Alert archive / Iowa / Severe Thunderstorm Warnings in 1991
Severe Thunderstorm Warning 29, NWS Des Moines, IA
NWS Des Moines, IA issued this severe thunderstorm warning at Apr 26, 1991, 9:19 PM CDT for Clarke County, Iowa. It was in force for 41 min.
The area
The counties it named.
The facts
- Issued
- Apr 26, 1991, 9:19 PM CDT (02:19 UTC)
- Expired
- Apr 26, 1991, 10:00 PM CDT
- In force
- 41 min
- Issued by
- NWS Des Moines, IA
- Area
- Whole counties
County Clarke County, IA
The nearest sounding before it
Topeka, KS (KTOP), launched 00:00Z, 2.3 hours before the alert went out and 275 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- NaN m above ground
- 0-6 km bulk shear
- 79 kt
- 0-1 km storm-relative helicity
- 409 m²/s²
- 0-3 km storm-relative helicity
- 485 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 17.2
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, 6:42 PM CDT, 2 hours 37 minutes before
IAZALL-270135- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 740 PM CDT FRI APR 26 1991 ...A TORNADO WATCH REMAINS IN EFFECT FOR MOST OF WESTERN IOWA UNTIL MIDNIGHT THIS FRIDAY EVENING. AT 727 PM CDT...VERY STRONG THUNDERSTORMS HAVE DEVELOPED RAPIDLY OVER WEST CENTRAL IOWA. THE STRONGEST STORMS WERE LOCATED IN ABOUT A 20 MILE WIDE AREA...CENTERED FROM NEAR ADAIR...OR 50 MILES WEST OF DES MOINES...TO NEAR MANILLA...OR 50 MILES NORTHEAST OF COUNCIL BLUFFS...TO JUST NORTH OF COUNCIL BLUFFS. THESE STORMS...ALONG WITH BRIEF VERY HEAVY RAINFALL...HAVE BEEN PRODUCING SOME LARGE HAIL...FREQUENT DANGEROUS LIGHTNING...AND COULD ALSO PRODUCE BRIEF STRONG GUSTY WIND. THE STORMS WERE MOVING NORTHEAST AT 45 MILES AN HOUR. . PEOPLE IN THE PATH OF THESE STORMS SHOULD BE PREPARED TO SEEK SHELTER IMMEDIATELY IF THREATENING WEATHER APPROACHES. JAK/WPM
Special weather statement, Apr 26, 7:51 PM CDT, 1 hour 28 minutes before
IAZALL-270135- SPECIAL WEATHER STATEMENT AND RADAR SUMMARY NATIONAL WEATHER SERVICE DES MOINES IA 750 PM CDT FRI APR 26 1991 ...A TORNADO WATCH REMAINS IN EFFECT FOR MOST OF WESTERN IOWA UNTIL MIDNIGHT THIS FRIDAY EVENING. AT 727 PM CDT...INTENSE THUNDERSTORMS WERE LOCATED OVER EXTREME WEST CENTRAL IOWA...IN A 10 MILE WIDE AREA...FROM NEAR MAPLETON...30 MILES SOUTHEAST OF SIOUX CITY...TO JUST NORTH OF COUNCIL BLUFFS. THESE INTENSE STORMS...WERE PRODUCING BRIEF VERY HEAVY RAIN... FREQUENT DANGEROUS LIGHTNING...AND COULD ALSO PRODUCE SOME LARGE HAIL AND STRONG GUSTY WIND. OVER THE REMAINDER OF ABOUT THE WEST HALF OF IOWA...NUMEROUST SHOWERS AND STRONG THUNDERSTORMS CONTINUED TO DEVELOP. THE STORMS WERE MOVING NORTHEAST AT 45 MILES AN HOUR. PEOPLE IN THE PATH OF THESE NUMEROUS STRONG THUNDERSTORMS SHOULD REMAIN ALERT FOR RAPIDLY CHANGING CONDITIONS...AND BE PREPARED TO SEEK SHELTER IMMEDIATELY SHOULD THREATENING WEATHER APP.ROACH. JAK/WPM
