Alert archive / Wyoming / Tornado Warnings in 1991

Tornado Warning 8, NWS Cheyenne, WY

May 30, 1991Goshen County, Wyoming

NWS Cheyenne, WY issued this tornado warning at May 30, 1991, 4:00 PM MDT for Goshen County, Wyoming. It was in force for 30 min.

The area

The counties it named.

The facts

Issued
May 30, 1991, 4:00 PM MDT (22:00 UTC)
Expired
May 30, 1991, 4:30 PM MDT
In force
30 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Goshen County, WY

The nearest sounding before it

Rapid City, SD (KRAP), launched 12:00Z, 10.0 hours before the alert went out and 251 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 12:00Z on 1991-05-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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 12:00Z on 1991-05-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 170 square meters per square second.19395878Sfc1 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1552 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
170 m²/s²
0-3 km storm-relative helicity
134 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 302203
TORCYS
WYC015-302230-
 
BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
400 PM MDT THU MAY 30 1991
 
THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL  430 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHEAST WYOMING
 
   ...CENTRAL GOSHEN COUNTY
 
AT 355 PM MDT...A TORNADO WAS REPORTED 10 MILES WEST OF VETERAN
WYOMING IN CENTRAL GOSHEN COUNTY. THIS TORNADO WAS MOVING NORTHEAST AT
25 MILES AN HOUR.
 
THIS IS A DANGEROUS STORM SITUATION.  ACT QUICKLY.  IF YOU ARE
IN THE PATH OF THIS TORNADO MOVE TO A SHELTER BELOW GROUND IF
AVAILABLE.  OTHERWISE...GO TO A SMALL INTERIOR ROOM ON THE LOWEST
FLOOR POSSIBLE.  AV$OID WINDOWS.  ABANDON CARS AND MOBILE HOMES
FOR A REINFORCED BUILDING OR GET INTO A DITCH OR CULVERT.
 
VIRGILLITO

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 30, 3:01 PM MDT, 59 minutes before
WYZ006-012-310000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
300 PM MDT THU MAY 30 1991

...A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR NORTHEAST WYOMING
FOR THIS AFTERNOON AND EVENING...

THUNDERSTORMS HAVE BEGUN TO DEVELOP IN EASTERN WYOMING AGAIN.  THE
STRONGEST STORMS ARE EXPECTED TO FORM OVER NORTHEAST SECTIONS OF THE
STATE.  AS A RESULT...THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE
THUNDERSTORM WATCH VALID FROM 330 PM THIS AFTERNOON UNTIL 900 PM THIS
EVENING.

THE WATCH AREA INCLUDES CROOK...WESTON...NIOBRARA...EASTERN CAMPBELL
...AND EASTERN CONVERSE COUNTIES.

PERSONS IN THOSE COUNTIES ARE ADVISED TO KEEP ABREAST OF THE LATEST
WEATHER DEVELOPMENTS.
<
CGB
Special weather statement, May 30, 3:26 PM MDT, 34 minutes before
WYZ012-302200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
325 PM MDT THU MAY 30 1991

...A STRONG THUNDERSTORM HAS DEVELOPED IN FAR WESTERN GOSHEN COUNTY
IN SOUTHEAST WYOMING AT 320 PM...

THE STORM WAS LOCATED ABOUT 18 MILES SOUTHEAST OF WHEATLAND...AND
MOVING NORTH NORTHEAST AT ABOUT 25 MILES AN HOUR INTO FAR WESTERN
GOSHEN COUNTY.

PEOPLE IN WESTERN GOSHEN COUNTY SHOULD REMAIN ALERT TO THIS STORM...
AS IT LIKELY IS PRODUCING SMALL HAIL...BRIEF HEAVY RAIN...AND GUSTY
WINDS.  GO TO SAFE PLACE SUCH AS YOUR BASEMENT AND WAIT FOR THE
STORM TO PASS.

JAD

The office that day

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

IssuedProductOfficeCountiesLasted
May 30, 3:59 PM MDTSevere Thunderstorm WarningCYSPlatte61 min
May 30, 4:17 PM MDTTornado WarningCYSGoshen, Platte43 min
May 30, 4:58 PM MDTSevere Thunderstorm WarningCYSLaramie47 min
May 30, 5:40 PM MDTTornado WarningCYSLaramie50 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.