Alert archive / Wyoming / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 46, NWS Cheyenne, WY

June 15, 1990Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 15, 1990, 4:42 PM MDT for Laramie County, Wyoming. It was in force for 48 min. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jun 15, 1990, 4:42 PM MDT (22:42 UTC)
Expired
Jun 15, 1990, 5:30 PM MDT
In force
48 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Laramie County, WY

The radar

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

What was reported inside it

TimeReportWhereRemark
Jun 15, 4:45 PM MDTHail 1.75Laramie, WY
Jun 15, 5:05 PM MDTHail 2.5Laramie, WY

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 10.7 hours before the alert went out and 202 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, Denver, CO at 12:00Z on 1990-06-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 810 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, Denver, CO at 12:00Z on 1990-06-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 0 square meters per square second.1939Sfc1 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
810 J/kg
Mixed-layer CIN
-164 J/kg
Mixed-layer LCL
1002 m above ground
0-6 km bulk shear
0 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
0 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 152244
SVRCYS
WYC021-152330-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
442 PM MDT FRI JUN 15 1990
 
THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  530 PM MDT
FOR PEOPLE IN THE FOLLOWING COUNTY...
 
IN SOUTHEAST WYOMING
          ...SOUTHERN LARAMIE
 
GOLF BALL HAIL SIZE WAS REPORTED 7 MILES SOUTH OF CHEYENNE
AT 440 PM MDT. HEAVY RAIN WAS NOTED 4 MILES SOUTH OF
THE CITY OF CHEYENNE.  THE STORMS APPREAR TO MOVING
SLOWLY TO THE EAST.
 
A TORNADO WATCH IS IN EFFECT UNTIL 8 PM MDT FOR SOUTHEAST
WYOMING.
 
THE WATCH AND THE SEVERE THUNDERSTORM WARNING INCLUDES THE
CITY OF CHEYENNE.
 
 
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.
SGS

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, Jun 15, 12:45 PM MDT, 3 hours 57 minutes before
WYZ012-016-017-151945-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
1245 PM MDT FRI JUN 15 1990

A FEW THUNDERSTORMS HAD DEVELOPED OVER SOUTHEAST WYOMING AS OF 1230 PM
MDT.  THE STRONGEST STORM WAS NEAR CHUGWATER OR SOME 40 MILES NORTH OF
CHEYENNE.

ALL OF THE THUNDERSTORMS WERE MOVING NORTHEAST AROUND 25 MILES AN HOUR.

THUNDERSTORMS WILL CONTINUE TO DEVELOP OVER SOUTHEAST WYOMING DURING
THE AFTERNOON.  DUE TO A MOIST AND UNSTABLE AIR MASS...SOME OF THESE
COULD BECOME SEVERE PRODUCING HAIL...STRONG WINDS AND DEADLY LIGHTNING.

PEOPLE IN SOUTHEAST WYOMING SHOULD BE ALERT FOR THUNDERSTORM
DEVELOPMENT THIS AFTERNOON AND EVENING.  KEEP AN EYE ON THE SKY AND
BE READY T1O SEEK A SAFE PLACE SHOULD THREATENING WEATHER APPROACH.

HATTEN
Special weather statement, Jun 15, 1:42 PM MDT, 3 hours before
WYZ012-016-017-152045-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
145 PM MDT FRI JUN 15 1990

...A TORNADO WATCH IS IN EFFECT FOR THE SOUTHEAST CORNER OF WYOMING...

A TORNADO WATCH HAS BEEN ISSUED FOR THE SOUTHEAST BORDER AREA OF
WYOMING FROM 200 PM MDT TO 800 PM MDT. A TORNADO WATCH MEANS CONDITIONS
ARE FAVORABLE FOR TORNADOES.

AT 145 PM MDT SCATTERED THUNDERSTORMS CONTINUED TO DEVELOP IN SOUTHEAST
WYOMING. THE STRONGEST CELL WAS OVER CHUGWATER WHICH IS ABOUT 40 MILES
NORTH OF CHEYENNE. ANOTHER RAPIDLY GROWING CELL WAS JUST TO THE EAST
OF THE CITY OF CHEYENNE. THE STORMS WERE MOVING NORTHEAST AT 25 MILES
AN HOUR.