Special weather statement, Apr 26, 8:05 PM CDT, 1 hour 14 minutes before
IAZALL-270200- SPECIAL WEATHER STATEMENT AND IOWA WEAHTER UPDATE NATIONAL WEATHER SERVICE DES MOINES IA 805 PM CDT FRI APR 26 1991 ...A TORNADO WATCH REMAINS IN EFFECT FOR MUCH OF THE WEST HALF OF IOWA UNTIL 2 AM SATURDAY MORNING...AND FOR EXTREME NORTHWEST IOWA UNTIL MIDNIGHT THIS FRIDAY EVENING... WIDELY SCATTERED INTENSE THUNDERSTORMS CONTINUED OVER WEST CENTRAL AND SOUTHWEST IOWA. IN WEST CENTRAL IOWA...THE STRONGEST STORMS WERE LOCATED IN ABOUT A 20 MILE WIDE AREA...FROM NEAR DENNISON...OR 45 MILES SOUTHWEST OF SIOUX CITY...TO NEAR SAC CITY...OR 45 MILES WEST OF FORT DODGE. IN SOUTHWEST IOWA...THE STRONGEST STORMS WERE LOCATED IN ABOUT A 10 MILE WIDE BAND...CENTERED FROM JUST NORTHEAST OF VALISCA ...60 MILES SOUTHEAST OF COUNCIL BLUFFS...SOUTH TO THE IOWA/MISSOURI BORDER. OVER THE REMAINDER OF ABOUT THE WEST HALF OF IOWA...NUMEROUS SHOWERS AND STRONG THUNDERSTORMS CONTINUED TO DEVELOP. THESE STORMS WERE MOVING NORTHEAST AT 45 MILES AN HOUR. PEOPLE IN THE PATH OF THESE NUMEROUS STRONG THUNDERSTORMS SHOULD REMAIN ALERT FOR RAPIDLY CHANGING CONDITIONS...AND BE PREPARED TO SEEK SHELTER IMMEDIATELY SHOULD THREATENING WEATHER APPROACH. THE OUTLOOK THROUGH 9 CPM IS FOR CONTINUED STRONG THUNDERSTORMS TO CONTINUED OVER ABOUT THE WEST HALF OF IOWA...WITH A MOSTLY CLOUDY SKY ELSEWHERE. JAK/WPM
Special weather statement, Apr 26, 8:49 PM CDT, 30 minutes before
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</html>Special weather statement, Apr 26, 9:03 PM CDT, 16 minutes before
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</html>The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 26, 7:43 PM CDT | Severe Thunderstorm Warning | DMX | Crawford | 32 min |
| Apr 26, 7:49 PM CDT | Tornado Warning | DMX | Crawford | 26 min |
| Apr 26, 8:19 PM CDT | Tornado Warning | DMX | Sac | 56 min |
| Apr 26, 8:36 PM CDT | Severe Thunderstorm Warning | DMX | Buena Vista | 29 min |
| Apr 26, 8:55 PM CDT | Severe Thunderstorm Warning | DMX | Ringgold | 30 min |
| Apr 26, 9:19 PM CDT | Severe Thunderstorm Warning | DMX | Decatur | 35 min |
| Apr 26, 9:46 PM CDT | Severe Thunderstorm Warning | DMX | Polk, Warren | 44 min |
| Apr 26, 10:59 PM CDT | Severe Thunderstorm Warning | DMX | Lucas, Wayne | 31 min |
| Apr 26, 11:18 PM CDT | Tornado Warning | DMX | Wayne | 27 min |
| Apr 26, 11:23 PM CDT | Tornado Warning | DMX | Lucas | 37 min |
| Apr 27, 12:02 AM CDT | Severe Thunderstorm Warning | DMX | Mahaska, Marion, Monroe | 28 min |
| Apr 27, 1:30 AM CDT | Severe Thunderstorm Warning | DMX | Mahaska | 45 min |
| Apr 27, 2:04 AM CDT | Tornado Warning | DMX | Iowa | 41 min |
| Apr 27, 2:04 AM CDT | Tornado Warning | DMX | Keokuk | 15 min |
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.