Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 3, NWS Des Moines, IA

March 29, 2012Audubon County, Cass County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Mar 29, 2012, 7:25 PM CDT for Audubon County, Cass County, Iowa. It was in force for 50 min. 1 report 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: Mar 29, 2012, 7:25 PM CDT (00:25 UTC)
Expired: Mar 29, 2012, 8:15 PM CDT
In force: 50 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Audubon County, IA, Cass County, IA

The radar

The Des Moines radar (KDMX), 106 km from the middle of the area, began a volume at 00:28 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
Mar 29, 7:54 PM CDT	HAIL 1.75	4 Ne Griswold, IA

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.4 hours before the alert went out and 119 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: 761 J/kg
Mixed-layer CIN: -64 J/kg
Mixed-layer LCL: 647 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 76 m²/s²
0-3 km storm-relative helicity: 99 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.5

Open this sounding in Storm Lab

The text

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

300 
WUUS53 KDMX 300025
SVRDMX
IAC009-029-300115-
/O.NEW.KDMX.SV.W.0003.120330T0025Z-120330T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
725 PM CDT THU MAR 29 2012

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN AUDUBON COUNTY IN WEST CENTRAL IOWA...
  NORTHWESTERN CASS COUNTY IN SOUTHWEST IOWA...

* UNTIL 815 PM CDT

* AT 724 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS
  STORM WAS LOCATED NEAR ATLANTIC...AND MOVING NORTHEAST AT 25 MPH.

* LOCATIONS IMPACTED INCLUDE...
  WIOTA...BRAYTON...ANITA AND EXIRA.

THIS INCLUDES INTERSTATE 80 BETWEEN MILE MARKERS 50 AND 73.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO AN INTERIOR ROOM AND STAY AWAY FROM WINDOWS. IF YOU ARE IN A
MOBILE HOME...GET OUT NOW...AND SEEK SHELTER IN A REINFORCED
BUILDING.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...DEADLY CLOUD TO GROUND
LIGHTNING IS OCCURRING CONTINUOUSLY WITH THIS STORM.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN DES MOINES.

&&

LAT...LON 4152 9511 4151 9510 4151 9505 4155 9504
      4168 9475 4161 9474 4160 9470 4139 9470
      4119 9515 4150 9516
TIME...MOT...LOC 0025Z 236DEG 21KT 4143 9495
WIND...HAIL <50MPH 1.00IN

$$

VACHALEK

2 follow-up statements

849 
WWUS53 KDMX 300047
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
747 PM CDT THU MAR 29 2012

IAC009-029-300115-
/O.CON.KDMX.SV.W.0003.000000T0000Z-120330T0115Z/
AUDUBON IA-CASS IA-
747 PM CDT THU MAR 29 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHWESTERN
CASS AND SOUTHEASTERN AUDUBON COUNTIES UNTIL 815 PM CDT...

AT 742 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS
STORM WAS LOCATED 15 MILES NORTHEAST OF ATLANTIC...MOVING NORTHEAST
AT 25 MPH.

LOCATIONS IMPACTED INCLUDE...
  MAINLY RURAL AREAS OF SOUTHEASTERN AUDUBON COUNTY.

THIS INCLUDES INTERSTATE 80 BETWEEN MILE MARKERS 50 AND 73.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN DES MOINES.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN DES MOINES.

&&

LAT...LON 4152 9511 4151 9510 4151 9505 4155 9504
      4168 9475 4161 9474 4160 9470 4139 9470
      4119 9515 4150 9516
TIME...MOT...LOC 0047Z 236DEG 21KT 4154 9475
WIND...HAIL <50MPH 1.00IN

$$

VACHALEK

123 
WWUS53 KDMX 300059
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
759 PM CDT THU MAR 29 2012

IAC009-029-300115-
/O.CON.KDMX.SV.W.0003.000000T0000Z-120330T0115Z/
AUDUBON IA-CASS IA-
759 PM CDT THU MAR 29 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHWESTERN
CASS AND SOUTHEASTERN AUDUBON COUNTIES UNTIL 815 PM CDT...

AT 756 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A SEVERE
THUNDERSTORM PRODUCING GOLF BALL SIZE HAIL.  THIS STORM WAS LOCATED 7
MILES SOUTH OF ATLANTIC...MOVING NORTHEAST AT 50 MPH.

IN ADDITION...AT 754 PM GOLF BALL HAIL WAS REPORTED 4 MILES 
NORTHEAST OF GRISWOLD WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
  ATLANTIC...ATLANTIC AIRPORT...MARNE...WIOTA...ANITA...BRAYTON AND
  EXIRA.

THIS INCLUDES INTERSTATE 80 BETWEEN MILE MARKERS 50 AND 73.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE FOR LARGE HAIL AND DEADLY CLOUD TO GROUND LIGHTNING. PEOPLE
OUTSIDE SHOULD MOVE TO A REINFORCED BUILDING AND AWAY FROM WINDOWS.

&&

LAT...LON 4152 9511 4151 9510 4151 9505 4155 9504
      4168 9475 4161 9474 4160 9470 4139 9470
      4119 9515 4150 9516
TIME...MOT...LOC 0058Z 219DEG 42KT 4132 9500
WIND...HAIL <50MPH 1.75IN

$$

SMALL

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 29, 8:13 PM CDT	Severe Thunderstorm Warning	DMX	Adair, Cass	47 min
Mar 29, 8:49 PM CDT	Severe Thunderstorm Warning	DMX	Taylor	44 min
Mar 29, 9:49 PM CDT	Severe Thunderstorm Warning	DMX	Ringgold, Taylor	41 min
Mar 29, 10:49 PM CDT	Severe Thunderstorm Warning	DMX	Decatur, Ringgold	41 min
Mar 30, 6:00 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	17 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.