Alert archive / Wyoming / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 30, NWS Cheyenne, WY

June 12, 1997Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 12, 1997, 1:35 PM MDT for Laramie County, Wyoming. It was in force for 45 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 12, 1997, 1:35 PM MDT (19:35 UTC)
Expired
Jun 12, 1997, 2:20 PM MDT
In force
45 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Laramie County, WY

What was reported inside it

TimeReportWhereRemark
Jun 12, 1:40 PM MDTHail 2.5Cheyenne, WY
Jun 12, 1:45 PM MDTHail 1Cheyenne, WYHail piled to a 4 inch depth.

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.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 7.6 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 1997-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 48 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 1997-06-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -3 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
48 J/kg
Mixed-layer CIN
-253 J/kg
Mixed-layer LCL
1774 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
-3 m²/s²
0-3 km storm-relative helicity
52 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 121934 RRA
SVRCYS
WYC021-122020-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
135 PM MDT THU JUN 12 1997

* SEVERE THUNDERSTORM WARNING FOR
  SOUTHWESTERN AND SOUTH CENTRAL LARAMIE COUNTY IN SOUTHEASTERN
WYOMING

* UNTIL 220 PM MDT

* SOME LOCATIONS AFFECTED
  CHEYENNE                         BY 145 PM MDT

* AT 130 PM MDT...A SEVERE THUNDERSTORM WAS INDICATED BY DOPPLER
  RADAR AND SPOTTER REPORTS 16 MILES WEST OF CHEYENNE OR 6 MILES
  SOUTHWEST OF SILVER CROWN MOVING NORTHEAST AT 15 MPH.
 
AT 125 A SPOTTER REPORTED HAIL ONE INCH IN DIAMETER AT MILE MARKER
348 ON INTERSTATE 80 12 MILES WEST OF CHEYENNE.

THIS IS A DANGEROUS STORM.  TAKE COVER NOW AND REMAIN AWAY FROM
WINDOWS.
 
WCJIN-WYSE

ROBINSON

&

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 12, 10:10 AM MDT, 3 hours 25 minutes before
WYZ059>070-NEZ001>003-019>021-054-055-130000-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHEYENNE WY
1010 AM MDT THU JUN 12 1997

THE SEVERE WEATHER POTENTIAL IN THE CHEYENNE NWS COUNTY WARNING AREA IS
MEDIUM OVER SOUTHEAST WYOMING AND THE SOUTHERN PANHANDLE TODAY...LOW IN
THE NORTHERN NEBRASKA PANHANDLE.

SPOTTER ACTIVATION MAY BE REQUIRED LATE THIS AFTERNOON IN SOUTHEAST
WYOMING AND THE SOUTHERN NEBRASKA PANHANDLE.

DISCUSSION...LOW LEVEL MOISTURE HAS RETURNED TO MOST OF THE AREA.
DAYTIME HEATING WILL CAUSE THE AIR MASS TO BECOME UNSTABLE DURING THE
AFTERNOON AND EVENING IN SOUTHEAST WYOMING AND THE SOUTHERN PANHANDLE
...AND SCATTERED THUNDERSTORMS WILL DEVELOP.  A FEW OF THESE MAY BECOME
STRONG ESPECIALLY DURING THE LATE AFTERNOON AND EVENING HOURS.

IN THE NORTHERN PANHANDLE...LOW CLOUDS WILL LIMIT SOLAR HEATING AND
THUNDERSTORM DEVELOPMENT THIS AFTERNOON.
<
WCJIN-WYSE-WYNE

JLH
Special weather statement, Jun 12, 10:12 AM MDT, 3 hours 23 minutes before
WYZ059>070-NEZ001>003-019>021-054-055-130000-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHEYENNE WY
1010 AM MDT THU JUN 12 1997

THE SEVERE WEATHER POTENTIAL IN THE CHEYENNE NWS COUNTY WARNING AREA IS
MEDIUM OVER SOUTHEAST WYOMING AND THE SOUTHERN PANHANDLE TODAY...LOW IN
THE NORTHERN NEBRASKA PANHANDLE.

SPOTTER ACTIVATION MAY BE REQUIRED LATE THIS AFTERNOON IN SOUTHEAST
WYOMING AND THE SOUTHERN NEBRASKA PANHANDLE.

DISCUSSION...LOW LEVEL MOISTURE HAS RETURNED TO MOST OF THE AREA.
DAYTIME HEATING WILL CAUSE THE AIR MASS TO BECOME UNSTABLE DURING THE
AFTERNOON AND EVENING IN SOUTHEAST WYOMING AND THE SOUTHERN PANHANDLE
...AND SCATTERED THUNDERSTORMS WILL DEVELOP.  A FEW OF THESE MAY BECOME
STRONG ESPECIALLY DURING THE LATE AFTERNOON AND EVENING HOURS.

IN THE NORTHERN PANHANDLE...LOW CLOUDS WILL LIMIT SOLAR HEATING AND
THUNDERSTORM DEVELOPMENT THIS AFTERNOON.
<
WCJIN-WYSE-WYNE

JLH

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 12, 2:19 PM MDTSevere Thunderstorm WarningCYSLaramie46 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 1997Every severe thunderstorm warning in 1997

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.