Alert archive / Nebraska / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 45, NWS Cheyenne, WY

May 19, 1991Sioux County, Nebraska

NWS Cheyenne, WY issued this severe thunderstorm warning at May 19, 1991, 7:57 PM MDT for Sioux County, Nebraska. It was in force for 28 min.

The area

The counties it named.

The facts

Issued
May 19, 1991, 7:57 PM MDT (01:57 UTC)
Expired
May 19, 1991, 8:25 PM MDT
In force
28 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Sioux County, NE

The nearest sounding before it

Rapid City, SD (KRAP), launched 00:00Z, 2.0 hours before the alert went out and 190 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, Rapid City, SD at 00:00Z on 1991-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3278 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, Rapid City, SD at 00:00Z on 1991-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 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
3278 J/kg
Mixed-layer CIN
-61 J/kg
Mixed-layer LCL
1043 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
25 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.3

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.

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.

In the hours before

Special weather statement, May 19, 5:03 PM MDT, 2 hours 54 minutes before
WYZ006-011-012-017-200000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
505 PM MDT SUN MAY 19 1991

...A TORNADO WATCH HAS BEEN POSTED FOR NORTHEAST AND EAST CENTRAL
WYOMING UNTIL 11 PM...WITH A SEVERE THUNDERSTORM WATCH UNTIL 11 PM
IN THE FAR SOUTHEAST...

CONDITIONS ONCE AGAIN WERE RIPE FOR SEVERE THUNDERSTORMS OVER MUCH OF
EASTERN WYOMING LATE THIS SUNDAY AFTERNOON INTO THIS EVENING.  HAIL...
STRONG DAMAGING WINDS...AND qPOSSIBLY EVEN A TORNADO COULD OCCUR WITH
A FEW OF THE STORMS.

PEOPLE IN EASTERN WYOMING SHOULD BE ALERT TO THE WEATHER CONDITIONS IN
YOUR AREA...AND MONITOR THIS RADIO STATION FOR FURTHER INFORMATION AND
POSSIBLE WARNINGS.

JAD

The office that day

Everything else NWS Cheyenne, WY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 20, 3:50 PM MDTSevere Thunderstorm WarningCYSScotts Bluff25 min
May 20, 4:09 PM MDTSevere Thunderstorm WarningCYSSioux51 min
May 20, 4:57 PM MDTSevere Thunderstorm WarningCYSMorrill33 min
May 19, 6:32 PM MDTTornado WarningCYSGoshen58 min
May 19, 6:45 PM MDTSevere Thunderstorm WarningCYSGoshen45 min

Nearby

Severe Thunderstorm Warnings in Nebraska, 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.