Alert archive / Iowa / Tornado Warnings in 1991

Tornado Warning 24, NWS Des Moines, IA

May 27, 1991Mitchell County, Iowa

NWS Des Moines, IA issued this tornado warning at May 27, 1991, 8:14 PM CDT for Mitchell County, Iowa. It was in force for 41 min.

The area

The counties it named.

The facts

Issued
May 27, 1991, 8:14 PM CDT (01:14 UTC)
Expired
May 27, 1991, 8:55 PM CDT
In force
41 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Mitchell County, IA

The nearest sounding before it

Minneapolis, MN (KSTC), launched 00:00Z, 1.2 hours before the alert went out and 178 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, Minneapolis, MN at 00:00Z on 1991-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 806 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, Minneapolis, MN at 00:00Z on 1991-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -15 square meters per square second.1939587897Sfc1 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
806 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
1288 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
-15 m²/s²
0-3 km storm-relative helicity
59 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.8

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KALO 280115
TORALO
IAC131-280215-
 
BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE WATERLOO IA
814 PM CDT MON MAY 27 1991
 
THE NATIONAL WEATHER SERVICE IN WATERLOO HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL  915 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN NORTH CENTRAL IOWA
 
   ...MITCHELL COUNTY
 
AT 800 PM CDT NUMEROUS REPORTS OF FUNNEL CLOUDS WERE REPORTED IN
MITCHELL COUNTY...JUST SOUTH OF ST ANSGAR...25 MILES NORTHEAST OF MASON
CITY AND WEST OF OSAGE...ABOUT 25 MILES EAST OF MASON CITY.
 
AT 800 PM WATERLOO RADAR SHOWED A INTENSE THUNDERSTORM OVER MITCHELL
COUNTY MOVING NORTHEAST AT 15 MILES AN HOUR.
 
DURING A TORNADO...THE SAFEST PLACE IS IN A BASEMENT.   GET UNDER
A WORKBENCH OR PIECE OF STURDY FURNITURE.  IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER IN AN INTERIOR ROOM SUCH AS A CLOSET ON
THE LOWEST FLOOR.  AVOID WINDOWS.

The office that day

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

IssuedProductOfficeCountiesLasted
May 28, 12:04 AM CDTSevere Thunderstorm WarningDMXCarroll41 min
May 28, 12:52 AM CDTSevere Thunderstorm WarningDMXCrawford44 min
May 28, 3:26 AM CDTSevere Thunderstorm WarningDMXWebster49 min
May 28, 3:58 AM CDTSevere Thunderstorm WarningDMXHamilton, Wright47 min
May 28, 4:18 AM CDTSevere Thunderstorm WarningDMXFranklin57 min
May 28, 4:29 AM CDTSevere Thunderstorm WarningDMXHardin46 min
May 28, 5:09 AM CDTSevere Thunderstorm WarningDMXButler, Grundy51 min
May 28, 5:30 AM CDTSevere Thunderstorm WarningDMXBlack Hawk, Bremer30 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.