Alert archive / Iowa / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 12, NWS Sioux Falls, SD

May 12, 1991Woodbury County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 12, 1991, 10:24 PM CDT for Woodbury County, Iowa. It was in force for 16 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
May 12, 1991, 10:24 PM CDT (03:24 UTC)
Expired
May 12, 1991, 10:40 PM CDT
In force
16 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Woodbury County, IA

What was reported inside it

TimeReportWhereRemark
May 12, 10:30 PM CDTThunderstorm Wind 50Woodbury, IA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Minneapolis, MN (KSTC), launched 00:00Z, 3.4 hours before the alert went out and 337 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 1991-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 926 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 1991-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 square meters per square second.1939Sfc1 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
926 J/kg
Mixed-layer CIN
-54 J/kg
Mixed-layer LCL
1539 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
29 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 Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 12, 7:26 PM CDTSevere Thunderstorm WarningFSDMcCook34 min
May 12, 7:49 PM CDTSevere Thunderstorm WarningFSDLake26 min
May 12, 8:03 PM CDTSevere Thunderstorm WarningFSDMcCook, Minnehaha27 min
May 12, 8:12 PM CDTSevere Thunderstorm WarningFSDBrookings33 min
May 12, 8:47 PM CDTSevere Thunderstorm WarningFSDMinnehaha28 min
May 12, 9:37 PM CDTSevere Thunderstorm WarningFSDDakota, Dixon63 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.