Alert archive / Wyoming / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 92, NWS Cheyenne, WY

August 2, 1990Goshen County, Platte County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Aug 2, 1990, 3:41 PM MDT for Goshen County, Platte County, Wyoming. It was in force for 61 min.

The area

The counties it named.

The facts

Issued
Aug 2, 1990, 3:41 PM MDT (21:41 UTC)
Expired
Aug 2, 1990, 4:42 PM MDT
In force
61 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

Counties Goshen County, WY, Platte County, WY

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Rapid City, SD (KRAP), launched 12:00Z, 9.7 hours before the alert went out and 261 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 1990-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 337 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 1990-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -28 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
337 J/kg
Mixed-layer CIN
-227 J/kg
Mixed-layer LCL
1804 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-28 m²/s²
0-3 km storm-relative helicity
37 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KCYS 022142
SVRCYS
WYC015-031-022245-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
341 PM MDT THU AUG 2 1990
 
THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  445 PM MDT
FOR PEOPLE IN THE FOLLOWING COUNTIES...
 
IN SOUTHEAST WYOMING
          ...SOUTHERN GOSHEN...SOUTHEASTERN PLATTE
 
AT 340 PM MDT RADAR INDICATED A CLUSTER OF SEVERE THUNDERSTORMS
OVER SOUTHEASTERN PLATTE COUNTY...WITH ONE CELL LOCATED 10 MILES
EAST OF WHEATLAND AND ANOTHER CELL 10 MILES NORTH OF CHUGWATER.
THESE STORMS ARE ABOUT 45 MILES NORTH OF CHEYENNE.  MOVEMENT
WAS SOUTHEAST AT 20 MILES AN HOUR.  THIS WARNING INCLUDES THE
TOWNS OF CHUGWATER...VETERAN...YODER AND HAWK SPRINGS.
 
 
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.
 
THIS IS A DANGEROUS STORM.  IF YOU ARE IN ITS PATH YOU SHOULD
PREPARE FOR DAMAGING WIND IN EXCESS OF 55 MPH...LARGE HAIL...AND
DEADLY LIGHTNING.  PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT STAY AWAY FROM WINDOWS.
EKB

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, Aug 2, 1:36 PM MDT, 2 hours 5 minutes before
WYZ012-016 017-022030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
140 PM MDT THU AUG 2 1990

...STRONG THUNDERSTORMS HAVE BEGUN IN SOUTHEAST WYOMING...

AT 140 PM...RADAR AND SATELLITE SHOWED THUNDERSTORMS ALONG THE
LARAMIE RANGE WEST OF CHEYENNE BETWEEN LARAMIE AND CASPER. NO SEVERE
WEATHER WAS NOTED. HOWEVER...AS THESE THUNDERSTORMS CONTINUE TO
DEVELOP...THEY COULD PRODUCE PEA TO MARBLE SIZED HAIL...HEAVY RAIN
AND WIND GUSTS OF 40 TO 45 MILES AN HOUR...AND DANGEROUS LIGHTNING.

DURING THE NEXT HOUR OR SO...CHEYENNE...CHUGWATER...CASPER AND TOWNS
TO THE EAST WILL COME UNDER THE THUNDERSTORM THREAT.

PEOPLE IN SOUTHEAST WYOMING SHOULD KEEP A WATCHFUL EYE ON THE SKMY
AND SEEK INDOOR SHELTER AS THUNDERSTORMS GET CLOSE. REMEMBER...
LIGHTNING IS A LEADING CAUSE OF WEATHER-RELATED INJURIES AND
FATALITIES.
SANDERS
Special weather statement, Aug 2, 2:14 PM MDT, 1 hour 27 minutes before
WYZ012-016 017-022100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
215 PM MDT THU AUG 2 1990

...THUNDERSTORMS ARE PRODUCING GUSTY WINDS IN SOUTHEAST WYOMING...

AT 200 PM...THUNDERSTORMS MOVING THROUGH CHEYENNE PRODUCED WIND GUSTS
TO 40 MILES AN HOUR. MODERATE RAIN FELL BUT NO HAIL WAS OBSERVED.
HOWEVER...FREQUENT LIGHTNING DID OCCUR. THE STORM WAS MOVING SOUTHEAST
AT 20 MILES AN HOUR.

OTHER THUNDERSTORMS WERE OBSERVED ON RADAR BETWEEN CHEYENNE AND
LARAMIE WITH OTHER SCATTERED STORMS NORTH ALONG INTERSTATE 80 TO THE
WHEATLAND AREA. AT 210 PM ONE OF THESE STRONG THUNDERSTORMS WAS
NORTHWEST OF WHEATLAND MOVING TO THE SOUTHEAST. PEOPLE IN THE
WHEATLAND AREA CAN EXPECT BRIEF HEAVY RAIN...WIND GUSTS TO 40 MPH
AND FREQUENT LIGHTNING FROM NOW UNTIL ABOUT 300 PM MDT.

EVERYONE SHOULD RESPECT LIGHTNING AND THE THREAT OF HAIL AND SHOULD
MOVE IN DOORS WHEN THE STORMS APPROACH.
SANDERS
Special weather statement, Aug 2, 2:58 PM MDT, 43 minutes before
WYZ012-016 017-022130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
300 PM MDT THU AUG 2 1990

...SCATTERED THUNDERSTORMS ARE CONTINUING OVER SOUTHEAST WYOMING...

AT 300 PM MDT...THUNDERSTORMS WERE SCATTERED ALONG INTERSTATE 25
BETWEEN CHEYENNE AND CASPER. THE STORNGEST STORMS WERE ABOUT 10 MILES
NORTH OF CHEYENNE AND ANOTHER WAS JUST MOVING OVER WHEATLAND. THEY
WERE MOVING SOUTHEAST AT 15 TO 20 MILES AN HOUR.

RADAR INDICATES THAT THESE THUNDERSTORMS ARE CAPABLE OF PRODUCING
PEA TO MARBLE-SIZED HAIL...WIND GUSTS TO 40 MILES AN HOUR...DEADLY
LIGHTNING AND LOCALLY HEAVY RAIN.

OVER THE NEXT HOUR...THESE THUNDERSTORMS WILL BE MOVING INTO GOSHEN
AND EAST LARAMIE COUNTIES WHICH ARE ALONG THE NEBRASKA BORDER IN
SOUTHEAST WYOMING.
<
KEEP A WATCHFULL AND RESPECTFULL EYE ON THESE THUNDERSTORMS AND SEEK
INDOOR SHELTER AS THESE STORMS APPROACH.
CAS

Nearby

Severe Thunderstorm Warnings in Wyoming, 1990Every severe thunderstorm warning in 1990

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.