Alert archive / Iowa / Tornado Warnings in 1991

Tornado Warning 13, NWS Des Moines, IA

April 29, 1991Crawford County, Iowa

NWS Des Moines, IA issued this tornado warning at Apr 29, 1991, 1:52 PM CDT for Crawford County, Iowa. It was in force for 53 min.

The area

The counties it named.

The facts

Issued
Apr 29, 1991, 1:52 PM CDT (18:52 UTC)
Expired
Apr 29, 1991, 2:45 PM CDT
In force
53 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Crawford County, IA

The nearest sounding before it

Omaha, NE (KOVN), launched 12:00Z, 6.9 hours before the alert went out and 114 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 1991-04-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 298 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 1991-04-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -139 square meters per square second.1939587897117136Sfc1 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
298 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
732 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
-139 m²/s²
0-3 km storm-relative helicity
-100 m²/s²
Significant tornado parameter
-0.1
Supercell composite
-1.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 291854
TORDSM
IAC047-291945-
 
BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
152 PM CDT MON APR 29 1991
 
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL 245 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN WEST CENTRAL IOWA
 
   ...CRAWFORD COUNTY
 
AT 152 PM...RADAR INDICATED A POSSIBLE TORNADO NEAR THE CRAWFORD...
SHELBY COUNTY LINE...ABOUT 50 MILES NORTHEAST OF COUNCIL BLUFFS.
A FUNNEL CLOUDY WAS REPORTED WITH THIS STORM AT 135 PM THIS
AFTERNOON.
 
THE STORM WAS MOVING NORTH-NORTHEAST AT 40 MILES AN HOUR...AND WILL
BE AFFECTING THE CITIES OF DOWS CITY...BUCK GROVE...AND DENISON.
 
THIS IS A DANGEROUS STORM SITUATION.  ACT QUICKLY.  IF YOU ARE
IN THE PATH OF THIS TORNADO MOVE TO A SHELTER BELOW GROUND IF
AVAILABLE.  OTHERWISE...GO TO A SMALL INTERIOR ROOM ON THE LOWEST
FLOOR POSSIBLE.  AVOID WINDOWS.  ABANDON CARS AND MOBILE HOMES
FOR A REINFORCED BUIZLDING OR GET INTO A DITCH OR CULVERT.
 
BARLOW/TRUETT/BAKER

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 28, 7:05 PM CDTSevere Thunderstorm WarningDMXDecatur40 min
Apr 28, 8:09 PM CDTSevere Thunderstorm WarningDMXDecatur, Wayne51 min
Apr 28, 9:33 PM CDTFlash Flood WarningDMXWayne117 min
Apr 29, 1:25 PM CDTTornado WarningDMXCrawford, Sac35 min
Apr 29, 1:57 PM CDTTornado WarningDMXBuena Vista33 min
Apr 29, 2:19 PM CDTTornado WarningDMXHamilton, Hardin36 min
Apr 29, 2:31 PM CDTTornado WarningDMXPocahontas44 min
Apr 29, 2:40 PM CDTSevere Thunderstorm WarningDMXSac50 min
Apr 29, 3:05 PM CDTTornado WarningDMXPalo Alto40 min
Apr 29, 3:20 PM CDTSevere Thunderstorm WarningDMXWorth40 min
Apr 29, 3:20 PM CDTSevere Thunderstorm WarningDMXCerro Gordo26 min

Nearby

Tornado Warnings in Iowa, 1991Every tornado warning in 1991Tornadoes 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.