Alert archive / Iowa / Severe Thunderstorm Warnings in 1996

Severe Thunderstorm Warning 91, NWS Sioux Falls, SD

June 20, 1996Plymouth County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jun 20, 1996, 8:31 PM CDT for Plymouth County, Iowa. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jun 20, 1996, 8:31 PM CDT (01:31 UTC)
Expired
Jun 20, 1996, 9:05 PM CDT
In force
34 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Plymouth County, IA

The radar

The Sioux Falls radar (KFSD), 103 km from the middle of the area, began a volume at 01:35 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 1.5 hours before the alert went out and 158 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 1996-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2363 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 00:00Z on 1996-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 112 square meters per square second.193958Sfc1 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
2363 J/kg
Mixed-layer CIN
-22 J/kg
Mixed-layer LCL
1424 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
112 m²/s²
0-3 km storm-relative helicity
276 m²/s²
Significant tornado parameter
2.1
Supercell composite
19.6

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFSD 210130
SVRFSD
IAC149-210205-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
831 PM CDT THU JUN 20 1996

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS SD HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 905 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN NORTHWEST IOWA

   ...CENTRAL AND EASTERN PLYMOUTH COUNTY
 
AT 829 PM CDT...A SEVERE THUNDERSTORM WAS INDICATED BY SIOUX FALLS
DOPPLER RADAR 17 MILES NORTHEAST OF SIOUX CITY OR NEAR LE MARS
MOVING EAST AT 25 MPH.

THIS STORM CAN BE EXPECTED IN THE VICINITY OF...
UNION CENTER AND OLEARY              AROUND 845 PM CDT

REMEMBER SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES. 

HEITKAMP

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 20, 7:17 PM CDTSevere Thunderstorm WarningFSDCherokee33 min
Jun 20, 7:42 PM CDTSevere Thunderstorm WarningFSDBuena Vista33 min
Jun 20, 11:06 PM CDTFlash Flood WarningFSDPlymouth114 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1996Every severe thunderstorm warning in 1996

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; radar from the NEXRAD Level II archive.