Alert archive / Nebraska / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 34, NWS Sioux Falls, SD

June 20, 1997Dakota County, Nebraska

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jun 20, 1997, 9:53 PM CDT for Dakota County, Nebraska. It was in force for 47 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, 1997, 9:53 PM CDT (02:53 UTC)
Expired
Jun 20, 1997, 10:40 PM CDT
In force
47 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Dakota County, NE

The radar

The Omaha radar (KOAX), 120 km from the middle of the area, began a volume at 02:55 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, 2.9 hours before the alert went out and 120 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 1997-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 5994 joules per kilogram.LCLEL10008507005003002001001 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 1997-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 89 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
5994 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
1151 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
89 m²/s²
0-3 km storm-relative helicity
186 m²/s²
Significant tornado parameter
4.8
Supercell composite
25.7

Open this sounding in Storm Lab

The text

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

389 
WUUS1 KFSD 210254 RRA
SVRFSD
NEC043-210340-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
953 PM CDT FRI JUN 20 1997

* SEVERE THUNDERSTORM WARNING FOR
  SOUTHERN DIXON COUNTY - IN NORTHEASTERN NEBRASKA

* UNTIL 1040 PM CDT
 
* SOME AREAS AFFECTED
  JACKSON                  AROUND 1030 PM CDT
  WILLIS                   AROUND 1030 PM CDT

* AT 952 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A SEVERE THUNDERSTORM 29 MILES SOUTHWEST OF SIOUX CITY  OR 18
MILES   SOUTHWEST OF WILLIS MOVING NORTHEAST AT 30 MPH.
 
IF YOU ARE OUTDOORS...MOVE TO A PLACE OF SHELTER IMMEDIATELY IF A
STORM APPROACHES.  MOTORISTS SHOULD REMAIN ALERT FOR REDUCED
VISIBILITIES DURING DOWNPOURS OF RAIN.  STREETS MAY FLOOD QUICKLY.

REM

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Sioux Falls, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 20, 9:06 PM CDT, 47 minutes earlier.

Area forecast discussion, Jun 20, 9:06 PM CDT, 47 minutes before
SOUTH DAKOTA/NORTHWEST IOWA/SOUTHWEST MINNESOTA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
905 PM CDT FRI JUN 20 1997

GOING INTO SEVERE WEATHER MODE WITH AN ACTIVE WARNING.  NO SIGNIFICANT
UPDATE FOR THE CWA FROM EARLIER ZONE FORECASTS.

.FSD...NONE
UMLAND

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 20, 10:16 PM CDTSevere Thunderstorm WarningFSDDakota34 min

Nearby

Severe Thunderstorm Warnings in Nebraska, 1997Every severe thunderstorm warning in 1997

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.