Alert archive / Wyoming / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 15, NWS Cheyenne, WY

May 7, 1998Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at May 7, 1998, 11:47 AM MDT for Laramie County, Wyoming. It was in force for 18 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 7, 1998, 11:47 AM MDT (17:47 UTC)
Expired
May 7, 1998, 12:05 PM MDT
In force
18 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 17:44 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.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 5.8 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 1998-05-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 23 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 1998-05-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 107 square meters per square second.19395878Sfc1 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
23 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
1042 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
107 m²/s²
0-3 km storm-relative helicity
87 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.

244 
WUUS1 KCYS 071748 RRA
SVRCYS
WYC021-071810-

BULLETIN - IMMEDIATE BROADCAST REQUESTED...CORRECTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
1147 AM MDT THU MAY 7 1998

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

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

* UNTIL 1205 PM MDT

* AT 1131 AM MDT...CONSIDERABLE SMALL HAIL AND SOME DIME SIZED HAIL
  WAS REPORTED BY MILITARY PERSONNEL NEAR HORSE CREEK.  ANOTHER SEVERE
  STORM WAS 20 MILES NORTHEAST OF CHEYENNE.  THE SEVERE STORMS WERE
  MOVING SOUTHEAST AT 25 MPH.

* THE SEVERE THUNDERSTORMS WILL REMAIN OVER RURAL AREAS.

GO INSIDE A STURDY BUILDING AND STAY AWAY FROM WINDOWS

&
CORRECTED TO TAKE OUT THE MENTION OF THE TORNADO WATCH.

WCJIN-WYSE
WEILAND

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, May 7, 10:01 AM MDT, 1 hour 46 minutes before
WYZ059>070-NEZ001>003-019>021-054-055-080000-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHEYENNE WY
1001 AM MDT THU MAY 7 1998

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

SPOTTER ACTIVATION WILL NOT BE REQUIRED.

DISCUSSION...SHOWERS AND THUNDERSTORMS WILL AGAIN BE FAIRLY WIDESPREAD
OVER SOUTHEAST WYOMING AND THE WESTERN NEBRASKA PANHANDLE THIS
AFTERNOON.  THIS WILL ESPECIALLY BE THE CASE IN THE SOUTHERN NEBRASKA
PANHANDLE AND FROM GOSHEN AND PLATTE COUNTIES SOUTH AND WESTWARD.  THE
ATMOSPHERE WILL BE MOIST AND FAIRLY UNSTABLE...BUT THE COOL
TEMPERATURES AT THE SURFACE WILL LIMIT STORM INTENSITY.  AS WAS THE
CASE ON WEDNESDAY...SOME OF THE STORMS WILL PRODUCE HEAVY RAIN AND
SMALL HAIL AS THEY MOVE TO THE SOUTHEAST AT 20 MPH.  THE CURRENT
SHOWERS IN THE WESTERN NEBRASKA PANHANDLE WILL SLOWLY INTENSIFY IN THE
SOUTHERN PANHANDLE DURING THE AFTERNOON.

WCJIN-WYSE-WYNE
WEILAND
Special weather statement, May 7, 10:01 AM MDT, 1 hour 46 minutes before
WYZ059>070-NEZ001>003-019>021-054-055-080000-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHEYENNE WY
1001 AM MDT THU MAY 7 1998

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

SPOTTER ACTIVATION WILL NOT BE REQUIRED.

DISCUSSION...SHOWERS AND THUNDERSTORMS WILL AGAIN BE FAIRLY WIDESPREAD
OVER SOUTHEAST WYOMING AND THE WESTERN NEBRASKA PANHANDLE THIS
AFTERNOON.  THIS WILL ESPECIALLY BE THE CASE IN THE SOUTHERN NEBRASKA
PANHANDLE AND FROM GOSHEN AND PLATTE COUNTIES SOUTH AND WESTWARD.  THE
ATMOSPHERE WILL BE MOIST AND FAIRLY UNSTABLE...BUT THE COOL
TEMPERATURES AT THE SURFACE WILL LIMIT STORM INTENSITY.  AS WAS THE
CASE ON WEDNESDAY...SOME OF THE STORMS WILL PRODUCE HEAVY RAIN AND
SMALL HAIL AS THEY MOVE TO THE SOUTHEAST AT 20 MPH.  THE CURRENT
SHOWERS IN THE WESTERN NEBRASKA PANHANDLE WILL SLOWLY INTENSIFY IN THE
SOUTHERN PANHANDLE DURING THE AFTERNOON.

WCJIN-WYSE-WYNE
WEILAND
Special weather statement, May 7, 10:07 AM MDT, 1 hour 40 minutes before
WYZ059>070-NEZ001>003-019>021-054-055-090000-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHEYENNE WY
1007 AM MDT THU MAY 7 1998

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

SPOTTER ACTIVATION WILL NOT BE REQUIRED.

DISCUSSION...SHOWERS AND THUNDERSTORMS WILL AGAIN BE FAIRLY WIDESPREAD
OVER SOUTHEAST WYOMING AND THE SOUTHERN NEBRASKA PANHANDLE THIS
AFTERNOON.  THE AIRMASS REMAINS FAIRLY MOIST AND UNSTABLE AND SO SMALL
HAIL AND BRIEF HEAVY RAIN WILL ACCOMPANY MANY OF THE STORMS.  THE HAIL
SIZE WILL BE LIMITED BY THE FAIRLY COOL TEMPERATURES.  HOWEVER...WITH
BETTER WIND SHEAR IN THE ATMOSPHERE THERE IS A BIT GREATER POSSIBILITY
DURING THE AFTERNOON OF LARGER HAIL THAN IN RECENT DAYS.

WCJIN-WYSE-WYNE
WEILAND

The office that day

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

IssuedProductOfficeCountiesLasted
May 7, 11:40 AM MDTSevere Thunderstorm WarningCYSLaramie25 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 1998Every severe thunderstorm warning in 1998

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; radar from the NEXRAD Level II archive.