Alert archive / Wyoming / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 94, NWS Cheyenne, WY

August 12, 1997Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Aug 12, 1997, 3:05 PM MDT for Laramie County, Wyoming. It was in force for 45 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 12, 1997, 3:05 PM MDT (21:05 UTC)
Expired
Aug 12, 1997, 3:50 PM MDT
In force
45 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 21:06 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 12, 3:27 PM MDTThunderstorm Wind 72Cheyenne, WYReported at F.E. Warren Air Force Base.

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, 9.1 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 1997-08-12Temperature 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, Denver, CO at 12:00Z on 1997-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 square meters per square second.1939587897Sfc1 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
1399 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
0 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 122105 RRA
SVRCYS
WYC021-122150-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
305 PM MDT TUE AUG 12 1997

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

* UNTIL 350 PM MDT

* SOME AFFECTED LOCATIONS INCLUDE
  CHEYENNE

* AT 304 PM MDT...DOPPLER RADAR INDICATED A LINE THUNDERSTORMS MOVING
  EAST AT 30 MPH.  THIS STORM WILL PRODUCE WIND GUSTS OVER 55 MPH
  ALONG WITH HAIL UP TO 3/4 OF AN INCH.  
 
 
STRONG WINDS WITH THIS STORM MAY CAUSE INJURY OR DAMAGE.  TAKE SHELTER
INSIDE A STURDY BUILDING AWAY FROM ALL DOORS AND WINDOWS.

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 12, 10:08 AM MDT, 4 hours 57 minutes before
WYZ059>070-NEZ001>003-019>021-054-055-130000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
1008 AM MDT TUE AUG 12 1997

THE SEVERE WEATHER POTENTIAL IN THE CHEYENNE NWS COUNTY WARNING AREA
IS MODERATE TODAY.

SPOTTER ACTIVATION MIGHT BE NECESSARY.

DISCUSSION...CLEARING WITH GOOD SURFACE WARMING AND PLENTY OF LOW LEVEL
MOISTURE SHOULD BE CONDUCIVE FOR SOME THUNDERSTORM DEVELOPMENT THIS
AFTERNOON. A FEW THUNDERSTORMS COULD HAVE LOCALLY HEAVY RAINS.

WCJIN-WYSE-WYNE
WTP

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.