Alert archive / Iowa / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 21, NWS Des Moines, IA

April 17, 1991Dallas County, Guthrie County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Apr 17, 1991, 5:17 PM CDT for Dallas County, Guthrie County, Iowa. It was in force for 38 min.

The area

The counties it named.

The facts

Issued: Apr 17, 1991, 5:17 PM CDT (22:17 UTC)
Expired: Apr 17, 1991, 5:55 PM CDT
In force: 38 min
Issued by: NWS Des Moines, IA
Area: Whole counties

Counties Dallas County, IA, Guthrie County, IA

The nearest sounding before it

Omaha, NE (KOVN), launched 12:00Z, 10.3 hours before the alert went out and 179 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: 1320 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 117 m²/s²
0-3 km storm-relative helicity: 234 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.

000 
TTAA00 KDSM 172218
SVRDSM
IAC049-077-172300-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
517 PM CDT WED APR 17 1991
 
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  600 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN CENTRAL IOWA
 
   ...DALLAS COUNTY
 
IN WEST CENTRAL IOWA
 
   ...SOUTHEASTERN GUTHRIE COUNTY
 
AT 515 PM...WEATHER RADAR INDICATED A SEVERE THUNDERSTORM OVER SOUTH
CENTRAL GUTHRIE COUNTY...ABOUT 10 MILES SOUTH OF GUTHRIE CENTER OR
ABOUT 45 MILES WEST OF DES MOINES.
 
THE STORM WAS MOVING NORTHEAST AT 30 MILES AN HOUR...AND WILL BE
AFFECTING THE CITIES OF PANORA...LINDEN...AND REDFIELD.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60
MPH...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
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.
 
HUTTON/TRUETT

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Apr 17, 2:48 PM CDT, 2 hours 29 minutes before

IAZALL-172040-

RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
2 35PM CDT WED APR 17 1991

AT 2 30PM...AN INTENSE THUNDERSTORM WITH VERY HEAVY RAIN AND HAIL WAS
LOCATED NEAR CHARITON IN SOUTH CENTRAL IOWA.  PEA SIZE HAIL WAS REPORTED
IN CHARITON.

OTHER SHOWERS AND THUNDERSTORMS WERE LOCATED ALONG THE IOWA/MISSOURI
BORDER BETWEEN CLARINDA AND KEOSAUQUA...OR ABOUT 75 MILES SOUTHWEST OF
DES MOINES TO 30 MILES SOUTHEAST OF OTTUMWA.

THE STORMMS WERE MOVING TO THE EAST AT 30 MILES AN HOUR.

SCOTT

Special weather statement, Apr 17, 4:17 PM CDT, 1 hour before

IAZALL-172220-

SPECIAL WEATHER STATEMENT AND WEATHER UPDATE FOR IOWA
NATIONAL WEATHER SERVICE DES MOINES IA
416 PM CDT WED APR 17 1991

AT 410 PM...A VERY STRONG THUNDERSTORM WAS INDICATED 65 MILES SOUTHWEST
OF DES MOINES...JUST SOUTH OF ATLANTIC.  PEA TO MARBLE SIZE HAIL...VERY
HEAVY RAIN AND DEADLY LIGHTNING CAN BE EXPECTED WITH THIS STORM AS IT
MOVES INTO THE CUMBERLAND AREA BY 445PM.

OTHER SCATTERED SHOWERS AND THUNDERSTORMS WERE DEVELOPING OVER SOUTHWEST
IOWA...BOUNDED BY A LAMONI...ADAIR...COUNCIL BLUFFS LINE.

ISOLATED SHOWERS AND THUNDERSTORMS WERE IN SOUTHEAST IOWA...NORTHWEST
OF BURLINGTON.

THE SHOWERS AND THUNDERSTORMS WERE MOVING EAST AT 25 MILES AN HOUR.

THE OUTLOOK THROUGH 6 PM IS FOR INCREASING SHOWERS AND THUNDERSTORMS
OVER PARTS OF THE SOUTHERN HALF OF THE STATE.  SOME STORMS WILL BE
LOCALLY STRONG.

HUTTON

Special weather statement, Apr 17, 4:50 PM CDT, 27 minutes before

IAZALL-172235-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
445 PM CDT WED APR 17 1991

BETWEEN 340 AND 440 THIS AFTERNOON...THUNDERSTORMS DEVELOPED RAPIDLY
OVER SOUTHWEST IOWA.  AT 440 PM...THE STRONGEST STORMS WERE BETWEEN
ATLANTIC AND MOUNT AYR...OR ABOUT 50 TO 60 MILES WEST AND SOUTHWEST OF
DES MOINES.

THESE STORMS WERE MOVING EAST AT 25 MILES AN HOUR...AND WILL BE
AFFECTING THE CRESTON AND GREENFIELD AREAS BETWEEN 445 AND 530 PM.
HEAVY RAINS AND PEA-SIZED HAIL CAN BE EXPECTED WITH THE STORMS PASSAGE.

ISOLATED THUNDERSTORMS WERE ALSO OVER CENTRAL IOWA...BETWEEN DES MOINES
AND CEDAR RAPIDS...AND IN EXTREME SOUTHEAST IOWA...NEAR BURLINGTON.

THESE SHOWERS AND STORMS WERE ALSO MOVING EAST AT 25 MILES AN HOUR.

TRUETT/HUTTON

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 17, 2:40 PM CDT	Severe Thunderstorm Warning	DMX	Lucas, Monroe	50 min
Apr 17, 5:37 PM CDT	Severe Thunderstorm Warning	DMX	Adair	38 min
Apr 17, 6:15 PM CDT	Severe Thunderstorm Warning	DMX	Adair	31 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1991 Every severe thunderstorm warning in 1991

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.