Alert archive / Nebraska / Tornado Warnings in 1991

Tornado Warning 40, NWS Cheyenne, WY

September 12, 1991Dawes County, Nebraska

NWS Cheyenne, WY issued this tornado warning at Sep 12, 1991, 6:55 PM MDT for Dawes County, Nebraska. It was in force for 35 min.

The area

The counties it named.

The facts

Issued
Sep 12, 1991, 6:55 PM MDT (00:55 UTC)
Expired
Sep 12, 1991, 7:30 PM MDT
In force
35 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Dawes County, NE

The nearest sounding before it

Rapid City, SD (KRAP), launched 00:00Z, 0.9 hours before the alert went out and 152 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 1991-09-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 741 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 1991-09-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 square meters per square second.1939587897Sfc1 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
741 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
1046 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
103 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KBFF 130055
TORBFF
NEC045-130130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING 
NATIONAL WEATHER SERVICE SCOTTSBLUFF NE
655 PM MDT THU SEP 12 1991

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 730 PM MDT FOR PEOPLE IN THE FOLLOWING 
COUNTIES

   IN THE PANHANDLE OF NEBRASKA
      DAWES...THE CITY OF CHADRON

AT 654 PM MDT...A TORNADO WAS INDICATED BY RADAR 3 MILES WEST OF
CHADRON NEBRASKA MOVING SOUTHEAST AT 20 MPH.

THIS WARNING INCLUDES THE CITY OF CHADRON AND THE CHADRON STATE
PARK RECREATION AREA.

THIS WARNING REPLACES THE SEVERE THUNDERSTPRM WARNING ISSUED AT
627 PM MDT FOR DAWES COUNTY.

IF YOU ARE CAUGHT OUTSIDE...FIND SHELTER IN A NEARBY REINFORCED
BUILDING.  AS A LAST RESORT...TAKE SHELTER IN A CULVERT...DITCH OR
LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

GIVE REPORTS OF SEVERE WEATHER OR DAMAGE TO A LAW ENFORCEMENT AGENCY
FOR RELAY TO THE NATIONAL WEATHER SERVPICE.

PFEIFFER

What forecasters said that day

The local office's own words before this tornado 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, Sep 12, 4:42 PM MDT, 2 hours 13 minutes before
WYZ012-017-122341-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
441 PM MDT THU SEP 12 1991

...STRONG THUNDERSTORMS CONTINUED IN SOUTHEAST WYOMING...

AT 435 PM MDT...STRONG THUNDERSTORMS CONTINUED TO DEVELOP IN THE
SOUTHEAST CORNER OF WYOMING.  THIS AREA OF THUNDERSTORMS COVERED
MOST OF LARAMIE COUNTY AS WELL AS THE SOUTHERN HALF OF PLATTE COUNTY.
THESE STORMS WERE MOVING NORTHEAST AT 20 MILES AN HOUR AND SHOULD
SPREAD INTO GOSHEN COUNTY BY 500 PM MDT.

THE STRONGEST STORMS WERE LOCATED 15 MILES NORTHEAST OF CHEYENNE AND
15 MILES SOUTHEAST OF CHEYENNE.  THESE STORMS PRODUCED PEA SIZED HAIL
...WIND GUSTS TO 40 MILES AN HOUR...BRIEF HEAVY RAIN...AND FREQUENT
LIGHTNING AS THEY MOVED THROUGH THE CITY OF CHEYENNE AROUND 400 PM.

PEOPLE IN THE SOUTHEAST CORNER OF CHEYENNE SHOULD REMAIN ALERT TO THE
POSSIBILITY OF STRONG THUNDERSTORMS THROUGH THE EARLY EVENING HOURS.

IF A STORM APPROACHES YOUR AREA...MOVE TO At SAFE INDOOR SHELTER.

VIRGILLITO
Special weather statement, Sep 12, 4:49 PM MDT, 2 hours 6 minutes before
WYZ012-017-122341-

SPECIAL WEATHER STATEMENT...CORRECTED
NATIONAL WEATHER SERVICE CHEYENNE WY
448 PM MDT THU SEP 12 1991

...STRONG THUNDERSTORMS CONTINUED IN SOUTHEAST WYOMING...

AT 435 PM MDT...STRONG THUNDERSTORMS CONTINUED TO DEVELOP IN THE
SOUTHEAST CORNER OF WYOMING.  THIS AREA OF THUNDERSTORMS COVERED
MOST OF LARAMIE COUNTY AS WELL AS THE SOUTHERN HALF OF PLATTE COUNTY.
THESE STORMS WERE MOVING NORTHEAST AT 20 MILES AN HOUR AND SHOULD
SPREAD INTO GOSHEN COUNTY BY 500 PM MDT.

