Alert archive / Iowa / Severe Thunderstorm Warnings in 1996

Severe Thunderstorm Warning 177, NWS Sioux Falls, SD

August 6, 1996Lyon County, Sioux County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 6, 1996, 9:29 PM CDT for Lyon County, Sioux County, Iowa. It was in force for 31 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
Aug 6, 1996, 9:29 PM CDT (02:29 UTC)
Expired
Aug 6, 1996, 10:00 PM CDT
In force
31 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

Counties Lyon County, IA, Sioux County, IA

The radar

The Sioux Falls radar (KFSD), 59 km from the middle of the area, began a volume at 02:31 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, 2.5 hours before the alert went out and 213 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 1996-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2729 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 1996-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 150 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
2729 J/kg
Mixed-layer CIN
-97 J/kg
Mixed-layer LCL
1384 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
235 m²/s²
Significant tornado parameter
0.9
Supercell composite
6.2

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFSD 070231 COR
SVRFSD
IAC119-167-070300-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING...CORRECTED
NATIONAL WEATHER SERVICE SIOUX FALLS SD
929 PM CDT TUE AUG 6 1996

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS SD HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1000 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN NORTHWEST IOWA

   ...LYON COUNTY
   ...NORTHERN SIOUX COUNTY
 
AT 927 PM CDT...A LINE OF SEVERE THUNDERSTORMS PRODUCING DAMAGING
WINDS WAS INDICATED BY SIOUX FALLS DOPPLER RADAR 26 MILES SOUTHEAST
OF SIOUX FALLS  OR IN THE VICINITY ALVORD MOVING EAST AT 35 MPH.

THIS STORM CAN BE EXPECTED IN THE VICINITY OF...
DOON                     AROUND 935 PM CDT
EDNA                     AROUND 945 PM CDT
GEORGE                   AROUND 950 PM CDT
BOYDEN                   AROUND 955 PM CDT
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH...
DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.  FOR YOUR
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS.

A TORNADO WATCH IS IN EFFECT FOR THE WARNED AREA.  SEVERE
THUNDERSTORMS CAN AND OFTEN DO PRODUCE TORNADOES WITH LITTLE OR NO
ADVANCE WARNING.

CHAPMAN

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 6, 8:57 PM CDTSevere Thunderstorm WarningFSDLyon33 min
Aug 6, 9:43 PM CDTSevere Thunderstorm WarningFSDO'Brien, Osceola32 min
Aug 6, 10:00 PM CDTSevere Thunderstorm WarningFSDWoodbury45 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.