Alert archive / Iowa / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 24, NWS Des Moines, IA

April 26, 1991Carroll County, Crawford County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Apr 26, 1991, 6:39 PM CDT for Carroll County, Crawford County, Iowa. It was in force for 35 min.

The area

The counties it named.

The facts

Issued
Apr 26, 1991, 6:39 PM CDT (23:39 UTC)
Expired
Apr 26, 1991, 7:14 PM CDT
In force
35 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Carroll County, IA, Crawford County, IA

The nearest sounding before it

Omaha, NE (KOVN), launched 12:00Z, 11.7 hours before the alert went out and 131 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-pSkew-T log-p diagram, Omaha, NE at 12:00Z on 1991-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 21 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 1991-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 531 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
21 J/kg
Mixed-layer CIN
-435 J/kg
Mixed-layer LCL
562 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
531 m²/s²
0-3 km storm-relative helicity
672 m²/s²
Significant tornado parameter
0.0
Supercell composite
8.7

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 26, 3:06 PM CDT, 3 hours 33 minutes before
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Special weather statement, Apr 26, 3:09 PM CDT, 3 hours 30 minutes before
IAZALL-262035-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
255 PM CDT FRI APR 26 1991

AT 235 PM...SCATTERED SHOWERS AND THUNDERSTORMS  WERE LOCATED OVER THE
NORTHERN TWO TIERS OF IOWAS COUNTIES...FROM ESTHERVILLE TO 10 MILES
NORTHWEST OF WAUKON...WAUKON IS 60 MILES NORTHWEST OF DUBUQUE. BRIEF
HEAVY RAIN...FREQUENT DEADLY LIGHTNING AND SMALL HAIL CAN BE
EXPECTED WITH THESE STORMS.

THE SHOWERS AND STORMS WERE MOVING NORTH NORTHEAST AT 25 MILES AN HOUR.

FILLBACH/BARLOW
Special weather statement, Apr 26, 4:40 PM CDT, 1 hour 59 minutes before
IAZALL-262235-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
440 PM CDT FRI APR 26 1991

...A TORNADO WATCH REMAINS IN EFFECT FOR PORTIONS OF WESTERN IOWA
   UNTIL 10 PM CDT THIS FRIDAY EVENING.

AT 430 PM...THERE WAS A SMALL RAIN SHOWER LOCATED OVER WEST CENTRAL
IOWA...ABOUT 40 MILES SOUTHWEST OF SIOUX CITY.

THIS SHOWER WAS MOVING NORTHEAST AT 35 MILES AN HOUR.

THERE WILL BE OTHER SHOWERS AND THUNDERSTORM?S ENTERING WESTERN IOWA...
FROM EASTERN NEBRASKA DURING THE NEXT HOUR...BETWEEN OMAHA/COUNCIL
BLUFFS AND SIOUX CITY.

JAK/WPM
Special weather statement, Apr 26, 5:07 PM CDT, 1 hour 32 minutes before
IAZALL-262235-

SPECIAL WEATHER STATEMENT AND IOWA WEATHER UPDATE
NATIONAL WEATHER SERVICE DES MOINES IA
508 PM CDT FRI APR 26 1991

...A TORNADO WATCH REMAINS IN EFFECT FOR PORTIONS OF WESTERN IOWA
   UNTIL 10 PM CDT THIS FRIDAY EVENING.

WIDELY SCATTERED RAIN SHOWERS CONTINUED TO SPREAD INTO SOUTHWEST
AND WEST CENTRAL IOWA.

THESE SHOWERS WERE MOVING NORTHEAST AT 45 MILES AN HOUR.

THE OUTLOOK THROUGH 6PM...THE SKY WILL REMAIN CLOUDY TO MOSTLYn
CLOUDY STATEWIDE.  SHOWERS AND THUNDERSTORMS WILL CONTINUE TO
SPREAD INTO SOUTHWEST AND WEST CENTRAL IOWA.  SOME OF THESE STORMS
COULD PRODUCE SOME SMALL HAIL AND BRIEF STRONG GUSTY WIND...AS WELL
AS FREQUENT DANGEROUS LIGHTNING.

JAK/WPM
Special weather statement, Apr 26, 5:34 PM CDT, 1 hour 5 minutes before
IAZALL-262335-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DES MOINES IA
534 PM CDT FRI APR 26 1991

...A TORNADO WATCH REMAINS IN EFFECT FOR PORTIONS OF WESTERN IOWA
   UNTIL 10 PM CDT THIS FRIDAY EVENING.

AT 527 PM CDT...SCATTERED SHOWERS CONTINUED OVER EXTREME WEST
CENTRAL IOWA...BETWEEN COUNCIL BLUFFS/OMAHA AND SIOUX CITY.

THESE SHOWERS WERE MOVING NORTHEAST AT 45 MILES AN HOUR.

JAK/WPM
Special weather statement, Apr 26, 6:06 PM CDT, 33 minutes before
IAZALL-270035-

SPECIAL WEATHER STATEMENT AND IOWA WEATHER UPDATE
NATIONAL WEATHER SERVICE DES MOINES IA
605 PM CDT FRI APR 26 1991

...A TORNADO WATCH REMAINS IN EFFECT FOR MOST OF WESTERN IOWA
   UNTIL MIDNIGHT THIS FRIDAY EVENING.

NUMEROUS SHOWERS CONTINUED OVER WEST CENTRAL IOWA...IN A 45 MILE
WIDE AREA...CENTERED FROM 40 MILES SOUTHEAST OF SIOUX CITY...
TO 15 MILES NORTH OF COUNCIL BLUFFS.

THESE SHOWERS WERE MOVING NORTHEAST AT 45 MILES AN HOUR.

THE OUTLOOK THROUGH 7 PM...IS FOR CONTINUED INCREASING COVERAGE OF
SHOWERS AND THUNDERSTORMS OVER ABOUT THE WEST ONE-THIRD OF IOWA.
THE SKY WILL REMAIN MOSTLY CLOUDY STATEWIDE.

JAK/WPM

Nearby

Severe Thunderstorm Warnings in Iowa, 1991Every 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.