Alert archive / Wyoming / Tornado Warnings in 1991

Tornado Warning 29, NWS Cheyenne, WY

June 21, 1991Albany County, Wyoming

NWS Cheyenne, WY issued this tornado warning at Jun 21, 1991, 5:22 PM MDT for Albany County, Wyoming. It was in force for 38 min.

The area

The counties it named.

The facts

Issued
Jun 21, 1991, 5:22 PM MDT (23:22 UTC)
Expired
Jun 21, 1991, 6:00 PM MDT
In force
38 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Albany County, WY

The nearest sounding before it

Lander/Hunt Fiel, WY (KLND), launched 12:00Z, 11.4 hours before the alert went out and 277 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 1991-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 324 joules per kilogram.LCLLFCEL10008507005003002001001 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 1991-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 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
324 J/kg
Mixed-layer CIN
-214 J/kg
Mixed-layer LCL
908 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
84 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 212325
TORCYS
WYC001-220000-
 
BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
522 PM MDT FRI JUN 21 1991
 
THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL  600 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHEAST WYOMING
 
   ...CENTRAL ALBANY COUNTY
THIS INCLUDES THE TOWN OF BOSLER.
AT 510 PM MDT A TORNADO WAS REPORTED BY A MOTORIST WITH A MOBILE
PHONE JUST WEST OF BOSLER. THE SEVERE THUNDERSTORM WARNING FOR THE
BOSLER AREA HAS BEEN UPGRADED TO A TORNADO WARNING.
 
PEOPLE IN BOSLER SHOULD SEEK INDOOR SHELTER IMMEDIATELY.
 
IF YOU ARE IN THE PATH OF A TORNADO...THE SAFEST PLACE IS A
BASEMENT.  GET UNDER A WORKBbENCH OR PIECE OF STURDY FURNITURE.
IF NO BASEMENT IS AVAILABLE...SEEK SHELTER IN AN INTERIOR ROOM
SUCH AS A CLOSET ON THE LOWEST FLOOR.  USE BLANKETS...PILLOWS...
OR CUSHIONS TO COVER YOUR BODY.  AVOID WINDOWS.
 
CAS

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, Jun 21, 1:02 PM MDT, 4 hours 20 minutes before
WYZ005-006-011-012-016-017-212100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
100 PM MDT FRI JUN 21 1991

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR MOST OF EASTERN WYOMING
UNTIL 800 PM MDT THIS EVENING...

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WATCH...
VALID UNTIL 800 PM MDT THIS EVENING...FOR MOST OF EASTERN WYOMING.
THIS MEANS THAT CONDITIONS ARE FAVORABLE IN THE WATCH AREA FOR THE
DEVELOPMENT OF SEVERE THUNDERSTORMS WHICH PRODUCE LARGE HAIL...DAMAGING
WINDS...FREQUENT LIGHTNING...AND HEAVY RAIN.

THE FOLLOWING COUNTIES IN EASTERN WYOMING ARE INCLUDED IN THE WATCH
AREA...SHERIDAN...CAMPBELL...JOHNSON...CONVERSE...PLATTE...ALBANY...
NIOBRARA...GOSHEN...LARAMIE...WESTERN CROOK...WESTERN WESTON...AND
EASTERN NATRONA.

SOME WYOMING TOWNS AND CITIES INCLUDED IN THE WATCH ARE...SHERIDAN
...LUSK...BUFFALO...LARAMIE...GILLETTE...WHEATLAND...MOORCROFT...
TORRINGTON...CASPER...CHEYENNE...PINE BLUFFS...AND DOUGLAS.

PEOPLE IN EASTERN WYOMING ARE URGED TO KEEP ABREAST OF THE LATEST
WEATHER DEVELOPMENTS.  IF THREATENING WEATHER APPROACHES...MOVE TO
A SAFE SHELTER IMMEDIATELY.

VIRGILLITO
Special weather statement, Jun 21, 2:04 PM MDT, 3 hours 18 minutes before
WYZ016-212104-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
204 PM MDT FRI JUN 21 1991

...STRONG THUNDERSTORMS WERE DEVELOPING BETWEEN THE LARAMIE AND SNOWY
RANGES IN SOUTHEASTERN WYOMING...

AT 155 PM MDT...NATIONAL WEATHER SERVICE RADAR INDICATED STRONG
THUNDERSTORMS IN EAST CENTRAL CARBON COUNTY.  THE STRONGEST CELL
WAS LOCATED 45 MILES NORTHWEST OF LARAMIE...WHICH IS APPROXIMATELY
10 MILES NORTH OF ARLINGTON.  THE STORMS WERE MOVING NORTHWEST AT
20 MILES AN HOUR.

THESE THUNDERSTORMS WILL LIKELY PRODUCE HEAVY RAIN...PEA SIZED HAIL
...FREQUENT LIGHTNING...AND STRONG WINDS.  IF THIS STORM APPROACHES
...MOVE TO A SAFE SHELTER IMMEDIATELY.

