Alert archive / Wyoming / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 30, NWS Cheyenne, WY

May 19, 1998Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at May 19, 1998, 2:59 PM MDT for Laramie County, Wyoming. It was in force for 46 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 19, 1998, 2:59 PM MDT (20:59 UTC)
Expired
May 19, 1998, 3:45 PM MDT
In force
46 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 21:01 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, 9.0 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 12:00Z on 1998-05-19Temperature 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 1998-05-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 26 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
3220 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
26 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.

423 
WUUS1 KCYS 192058 RRA
SVRCYS
WYC021-192145-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
259 PM MDT TUE MAY 19 1998

THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A

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

* UNTIL 345 PM MDT

* AT 255 PM...SPOTTERS INDICATED A SEVERE THUNDERSTORM 20 MILES NORTH
  OF CHEYENNE...JUST EAST OF I-25. MOVMENT WAS EAST AT 15 MPH.
  THIS STORM WAS PRODUCING GOLF BALL SIZED HAIL.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  IN OPEN COUNTRY

THIS IS A DANGEROUS STORM STAY INDOORS AWAY FROM WINDOWS.

&
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, May 19, 9:45 AM MDT, 5 hours 14 minutes before
WYZ059>070-NEZ001>003-019>021-054-055-200000-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHEYENNE WY
945 AM MDT TUE MAY 19 1998

THE SEVERE WEATHER POTENTIAL IN THE CHEYENNE NWS COUNTY WARNING AREA
IS MODERATE TODAY EAST OF THE LARAMIE MOUNTAIN RANGE AND LOW WEST OF IT.

SPOTTER ACTIVATION WILL LIKELY BE REQUIRED FROM CONVERSE...PLATTE AND
LARAMIE COUNTIES OF WYOMING EAST THROUGH THE WESTERN NEBRASKA PANHANDLE.

DISCUSSION...THE AIRMASS OVER SOUTHEAST WYOMING AND THE WESTERN
NEBRASKA PANHANDLE THIS AFTERNOON WILL BE AS WARM AS MONDAY AND ALOT
MORE MOIST.  THE ATMOSPHERE IS EXPECTED TO AT LEAST BECOME MODERATELY
UNSTABLE BY MID AFTERNOON EAST OF THE LARAMIE MOUNTAINS IN WYOMING
THROUGH THE WESTERN NEBRASKA PANHANDLE.  AN UPPER LEVEL DISTURBANCE...
FORECAST TO BE ALONG THE WYOMING/NEBRASKA BORDER LATE IN THE AFTERNOON
...WILL CONTRIBUTE TO THE STRENGTH OF THE THUNDERSTORMS.  THE STORMS
WILL BE ABLE TO PRODUCE BRIEF HEAVY RAIN...STRONG WINDS AND HAIL
POSSIBLY UP TO THREE QUARTER INCH DIAMETER.
<
WEST OF THE LARAMIE MOUNTAINS...IN CARBON AND ALBANY COUNTIES...THE
MAIN THREAT REMAINS STRONG WIND GUSTS WITH ANY THUNDERSTORMS.

WCJIN-WYNE-WYSE

COX
Special weather statement, May 19, 9:45 AM MDT, 5 hours 14 minutes before
WYZ059>070-NEZ001>003-019>021-054-055-200000-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHEYENNE WY
945 AM MDT TUE MAY 19 1998

THE SEVERE WEATHER POTENTIAL IN THE CHEYENNE NWS COUNTY WARNING AREA
IS MODERATE TODAY EAST OF THE LARAMIE MOUNTAIN RANGE AND LOW WEST OF IT.

SPOTTER ACTIVATION WILL LIKELY BE REQUIRED FROM CONVERSE...PLATTE AND
LARAMIE COUNTIES OF WYOMING EAST THROUGH THE WESTERN NEBRASKA PANHANDLE.

DISCUSSION...THE AIRMASS OVER SOUTHEAST WYOMING AND THE WESTERN
NEBRASKA PANHANDLE THIS AFTERNOON WILL BE AS WARM AS MONDAY AND ALOT
MORE MOIST.  THE ATMOSPHERE IS EXPECTED TO AT LEAST BECOME MODERATELY
UNSTABLE BY MID AFTERNOON EAST OF THE LARAMIE MOUNTAINS IN WYOMING
THROUGH THE WESTERN NEBRASKA PANHANDLE.  AN UPPER LEVEL DISTURBANCE...
FORECAST TO BE ALONG THE WYOMING/NEBRASKA BORDER LATE IN THE AFTERNOON
...WILL CONTRIBUTE TO THE STRENGTH OF THE THUNDERSTORMS.  THE STORMS
WILL BE ABLE TO PRODUCE BRIEF HEAVY RAIN...STRONG WINDS AND HAIL
POSSIBLY UP TO THREE QUARTER INCH DIAMETER.
<
WEST OF THE LARAMIE MOUNTAINS...IN CARBON AND ALBANY COUNTIES...THE
MAIN THREAT REMAINS STRONG WIND GUSTS WITH ANY THUNDERSTORMS.

WCJIN-WYNE-WYSE

COX

The office that day

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

IssuedProductOfficeCountiesLasted
May 19, 4:01 PM MDTSevere Thunderstorm WarningCYSNiobrara34 min
May 19, 4:57 PM MDTSevere Thunderstorm WarningCYSNiobrara33 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.