Alert archive / Wyoming / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 86, NWS Cheyenne, WY

August 1, 1990Sweetwater County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Aug 1, 1990, 3:25 PM MDT for Sweetwater County, Wyoming. It was in force for 65 min.

The area

The counties it named.

The facts

Issued
Aug 1, 1990, 3:25 PM MDT (21:25 UTC)
Expired
Aug 1, 1990, 4:30 PM MDT
In force
65 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Sweetwater 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

Lander/Hunt Fiel, WY (KLND), launched 12:00Z, 9.4 hours before the alert went out and 130 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, Lander/Hunt Fiel, WY at 12:00Z on 1990-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Lander/Hunt Fiel, WY at 12:00Z on 1990-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2232 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
45 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 012125
SVRCYS
WYC037-012230-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING 
NATIONAL WEATHER SERVICE CHEYENNE WY
325 PM MDT WED AUG 1 1990

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 430 PM MDT FOR PEOPLE IN THE FOLLOWING 
COUNTY

   IN THE SOUTH CENTRAL PART OF WYOMING
      WESTERN AND NORTHERN SWEETWATER COUNTY

AT 320 PM MDT...A SEVERE THUNDERSTORM WAS JUST EAST OF ROCK SPRINGS
MOVING NORTHEAST AT 15 MILES AN HOUR.  THIS STORM PRODUCED A WIND
GUST TO 63 MILES AN HOUR AT THE ROCK SPRINGS AIRPORT EAST OF
ROCK SPRINGS AROUND 310 PM MDT.

THIS IS A DANGEROUS STORM.  IF YOU ARE IN ITS PATH YOU SHOULD
PREPARE FOR DAMAGING WIND IN EXC%ESS OF 60 MPH...LARGE HAIL...AND
DEADLY LIGHTNING.  BOATERS SHOULD MOVE OFF LAKES TO NEARBY SHELTER.
PEOPLE OUTDOORS SHOULD MOVE INSIDE STRONG BUILDINGS.  STAY AWAY
FROM WINDOWS.

HATTEN

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 5:35 PM MDTSevere Thunderstorm WarningCYSCarbon40 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.