PEOPLE IN SOUTHEAST WYOMING SHOULD BE ALERT FOR SEVERE THUNDERSTORM
DEVELOPMENT THIS AFTERNOON AND EVENING. SEVERE THUNDERSTORMS CAN
PRODUCE TORNADOES WITH LITTLE ADVANCE WARNING.  KEEP AN EYE ON THE SKY
AND BE READY TO SEEK SHELTER IF THREATENING CONDITIONS ARE SIGHTED.
CAS
Special weather statement, Jun 15, 2:27 PM MDT, 2 hours 15 minutes before
WYZ012-016-017-152055-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
225 PM MDT FRI JUN 15 1990

...HALF-INCH HAIL HAS BEEN REPORTED AT CHUGWATER...

AT 225 PM MDT SCATTERED THUNDERSTORMS CONTINUED OVER SOUTHEAST PLATTE...
SOUTH GOSHEN...AND EAST LARMIE COUNTIES OF SOUTHEAST WYOMING.
AT 200 PM MDT THE HIGHWAY DEPARTMENT IN CHUGWATER REPORTED HALF-INCH
HAIL AND MODERATE RAIN AS THE THUNDERSTORM PASSED DIRECTLY OVER THEM.
CHUGWATER IS 40 MILES NORTH OF CHEYENNE.

ANOTHER CELL JUST EAST OF CHEYENNE...NEAR HILLSDALE WILL LIKELY
PRODUCE PEA TO MARBLE SIZED HAIL...LOCALLY HEAVY RAIN AND GUSTY
WINDS AROUND 40 MILES AND HOUR.

THE THUNDERSTORMS WERE MOVING NORTHEAST AT 15 MILES AN HOUR.

A TORNADO WATCH REMAINS IN EFFECT FOR THE SOUTHEAST BORDER AREA OF
WYOMING UNTIL 900 PM MDT. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES. PEOPLE ARE URGED TO KEEP A CLOSE EYE ON THE
SKY AND BE PREPARED TO SEEK SHELTER IF THREATENING WEATHER APPROACHES.
CAS
Special weather statement, Jun 15, 2:49 PM MDT, 1 hour 53 minutes before
WYZ012-017-152120-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
250 PM MDT FRI JUN 15 1990

...A LINE OF THUNDERSTORMS IS JUST EAST OF CHUGWATER...

AT 245 PM MDT A LINE OF STORNG THUNDERSTORMS RAN FROM ABOUT 20 MILES
NORTH OF CHEYENNE IN LARAMIE COUNTY TO ABOUT 25 MILES SOUTHEAST OF
WHEATLAND IN SOUTH GOSHEN COUNTY. NO REPORTS OF SEVERE WEATHER HAVE
BEEN RECEIVED. HOWEVER...BASED ON PREVIOUS REPORTS AND RADAR...HAIL
OF ONE HALF INCH OR LARGER...LOCALLY HEAVY RAIN...AND WIND GUSTS
TO AROUND 45 MILES AN HOUR ARE POSSIBLE.

THE TOWNS OF VETERAN AND YODER ARE IN THE PATH OF THIS THUNDERSTORM.
THESE TWO TOWNS ARE ABOUT 20 MILES SOUTHWEST OF TORRINGTON IN SOUTH
GOSHEN COUNTY.

THE LINE OF THUNDERSTORMS WAS MOVING VERY SLOWLY EAST AT AROUND
5 MILES AN HOUR. THIS MAY PRODCUE LOCALIZED FLOODING OF SECONDARY
ROADS AND SMALL DRAINAGES.

A TORNADO WATCH REMAINS IN EFFECT FOR SOUTHEAST WYOMING UNTIL 900 PM
MDT.
CAS


The office that day

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

IssuedProductOfficeCountiesLasted
Jun 15, 4:06 PM MDTTornado WarningCYSLaramie54 min

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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.