Alert archive / Wyoming / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 37, NWS Cheyenne, WY

June 9, 1990Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 9, 1990, 5:56 PM MDT for Laramie County, Wyoming. It was in force for 64 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 9, 1990, 5:56 PM MDT (23:56 UTC)
Expired
Jun 9, 1990, 7:00 PM MDT
In force
64 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 9, 6:12 PM MDTHail 1.75Laramie, WY
Jun 9, 6:40 PM MDTHail 1.25Laramie, 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, 11.9 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 1990-06-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 31 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 1990-06-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 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
31 J/kg
Mixed-layer CIN
-456 J/kg
Mixed-layer LCL
2000 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
25 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 092356
SVRCYS
WYC021-100100-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING 
NATIONAL WEATHER SERVICE CHEYENNE WY
556 PM MDT SAT JUN 9 1990

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 700 PM MDT FOR PEOPLE IN THE FOLLOWING 
COUNTY

   IN THE SOUTHEAST PART OF WYOMING
      SOUTHERN LARAMIE COUNTY

THIS INCLUDES THE CITY OF CHEYENNE PLUS THE TOWNS OF CARPENTER AND
BURNS.

AT 550 PM MDT RADAR INDICATED A SEVERE THUNDERSTORM ABOUT 15 MILES
SOUTH OF CHEYENNE. THE STORM WAS MOVING NORTH AT 10 MILES AN
HOUR.

LARGE HAIL HAS ALREADY BEEN REPORTED WITH THIS STORM.

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS IN EXCESS OF 60 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 DO NOT DRIVE INTO
AREAS WHERE WATER COVERS THE ROAD.

A TORNADO WIATCH IS ALSO IN EFFECT FOR THE WARNED AREA.  REMEMBER...
SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES
WITH LITTLE OR NO ADVANCE WARNING.

MENTZER

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 9, 2:10 PM MDT, 3 hours 46 minutes before
WYZ015>017-092130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
210 PM MDT SAT JUN 9 1990

...THE THREAT OF SEVERE WEATHER WILL INCREASE THIS AFTERNOON AND
EVENING...

A TORNADO WATCH HAS BEEN ISSUED FOR NORTHEAST COLORADO BUT DOES NOT
...AT THIS TIME...INCLUDE ANY AREA OF WYOMING.  HOWEVER...SEVERE
THUNDERSTORMS ARE POSSIBLE IN THE SOUTHEAST CORNER OF WYOMING LATE
THIS AFTERNOON AND EVENING.

THUNDERSTORMS ARE DEVLOPING ALONG THE LARAMIE RANGE ABOUT 20 MILES
WEST OF CHEYENNE THIS AFTERNOON AND WILL MOVE SLOWLY EAST.  AROUND
5PM TO 6PM THUNDERSTORMS HAIL AND GUSTY WINDS WILL BE POSSIBLE ALONG
I-25 BETWEEN CHEYENNE AND CHUGWATER.  CHUGWATER IS ABOUT 22 MILES
SOUTH O-F WHEATLAND.

THUNDERSTORMS...SOME POSSIBLY SEVERE...WILL CONTINUE TIL AROUND SUNSET.
PEOPLE IN SOUTHEAST WYOMING ARE URGED TO KEEP AN EYE ON THE SKY AND
KEEP UP TO DATE BY LISTENING TO THIS STATION FOR WEATHER DETAILS.

SANDERS
Special weather statement, Jun 9, 4:40 PM MDT, 1 hour 16 minutes before
WYZ013-014-092330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
440 PM MDT SAT JUN 9 1990

...THUNDERSTORMS MOVE OVER SOUTHWEST WYOMING...

WIDELY SCATTERED THUNDERSTORMS MOVED OVER SOUTHWEST WYOMING THIS
AFTERNOON. AT 430 PM MDT RADAR INDICATED THUNDERSTORMS EXTENDING FROM
BIG PINEY TO ROCK SPRINGS. THE STRONGEST CELL WAS NEAR THE TOWN OF
LYMAN...ABOUT 35 MILES EAST OF EVANSTON.  STORMS WERE MOVING
NORTHEAST AT 15 MILES AN HOUR.

THUNDERSTORMS WILL CONTINUE THROUGH THE NIGHT OVER WESTERN WYOMING.
SOME STORMS MAY PRODUCE GUSTY WINDS...BRIEF HEAVY RAIN...AND FREQUENT
LIGHTNING. STAY INDOORS IF A THUNDERSTORM APPROACHES YOUR AREA.

MENTZER
Special weather statement, Jun 9, 5:32 PM MDT, 24 minutes before
WYZ017-100030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
535 PM MDT SAT JUN 9 1990

...THUNDERSTORMS WERE BUILDING IN SOUTHEAST WYOMING...

WEATHER RADAR SHOWED THAT THUNDERSTORMS WERE CONTINUING TO BUILD IN
LARAMIE COUNTY OF FAR SOUTHEAST WYOMING AT 530 PM.  NONE OF THE STORMS
AT THIS TIME WERE VERY STRONG.  HOWEVER...CONDITIONS ARE RIPE FOR THESE
STORMS TO CONTINUE GETTING STRONGER IN SOUTHEAST WYOMING THIS EVENING.

JUST ACROSS THE BORDER IN NORTHEAST COLORADO...SOME STORMS WERE QUITE
STRONG.  A TORNADO WAS SPOTTED BY THE PUBLIC AT 515 PM 5 MILES WEST
OF THE TOWN OF NUNN COLORADO...WHICH IS ABOUT 30 MILES SOUTH OF THE
CITY OF CHEYENNE.

RESIDENTS OF SOUTHEAST WYOM9ING SHOULD KEEP AN EYE TO THE SKY THIS
EVENING AS THESE STORMS CONTINUE TO DEVELOP.  IF THREATENING WEATHER
APPROACHES...GO TO A SAFE PLACE.

DASELER

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.