Alert archive / Wyoming / Tornado Warnings in 1991

Tornado Warning 1, NWS Cheyenne, WY

May 2, 1991Sweetwater County, Wyoming

NWS Cheyenne, WY issued this tornado warning at May 2, 1991, 4:52 PM MDT for Sweetwater County, Wyoming. It was in force for 23 min.

The area

The counties it named.

The facts

Issued
May 2, 1991, 4:52 PM MDT (22:52 UTC)
Expired
May 2, 1991, 5:15 PM MDT
In force
23 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Sweetwater County, WY

The nearest sounding before it

Lander/Hunt Fiel, WY (KLND), launched 12:00Z, 10.9 hours before the alert went out and 130 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, Lander/Hunt Fiel, WY at 12:00Z on 1991-05-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lander/Hunt Fiel, WY at 12:00Z on 1991-05-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -93 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
949 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
-93 m²/s²
0-3 km storm-relative helicity
142 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KCYS 022253
TORCYS
WYC037-022315-
 
BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
452 PM MDT THU MAY 2 1991
 
THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL  515 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHWEST WYOMING
 
   ...NORTHWESTERN SWEETWATER COUNTY
 
AT 436PM THIS AFTERNOON SEARCH AND RESCUE PERSONNEL REPORTED A TORNADO
NEAR FONTENELLE IN NORTHEAST LINCOLN COUNTY...OR ABOUT 40 MILES WEST
OF FARSON WHICH IS IN NORTHWEST SWEETWATER COUNTY. THE TORNADO WAS
MOVING EAST.
 
 
 
 
DO NOT USE YOUR CAR TO TRY TO OUTRUN A TORNADO.  CARS ARE EASILY
TOSSED AROUND BY TORNADO WINDS.  IF YOU ARE CAUGHT IN THE PATHe OF
A TORNADO...LEAVE THE CAR AND GO TO A STRONG BUILDING.  IF NO
STRUCTURE IS NEARBY...SEEK SHELTER IN A DITCH OR LOW SPOT.
 
CGB

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, May 2, 12:49 PM MDT, 4 hours 3 minutes before
WYZ001-002-004-005-007-009-022035-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
1245 PM MDT THU MAY 2 1991

...A WINTER STORM WARNING COMTINUES FOR THE WESTERN MOUNTAINS THIS
AFTERNOON AND TONIGHT AS WELL AS A WINTER STORM WATCH FOR THE NORTH
CENTRAL MOUNTAINS FOR TONIGHT...

A LARGE SPRING STORM WAS CENTERED OVER UTAH AND NEVADA EARLY THIS
AFTERNOON. THIS STORM WILL MOVE SLOWLY EAST THROUGH FRIDAY AND WILL
SPREAD SNOW OVER THE MOUNTAINS AND RAIN OR SNOW AT THE LOWER
ELEVATIONS. A WINTER STORM WARNING REMAINS IN EFFECT FOR THE WESTERN
MOUNTAINS THROUGH TONIGHT AND A WINTER STORM WATCH IS IN EFFECT FOR
TONIGHT FOR THE BIG HORN MOUNTAINS.

AT NOON LIGHT SNOW CONTINUED AT TIMES IN THE WESTERN MOUNTAINS. DURING
THE MORNING HOURS...MAMMOTH IN YELLOWSTONE NATIONAL PARK HAS RECEIVED
2 INCHES OF NEW SNOW.
<
SNOW WILL BECOME HEAVY IN THE WESTERN AND NORTHERN MOUNTAINS LATER
THIS AFTERNOON AND TONIGHT. TOTAL SNOWFALL BY SUNRISE FRIDAY WILL BE
8 TO 14 INCHES.

PEOPLE PLANNING TRAVEL OR OUTDOOR ACTIVITIES IN THE WESTERN AND
NORTHERN MOUNTAINS THIS AFTERNOON AND TONIGHT SHOULD BE PREPARED FOR
ADVERSE CONDITIONS. IF YOU MUST TRAVEL OVER THE MOUNTAIN PASSES OF
WESTERN AND NORTH CENTRAL WYOMING...BE PREPARED FOR SNOWPACKED ROADS
AND REDUCED VISIBILITIES THROUGH FRIDAY MORNING.
WEILAND
Special weather statement, May 2, 3:50 PM MDT, 1 hour 2 minutes before
WYZ001-002-004-005-006-007-009-030100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
348 PM MDT THU MAY 2 1991

...WINTER STORM WARNINGS ARE IN EFFECT FOR THE MOUNTAINS OF WESTERN
WYOMING TONIGHT AND FRIDAY...A WINTER STORM WATCH HAS BEEN ISSUED FOR
THE MOUNTAINS OF NORTH CENTRAL AND NORTHEAST WYOMING FOR LATE TONIGHT
AND FRIDAY...

AN INTENSE STORM CONTINUED TO DEVELOP OVER THE GREAT BASIN AND
MOVED SLOWLY EAST.  THE STORM WAS BRINGING SHOWERS AND THUNDERSTORMS
TO NORTHERN UTAH AND SOUTHEAST IDAHO.  THE SHOWERS WERE BEGINNING
TO MOVE INTO WESTERN WYOMING.

HEAVY SNOW WILL BEGIN FALLING TONIGHT IN THE MOUNTAINS OF WESTERN
WYOMING INCLUDING THE TETONS...WIND RIVER...ABSAROKA AND SALT RANGES.
TOTAL NEW SNOW ACCUMULATIONS OF 10 TO 16 INCHES WILL BE LIKELY
IN THESE MOUNTAINS BY FRIDAY AFTERNOON.

AS THE STORM MOVES EAST HEAVY SNOW WILL BE POSSIBLE LATE TONIGHT
AND FRIDAY IN THE BIG HORN MOUNTAINS OF NORTH CENTRAL WYOMING AND
THE BLACK HILLS OF NORTHEAST WYOMING.  ACCUMULATIONS OF 8 TO 12
INCHES WILL BE POSSIBLE BY FRIDAY AFTERNOON IN THE HIGHER ELEVATIONS
WITH 4 TO 8 INCHES POSSIBLE IN THE FOOTHILLS.

PEOPLE PLANNING TRAVEL OR OUTDOOR ACTIVITIES IN THE WESTERN AND
NORTHERN MOUNTAINS TONIGHT AND FRIDAY SHOULD BE PREPARED FOR HEAVY
SNOW. IF YOU MUST TRAVEL OVER THE MOUNTAIN PASSES OF WESTERN AND
NORTHERN WYOMING...BE PREPARED FOR SNOWPACKED ROADS AND REDUCED
VISIBILITIES THROUGH FRIDAY.
SCOTT

Nearby

Tornado Warnings in Wyoming, 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.