02:03 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 19, 9:10 PM CDT	TSTM WND DMG	Odebolt, IA	SEVERAL LARGE TREES KNOCKED DOWN IN A CEMETARY. WINDS ESTIMATED AT 60 MPH.
May 19, 9:14 PM CDT	TSTM WND GST 60	S Breda, IA	SPOTTER ESTIMATED WIND GUSTS NEAR 60 MPH FOR ABOUT 5 MINUTES.

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 19, 6:52 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 2.0 hours before the alert went out and 142 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: 1597 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 1383 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 122 m²/s²
0-3 km storm-relative helicity: 188 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 8.3

Open this sounding in Storm Lab

The text

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

493 
WUUS53 KDMX 200200
SVRDMX
IAC009-025-027-161-200245-
/O.NEW.KDMX.SV.W.0083.120520T0200Z-120520T0245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
900 PM CDT SAT MAY 19 2012

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN AUDUBON COUNTY IN WEST CENTRAL IOWA...
  WESTERN CALHOUN COUNTY IN WEST CENTRAL IOWA...
  CARROLL COUNTY IN WEST CENTRAL IOWA...
  SAC COUNTY IN WEST CENTRAL IOWA...

* UNTIL 945 PM CDT

* AT 854 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING AN EXTENDED
  PERIOD OF DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE
  LOCATED ALONG A LINE EXTENDING FROM IDA GROVE TO 8 MILES EAST OF
  DENISON TO 8 MILES SOUTHEAST OF IRWIN...AND MOVING NORTHEAST AT
  55 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  ODEBOLT...GRAY...AUDUBON AND ARCADIA AROUND 905 PM CDT.
  WALL LAKE...TEMPLETON...SCHALLER AND LAKE VIEW AROUND 910 PM CDT.
  EARLY...DEDHAM AND CARROLL AROUND 915 PM CDT.
  CARROLL AIRPORT...YETTER...WILLEY AND SAC CITY AROUND 920 PM CDT.

MULTIPLE REPORTS OF WINDS IN EXCESS OF 60 MPH HAVE BEEN REPORTED 
ACROSS CRAWFORD COUNTY.  BLOWING DUST AND DRAMATICALLY REDUCED 
VISIBILITIES MAY ALSO ACCOMPANY THESE SEVERE THUNDERSTORMS.

OTHER LOCATIONS IMPACTED BY THESE SEVERE THUNDERSTORMS INCLUDE
HALBUR...BREDA...NEMAHA...LIDDERDALE...AUBURN...LYTTON...RALSTON...
LANESBORO AND JOLLEY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE FOR DAMAGING WINDS...FALLING TREES AND FLYING DEBRIS. MOVE
INDOORS AND STAY AWAY FROM WINDOWS. IF YOU ARE IN A MOBILE HOME...
SEEK SHELTER IN A REINFORCED BUILDING.

&&

LAT...LON 4257 9539 4256 9479 4242 9465 4190 9463
      4186 9467 4186 9474 4180 9474 4157 9504
      4160 9505 4160 9510 4221 9509 4221 9533
      4247 9533 4248 9539
TIME...MOT...LOC 0158Z 227DEG 48KT 4243 9547 4208 9514
          4173 9507
WIND...HAIL 60MPH <.75IN

$$

SMALL

2 follow-up statements

885 
WWUS53 KDMX 200219
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
919 PM CDT SAT MAY 19 2012

IAC009-025-027-161-200245-
/O.CON.KDMX.SV.W.0083.000000T0000Z-120520T0245Z/
SAC IA-AUDUBON IA-CALHOUN IA-CARROLL IA-
919 PM CDT SAT MAY 19 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR CARROLL...
WESTERN CALHOUN...NORTHERN AUDUBON AND SAC COUNTIES UNTIL 945 PM
CDT...

AT 916 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN 
EXCESS OF 60 MPH.  THE LEADING EDGE OF THESE STORMS WAS LOCATED 
ALONG A LINE EXTENDING FROM 8 MILES SOUTH OF LAKESIDE TO 7 MILES 
NORTH OF CARROLL TO 7 MILES NORTH OF AUDUBON...MOVING NORTHEAST AT 
55 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  CARROLL AIRPORT...YETTER...SAC CITY AND LIDDERDALE AROUND 925 PM
  CDT.
  LYTTON...LANESBORO...LAKE CITY AND GLIDDEN AROUND 930 PM CDT.
  RALSTON AROUND 935 PM CDT.
  JOLLEY AROUND 940 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE FOR DAMAGING WINDS AND DEADLY CLOUD TO GROUND LIGHTNING. 
PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...PREFERABLY INSIDE A 
REINFORCED BUILDING AND AWAY FROM WINDOWS.

&&

LAT...LON 4257 9539 4256 9479 4242 9465 4190 9463
      4186 9467 4186 9474 4180 9474 4157 9504
      4160 9505 4160 9510 4221 9509 4221 9533
      4247 9533 4248 9539
TIME...MOT...LOC 0218Z 227DEG 48KT 4254 9520 4218 9487
          4183 9487
WIND...HAIL 60MPH <.75IN

$$

SMALL

020 
WWUS53 KDMX 200227
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
927 PM CDT SAT MAY 19 2012

IAC009-025-027-161-200237-
/O.CAN.KDMX.SV.W.0083.000000T0000Z-120520T0245Z/
SAC IA-AUDUBON IA-CALHOUN IA-CARROLL IA-
927 PM CDT SAT MAY 19 2012

...THE SEVERE THUNDERSTORM WARNING FOR CARROLL...WESTERN CALHOUN...
NORTHERN AUDUBON AND SAC COUNTIES IS CANCELLED...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAS WEAKENED BELOW
SEVERE LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR 
PROPERTY.  HOWEVER GUSTY WINDS TO 40 MPH ARE STILL POSSIBLE WITH 
THESE THUNDERSTORMS.

IN ADDITION...A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 
200 AM SUNDAY MORNING.

LAT...LON 4257 9539 4256 9479 4242 9465 4190 9463
      4186 9467 4186 9474 4180 9474 4157 9504
      4160 9505 4160 9510 4221 9509 4221 9533
      4247 9533 4248 9539
TIME...MOT...LOC 0227Z 227DEG 48KT 4262 9508 4226 9475
          4191 9475

$$

SMALL

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 19, 8:28 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	47 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.