Alert archive / Wyoming / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 90, NWS Cheyenne, WY

August 2, 1997Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Aug 2, 1997, 7:57 PM MDT for Laramie County, Wyoming. It was in force for 33 min. 1 report 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
Aug 2, 1997, 7:57 PM MDT (01:57 UTC)
Expired
Aug 2, 1997, 8:30 PM MDT
In force
33 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Laramie County, WY

The radar

The Cheyenne radar (KCYS), 20 km from the middle of the area, began a volume at 01:57 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Aug 2, 8:05 PM MDTHail 0.75Pine Bluffs, 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.

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 2.0 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 00:00Z on 1997-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 425 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 00:00Z on 1997-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
425 J/kg
Mixed-layer CIN
-36 J/kg
Mixed-layer LCL
1911 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
27 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

590 
WUUS1 KCYS 030155 
SVRCYS

WYC021-030230-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING...CORRECTION TO DATE AND TIME
NATIONAL WEATHER SERVICE CHEYENNE WY
757 PM MDT SAT AUG 02 1997

* SEVERE THUNDERSTORM WARNING FOR
  SOUTHEAST LARAMIE COUNTY IN SOUTHEAST WYOMING

* UNTIL 830 PM MDT

* SOME LOCATIONS AFFECTED
  THIS STORM WILL REMAIN IN RURAL AREAS

* AT 750 PM DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 10 MILES
  SOUTHWEST OF PINE BLUFFS MOVING SOUTHEAST AT 15 MPH.  

LARGE HAIL IS LIKELY WITH THIS STORM.  SEEK SHELTER INSIDE A 
STURDY BUILDING AWAY FROM ALL WINDOWS UNTIL THE STORM PASSES.

WCJIN-WYSE
DMM

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, Aug 2, 2:40 PM MDT, 5 hours 17 minutes before
WYZ059-060-067-068-022145-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
240 PM MDT SAT AUG 2 1997

...HEAVY RAINS OVER PARTS OF EAST CENTRAL AND SOUTHEAST WYOMING...

AT 237 PM MDT...THUNDERSTORMS WITH HEAVY RAINFALL HAD DEVELOPED OVER
CONVERESE AND NORTHERN PLATTE COUNTIES.  THESE STORMS WERE GENERALLY
LOCATED FROM 15 MILES NORTH OF WHEATLAND TO NEAR DOUGLAS AND GLENROCK.

THE STORMS WERE MOVING EAST AT 15 TO 20 MPH AND WILL IMPACT THE TOWNS
OF DOUGLAS AND DEER CREEK THROUGH 3:30 PM.  THESE STORMS WILL THEN MOVE
INTO THE VICINITY OF KEELINE AND LUSK AND INTO NORTHERN SECTIONS OF
GOSHEN COUNTY TOWARD 3:00 PM OR 3:30 PM.

PEOPLE IN THESE AREAS SHOULD BE PREPARED FOR BRIEF HEAVY
RAINFALL...POSSIBLE UP TO A HALF AN INCH IN LESS THAN 30 MINUTES...AND
WIND GUSTS TO 35 MPH.   THERE MAY ALSO BE SOME VERY SMALL HAIL WITH THE
STRONGEST STORMS.

WCJIN-WYSE

DMM
Special weather statement, Aug 2, 2:41 PM MDT, 5 hours 16 minutes before
WYZ059-060-067-068-022145-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
240 PM MDT SAT AUG 2 1997

...HEAVY RAINS OVER PARTS OF EAST CENTRAL AND SOUTHEAST WYOMING...

AT 237 PM MDT...THUNDERSTORMS WITH HEAVY RAINFALL HAD DEVELOPED OVER
CONVERESE AND NORTHERN PLATTE COUNTIES.  THESE STORMS WERE GENERALLY
LOCATED FROM 15 MILES NORTH OF WHEATLAND TO NEAR DOUGLAS AND GLENROCK.

THE STORMS WERE MOVING EAST AT 15 TO 20 MPH AND WILL IMPACT THE TOWNS
OF DOUGLAS AND DEER CREEK THROUGH 3:30 PM.  THESE STORMS WILL THEN MOVE
INTO THE VICINITY OF KEELINE AND LUSK AND INTO NORTHERN SECTIONS OF
GOSHEN COUNTY TOWARD 3:00 PM OR 3:30 PM.

PEOPLE IN THESE AREAS SHOULD BE PREPARED FOR BRIEF HEAVY
RAINFALL...POSSIBLE UP TO A HALF AN INCH IN LESS THAN 30 MINUTES...AND
WIND GUSTS TO 35 MPH.   THERE MAY ALSO BE SOME VERY SMALL HAIL WITH THE
STRONGEST STORMS.

WCJIN-WYSE

DMM

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 3, 2:38 PM MDTSevere Thunderstorm WarningCYSAlbany42 min
Aug 3, 3:24 PM MDTSevere Thunderstorm WarningCYSAlbany41 min
Aug 3, 3:32 PM MDTSevere Thunderstorm WarningCYSAlbany43 min
Aug 3, 4:00 PM MDTTornado WarningCYSLaramie45 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; radar from the NEXRAD Level II archive.