THE STRONGEST STORMS WERE LOCATED 15 MILES NORTHEAST OF CHEYENNE AND
15 MILES SOUTHEAST OF CHEYENNE.  THESE STORMS PRODUCED PEA SIZED HAIL
...WIND GUSTS TO 40 MILES AN HOUR...BRIEF HEAVY RAIN...AND FREQUENT
LIGHTNING AS THEY MOVED THROUGH THE CITY OF CHEYENNE AROUND 400 PM.

PEOPLE IN THE SOUTHEAST CORNER OF WYOMING SHOULD REMAIN ALERT TO THE
POSSIBILITY OF STRONG THUNDERSTORMS THROUGH THE EARLY EVENING HOURS.
IF A STORM APPROACHES YOUR AREA...MOVE TO A SAFE INDOOR SHELTER.

CORRECTED FOR WORDING LAST PARAGRAPH

VIRGILLITO
Special weather statement, Sep 12, 5:17 PM MDT, 1 hour 38 minutes before
WYZ012-017-130015-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
515 PM MDT THU SEP 12 1991

...THUNDERSTORMS CONTINUED IN SOUTHEAST WYOMING...

AT 510 PM MDT...SCATTERED THUNDERSTORMS WERE NOTED IN PORTIONS OF
SOUTHEAST WYOMING. SHOWERS AND THUNDERSTORMS WERE NOTED IN CENTRAL
AND EASTERN LARAMIE COUNTY AS WELL AS THE SOUTHERN PORTIONS OF GOSHEN
AND PLATTE COUNTIES.  THE STORMS WERE MOVING NORTHEAST AT 20 MILES AN
HOUR.

THE STRONGEST STORM WAS LOCATED 30 MILES NORTHEAST OF CHEYENNE. THIS
STORM COULD PRODUCE BRIEF HEAVY RAIN...SMALL HAIL AND STRONG GUSTY
WINDS AS IT MOVES TO THE EXTREME EASTERN PORTION OF THE LARAMIE COUNTY.

PEOPLE IN THE SOUTHEAST CORNER OF WYOMING SHOULD REMAIN ALERT TO THE
POSSIBILITY OF STRONG THUNDERSTORMS THROUGH THE EARLY EVENING HOURS.
IF A STORM APPROACHES YOUR AREA...MOVE TO A SAFE INDOOR SHELTER.

SIGLER
Special weather statement, Sep 12, 6:14 PM MDT, 41 minutes before
WYZ012-017-130130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
610 PM MDT THU SEP 12 1991

...STRONG THUNDERSTORMS CONTINUE OVER EXTREME SOUTHEAST WYOMING...

AT 600 PM...SEVERAL STORNG THUNDERSTORMS REMAINED OVER THE EXTREME
SOUTHEAST CORNER OF WYOMING. AT THAT TIME THE STRONG STORMS WERE
LOCATED FROM 5 MILES SOUTH OF PINE BLUFFS TO 25 MILES NORTH OF PINE
BLUFFS. THAT AREA IS ABOUT 40 MILES EAST OF CHEYENNE.

AS A STORM MOVED THROUGH LA GRANGE...WHICH IS 29 MILES SOUTH OF
TORRINGTON...MODERATE RAIN FELL. ALL OF THE STORMS WERE MOVING TO THE
NORTHEAST AT 20 MILES AN HOUR...WITH THE STRONG STORMS EXITING WYOMING
BY 645 PM. UNTIL THAT TIME THE STORMS WILL PRODUCE HEAVY RAIN...SMALL
HAIL AND WIND GUSTS TO 40 MILES AN HOUR.

PEOPLE IN THE EXTREME SOUTHEAST CORNER OF WYOMING SHOULD REMAIN ALERT
TO THE POSSIBILITY OF STRONG THUNDERSTORMS THROUGH THE EARLY EVENING
HOURS. IF A STORM APPROACHES...MOVE INDOORS TO A SAFE SHELTER.
WEILAND

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 12, 6:27 PM MDTSevere Thunderstorm WarningCYSDawes63 min
Sep 12, 7:29 PM MDTSevere Thunderstorm WarningCYSDawes26 min

Nearby

Tornado Warnings in Nebraska, 1991Every tornado warning in 1991Tornadoes 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.