Alert archive / Wyoming / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 9, NWS Cheyenne, WY

May 20, 1990Goshen County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at May 20, 1990, 2:27 PM MDT for Goshen County, Wyoming. It was in force for 63 min.

The area

The counties it named.

The facts

Issued
May 20, 1990, 2:27 PM MDT (20:27 UTC)
Expired
May 20, 1990, 3:30 PM MDT
In force
63 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Goshen 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, 8.5 hours before the alert went out and 251 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 1990-05-20Temperature 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 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 1990-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 111 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
597 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
103 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 202030
SVRCYS
WYC015-202130-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
227 PM MDT SUN MAY 20 1990
 
THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  330 PM MDT
FOR PEOPLE IN THE FOLLOWING COUNTY...
 
IN SOUTHEAST WYOMING
          ...GOSHEN AND THE EASTERN HALF OF LARAMIE COUNTY...
CITIES INCLUDED ARE PINE BLUFFS...ALBIN...BURNS AND HILLSDALE.
 
RADAR AND SURFACE REPORTS INDICATE A 15-MILE WIDE LINE OF
THUNDERSTORMS FROM NEAR GUERNSEY SOUTHWARD TO NEAR HILLSDALE.
THE LINE OF STORMS IS MOVING EAST AT 20 MILES AN HOUR. SEVERAL
FUNNEL CLOUDS HAVE BEEN SIGHTED WITH THESE STORMS...BUT NONE HAVE
TOUCHED DOWN.
 
 
 
 
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 BUI@LDING BUT STAY AWAY FROM WINDOWS.
EKB

The office that day

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

IssuedProductOfficeCountiesLasted
May 20, 1:30 PM MDTSevere Thunderstorm WarningCYSLaramie60 min
May 20, 1:53 PM MDTTornado WarningCYSLaramie37 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.