Alert archive / Wyoming / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 5, NWS Cheyenne, WY

May 17, 1987Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at May 17, 1987, 4:00 PM MDT for Laramie County, Wyoming. It was in force for 45 min.

The area

The counties it named.

The facts

Issued
May 17, 1987, 4:00 PM MDT (22:00 UTC)
Expired
May 17, 1987, 4:45 PM MDT
In force
45 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Laramie County, WY

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 10.0 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 1987-05-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 160 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 1987-05-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -34 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
160 J/kg
Mixed-layer CIN
-127 J/kg
Mixed-layer LCL
1490 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-34 m²/s²
0-3 km storm-relative helicity
-2 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 17, 10:48 AM MDT, 5 hours 12 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
1045 AM MDT SUN MAY 17 1987

THUNDERSTORMS HAVE DEVELOPED SINCE 1030 AM MDT OVER THE SNOWY RANGE
AND THE LARAMIE MOUNTAINS...IN SOUTHEAST AND SOUTH CENTRAL WYOMING.
AT 1035 AM MDT HEAVY RAIN AND PEA SIZE HAIL WERE REPORTED 25 MILES
WEST OF CHEYENNE.

OTHER SHOWERS AND THUNDERSTORMS WERE WIDELY SCATTERED OVER THAT
PORTION OF WYOMING. THE HEAVIEST THUNDERSTORM WAS LOCATED ABOUT O25
MILES WEST OF CHEYENNE..ALONG THE EAST SLOPES OF THE LARAMIE RANGE.

MORE SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON...WITH
THE POSSIBLITY OF BRIEF HEAVY RAIN AND SMALL HAIL.
WEILAND
Special weather statement, May 17, 12:09 PM MDT, 3 hours 51 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
1205 PM MDT SUN MAY 17 1987

SCATTERED THUNDERSTORMS CONTINUE TO DEVELOP OVER SOUTH CENTRAL AND
SOUTHEAST WYOMING...WITH THE STORMS PRODUCING HEAVY RAIN OVER THE
LARAMIE AND SNOWY MOUNTAIN RANGES.

HEAVY RAIN...PEA SIZE HAIL AND FREQUENT LIGHTNING WAS REPORTED WITH
THE THUNDERSTORMS OVER THE LARAMIE RANGE...BETWEEN LARAMIE AND
CHEYENNE. INTENSE THUNDERSTORMS PRODUCING HEAVY RAIN WERE LOCATED
ABOUT 8 MILES WEST OF CHEYENNE AND 10 MILES NORTHWEST OF CHEYENNE.
THE THUNDERSTORMS WERE MOVING TO THE NORTHEAST AT 10 TO 15 MPH.

THUNDERSTORMS WILL CONTINUE TO DEVELOP OVER SOUTH CENTRAL AND SOUTHEAST
WYOMING THIS AFTERNOON...WITH BRIEF HEAVY RAIN...SMALL HAIL AND
DANGEROUS LIGHTNING LIKELY. PEOPLE IN THAT PART OF THE STATE SHOULD BE
AWARE OF THE POSSIBILITY OF THUNDERSTORMS...AND IF HEAVY RAIN IS
EXPERIENCED...MOVE TO HIGHER GROUND.
WEILAND

The office that day

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

IssuedProductOfficeCountiesLasted
May 17, 12:54 PM MDTSevere Thunderstorm WarningCYSLaramie66 min
May 17, 1:53 PM MDTSevere Thunderstorm WarningCYSLaramie67 min
May 17, 2:58 PM MDTSevere Thunderstorm WarningCYSLaramie62 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 1987Every severe thunderstorm warning in 1987

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.