Alert archive / Iowa / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 18, NWS Des Moines, IA

April 12, 1991Boone County, Dallas County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Apr 12, 1991, 4:07 AM CDT for Boone County, Dallas County, Iowa. It was in force for 53 min.

The area

The counties it named.

The facts

Issued
Apr 12, 1991, 4:07 AM CDT (09:07 UTC)
Expired
Apr 12, 1991, 5:00 AM CDT
In force
53 min
Issued by
NWS Des Moines, IA
Area
Whole counties

Counties Boone County, IA, Dallas County, IA

The nearest sounding before it

Omaha, NE (KOVN), launched 00:00Z, 9.1 hours before the alert went out and 207 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 00:00Z on 1991-04-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 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 00:00Z on 1991-04-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 435 square meters per square second.19395878Sfc1 km3 km6 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
609 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
435 m²/s²
0-3 km storm-relative helicity
505 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

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.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 12, 3:30 AM CDTSevere Thunderstorm WarningDMXAudubon, Carroll24 min
Apr 12, 10:57 AM CDTSevere Thunderstorm WarningDMXJasper33 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.