Alert archive / Iowa / Tornado Warnings in 1991

Tornado Warning 33, NWS Des Moines, IA

September 13, 1991Winnebago County, Iowa

NWS Des Moines, IA issued this tornado warning at Sep 13, 1991, 8:37 PM CDT for Winnebago County, Iowa. It was in force for 38 min.

The area

The counties it named.

The facts

Issued
Sep 13, 1991, 8:37 PM CDT (01:37 UTC)
Expired
Sep 13, 1991, 9:15 PM CDT
In force
38 min
Issued by
NWS Des Moines, IA
Area
Whole counties

County Winnebago County, IA

The nearest sounding before it

Minneapolis, MN (KSTC), launched 00:00Z, 1.6 hours before the alert went out and 164 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 1991-09-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 1991-09-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
NaN m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
192 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KALO 140137
TORALO
IAC189-140215-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING 
NATIONAL WEATHER SERVICE WATERLOO IA
837 PM CDT FRI SEP 13 1991

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 915 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY

   IN THE NORTH CENTRAL PART OF IOWA
      WINNEBAGO

AT 830 PM WEATHER SERVICE RADAR INDICATED A POSSIBLE TORNADO 25
MILES NORTHWEST OF MASON CITY OR JUST EAST OF BUFFALO CENTER.
THE TORNADO WAS MOVING TO THE EAST AT 20 MPH AND WILL BE AFFECTING
THE TOWNS OF THOMPSON...LELAND AND LAKE MILLS.

IF YOU LIVE IN A MOBILE HOME...ABANDON IT AT ONCE FOR A
REINFORCED BUILDING.  IF YOU LIVE IN AN APARTMENT...SEEK SHELTER
IN THE INNERMOST PART OF THE BUILDING ON THE LOWEST FLOOR.

NAME

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.