PEOPLE IN EASTERN WYOMKING ARE ALSO REMINDED THAT A SEVERE THUNDERSTORM
WATCH REMAINS IN EFFECT UNTIL 800 PM MDT THIS EVENING.

VIRGILLITO
Special weather statement, Jun 21, 3:19 PM MDT, 2 hours 3 minutes before
WYZ016-212220-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
318 PM MDT FRI JUN 21 1991

...THUNDERSTORMS CONTINUED TO DEVELOP BETWEEN THE LARAMIE AND SNOWY
RANGES IN SOUTHEASTERN WYOMING...

AT 310 PM MDT...THUNDERSTORMS CONTINUED TO DEVELOP IN EAST CENTRAL
CARBON COUNTY AND WEST CENTRAL ALBANY COUNTY.  THE STRONGEST CELL WAS
LOCATED BETWEEN ARLINGTON AND ROCK RIVER...WHICH IS APPROXIMATELY 38
MILES NORTHWEST OF LARAMIE.  THESE STORMS WERE SHOWING LITTLE IF ANY
MOVEMENT.

THESE THUNDERSTORMS WILL LIKELY PRODUCE HEAVY RAIN...PEA SIZED HAIL
...FREQUENT LIGHTNING...AND STRONG WINDS.  FLOODING OF LOW LYING
AREAS AND ROADS IS ALSO LIKELY DUE TO THE SLOW MOVEMENT OF THESE
STORMS.  IF THESE STORMS APPROACH YOU...MOVE TO A SAFE SHELTER
IMMEDIATELY.
<
PEOPLE IN EASTERN WYOMING ARE ALSO REMINDED THAT A SEVERE THUNDERSTORM
WATCH REMAINS IN EFFECT UNTIL 800 PM MDT THIS EVENING.

VIRGILLITO
Special weather statement, Jun 21, 3:41 PM MDT, 1 hour 41 minutes before
WYZ017-212240-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
340 PM MDT FRI JUN 21 1991

...A STRONG THUNDERSTORM WAS MOVING INTO SOUTH CENTRAL LARAMIE COUNTY
FROM COLORADO...

AT 335 PM MDT...RADAR INDICATED A STRONG THUNDERSTORM ALONG THE
COLORADO/WYOMING BORDER ABOUT 10 MILES SOUTHWEST OF CHEYENNE.  THIS
STORM WAS MOVING NORTHEAST AT 15 MILES AN HOUR AND WILL REACH THE
SOUTHERN OUTSKIRTS OF CHEYENNE BY 350 PM MDT.

PEOPLE IN CHEYENNE AND THE SURROUNDING AREA CAN EXPECT HEAVY RAIN...
PEA SIZED HAIL...FREQUENT LIGHTNING...AND STRONG WINDS AS THIS STORM
MOVES THROUGH THE CITY.  BE PREPARED TO MOVE TO A SAFE SHELTER AS THIS
STORM MAY INTENSIFY.

VIRGILLITO
Special weather statement, Jun 21, 3:45 PM MDT, 1 hour 37 minutes before
WYZ017-212240-

SPECIAL WEATHER STATEMENT...CORRECTED
NATIONAL WEATHER SERVICE CHEYENNE WY
345 PM MDT FRI JUN 21 1991

...A STRONG THUNDERSTORM WAS MOVING INTO SOUTH CENTRAL LARAMIE COUNTY
FROM COLORADO...

AT 335 PM MDT...RADAR INDICATED A STRONG THUNDERSTORM ALONG THE
COLORADO/WYOMING BORDER ABOUT 10 MILES SOUTHWEST OF CHEYENNE.  THIS
STORM WAS MOVING NORTHEAST AT 15 MILES AN HOUR AND WILL REACH THE
SOUTHERN OUTSKIRTS OF CHEYENNE BY 350 PM MDT.

PEOPLE IN CHEYENNE AND THE SURROUNDING AREA CAN EXPECT HEAVY RAIN...
PEA SIZED HAIL...FREQUENT LIGHTNING...AND STRONG WINDS AS THIS STORM
MOVES THROUGH THE CITY.  BE PREPARED TO MOVE TO A SAFE SHELTER AS THIS
STORM MAY INTENSIFY.

PEOPLE IN EASTERN WYOMING ARE ALSO REMINDED THAT A SEVERE THUNDERSTORM
WATCH REMAINS IN EFFECT UNTIL 800 PM MDT THIS EVENING.

CORRECTED TO INCLUDE SEVERE THUNDERSTORM WATCH

VIRGILLITO

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 20, 6:15 PM MDTSevere Thunderstorm WarningCYSPlatte30 min
Jun 21, 5:16 PM MDTSevere Thunderstorm WarningCYSAlbany29 min
Jun 21, 5:17 PM MDTSevere Thunderstorm WarningCYSWashakie43 min

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.