Alert archive / Wyoming / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 67, NWS Cheyenne, WY

July 4, 1990Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jul 4, 1990, 4:35 PM MDT for Laramie County, Wyoming. It was in force for 60 min.

The area

The counties it named.

The facts

Issued
Jul 4, 1990, 4:35 PM MDT (22:35 UTC)
Expired
Jul 4, 1990, 5:35 PM MDT
In force
60 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.

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 10.6 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 1990-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 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, Denver, CO at 12:00Z on 1990-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 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
3 J/kg
Mixed-layer CIN
-167 J/kg
Mixed-layer LCL
1212 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
85 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 042235
SVRCYS
WYC021-042335-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
435 PM MDT WED JUL 4 1990
 
THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 535 PM MDT
FOR PEOPLE IN THE FOLLOWING COUNTY...
 
IN SOUTHEAST WYOMING
          ...LARAMIE
 
THIS WARNING INCLUDES THE CITY OF CHEYENNE.
 
AT 427 PM MDT RADAR INIDICATED A LINE OF SEVERE THUNDERSTORMS OVER
WESTERN LARAMIE COUNTY OF SOUTHEAST WYOMING. THE LINE OF SEVERE
STORMS EXTENDED FROM 20 MILES NORTHWEST OF CHEYENNE TO 25 MILES
WEST OF CHEYENNE. THE LINE OF SEVERE STORMS WAS MOVING TO THE
EAST AT 20 MILES AN HOUR.
 
THE STORMS HAVE ALSO HAD A HISTORY OF VERY HEAVY RAINFALL AND SO
FLOODING OF SMALL STREAMS...LOW LYING AREAS AND URBAN AREAS IN
LARAMIE COUNTY IS POSSIBLE.
 
IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER FROM THE WEATHER IN A
STRONG BUILDING.  DAMAGING WIND...LARGE HAIL...VERY HEAVY RAIN...
AND DEADLY LIGHTNING ARE ALL POSSIBLE IN SEVERE THUNDERSTORMS.
STAY INSIDE AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.
WEILAND

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, Jul 4, 3:46 PM MDT, 49 minutes before
WYZ012-016-017-042245-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
345 PM MDT WED JUL 4 1990

...THUNDERSTORMS WERE INTENSIFYING OVER SOUTHEAST WYOMING...

AT 330 PM MDT THUNDERSTORMS WERE INTENSIFYING OVER THE SOUTHEAST
QUARTER OF WYOMING. THE STRONGER STORMS WERE 25 TO 30 MILES WEST OF
CHEYENNE. ALSO...OTHER THUNDERSTORMS WERE OVER THE SOUTHEAST...ALL
MOVING TO THE EAST AT 25 MILES AN HOUR.

AT 325 PM MDT MARBLE SIZED DIAMETER HAIL WAS REPORTED NEAR CRYSTAL
RESERVOIR...ABOUT 30 MILES WEST OF CHEYENNE. IN ADDITION...AT 340 PM
MDT CURT GOWDY STATE PARK...25 MILES WEST OF CHEYENNE...RECEIVED ONE
QUARTER INCH DIAMETER HAIL AS WELL AS AN INCH OF RAIN IN FIFTEEN
MINUTES.

AS THE STORMS MOVE EAST THROUGH THE EVENING...HAIL...VERY HEAVY RAIN...
GUSTY WINDS AND DANGEROUS LIGHTNING WILL OCCUR. THE STORMS WILL
CONTINUE TO BECOME STRONGER AS THEY MOVE EAST...AWAY FROM THE LARAMIE
RANGE.

PEOPLE OUTDOORS IN SOUTHEASbT WYOMING THROUGH THE EVENING SHOULD BE
PREPARED TO APPROPRIATE SHELTER WHEN A STORM APPROACHES.
WEILAND
Special weather statement, Jul 4, 4:16 PM MDT, 19 minutes before
NEZ001-005-011-042330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SCOTTSBLUFF NE
415 PM MDT WED JUL 4 1990

...THUNDERSTORMS ENTERING THE WESTERN NEBRASKA PANHANDLE...

AT 415 PM MDT...THUNDERSTORMS WERE ENTERING THE WESTERN NEBRASKA
PANHANDLE FROM EASTERN WYOMING.  THE STORMS EXTENDED FROM 15 MILES
SOUTHWEST OF HARRISON NEBRASKA...OR 55 MILES WEST OF CHADRON IN THE
NORTHERN NEBRASKA PANHANDLE TO 25 MILES SOUTHWEST OF SCOTTSBLUFF
NEBRASKA IN THE CENTRAL PANHANDLE.  THE STRONGEST STORM WAS 20 MILES
WEST OF SCOTTSBLUFF AND ALL OF THE STORMS WERE MOVING TO THE EAST AT
15 MILES AN HOUR.

BRIEF HEAVY RAIN...STRONG WIND AND SMALL HAIL IS POSSIBLE WITH THESE
STORMS AS THEY MOVE INTO EAST ACROSS SIOUX...SCOTTSBLUFF AND BANNER
COUNTIES OF THE NEBRASKA PANHANDLE UNTIL 530 PM MDT.
KIRK

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 4, 5:34 PM MDTSevere Thunderstorm WarningCYSLaramie56 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; the sounding from the Mesonet's radiosonde archive.