Alert archive / Wyoming / Flash Flood Warnings in 1991

Flash Flood Warning 9, NWS Cheyenne, WY

June 1, 1991Albany County, Laramie County, Wyoming

NWS Cheyenne, WY issued this flash flood warning at Jun 1, 1991, 7:50 PM MDT for Albany County, Laramie County, Wyoming. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued
Jun 1, 1991, 7:50 PM MDT (01:50 UTC)
Expired
Jun 2, 1991, 12:00 AM MDT
In force
4 hr
Issued by
NWS Cheyenne, WY
Area
Whole counties

Counties Albany County, WY, Laramie County, WY

The nearest sounding before it

Denver, CO (KDEN), launched 00:00Z, 1.8 hours before the alert went out and 245 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 1991-06-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 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 1991-06-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -342 square meters per square second.193958Sfc1 km3 km6 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
1289 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
-342 m²/s²
0-3 km storm-relative helicity
-213 m²/s²
Significant tornado parameter
0.0
Supercell composite
-4.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KCYS 020151
FFWCYS
WYC001-021-020600-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
750 PM MDT SAT JUN 1 1991
 
THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL MIDNIGHT THIS SATURDAY EVENING
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN SOUTHEAST WYOMING
 
   ...SOUTHERN ALBANY COUNTY...AND ALL OF LARAMIE COUNTY
 
AT 745 PM MDT...STRONG THUNDERSTORMS WITH VERY HEAVY RAIN CONTINUED
TO DEVELOP OVER EXTREME SOUTHEAST WYOMING.  WIDESPREAD STREET FLOODING
WAS OCCURRING IN BOTH LARAMIE AND CHEYENNE.  DUCK CREEK 20 MILES WEST
SOUTHWEST OF CHEYENNE WAS REPORTED OUT OF IT'S BANKS.
 
THESE STRONG THUNDERSTORMS WITH HEAVY RAIN WILL CONTINUE OVER EXTREME
SOUTHEAST WYOMING THROUGH MIDNIGHT.  THERFORE...THE NATIONAL WEATHER
SERVICE HAS ISSUED A FLASH FLOOD WARNING EFFECTIVE UNTIL MIDNIGHT FOR
ALL OF LARAMIE COUNTY AND SOUTHERN ALBANY COUNTY IN SOUTHEAST WYOMING.
 
A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT.  IT'S
IMPORTANT TO KNOW WHERE YOU ARE RELATIVE TO STREAMS...RIVERS...OR
CREEKS WHICH CAN BECOME KILLERS IN HEAVY RAINS.  CAMPERS SHOULD
AVOID CAMPING ALONG STREAMS OR CREEKS DURING THREATENING RAINS.
 
MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES.  DO NOT
ATTEMPT TO CROSS BRIDGES...DIPS...OR LOW SPOTS IF WATER COVERS
THE ROADWAY.  NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL
ONE...ON FOOT.  TO ESCAPE RISING WATER MOVE UP TO HIGHER GROUND.
 
VIRGILLITO

What forecasters said that day

The local office's own words before this flash flood 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, Jun 1, 3:50 PM MDT, 4 hours before
WYZ013-014-012245-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
349 PM MDT SAT JUN 1 1991

SCATTERED THUNDERSTORMS CONTINUED OVER SOUTHWEST WYOMING AT 340 PM.
A FEW OF THE STORMS WERE LIKELY PRODUCING HEAVY RAIN AND SMALL HAIL
...AS WELL AS DEADLY LIGHTNING.  SINCE THE THUNDERSTORMS WERE MOVING
NORTHWEST AT ONLY 15 MILES AN HOUR...SOME FLOODING OF LOW LYING AREAS
MAY ALSO OCCUR.

THUNDERSTORMS WILL CONTINUE OVER SOUTHWEST WTYOMING THROUGH THE EVENING
HOURS.  PEOPLE IN SOUTHWEST WYOMING SHOULD KEEP AN EYE ON THE SKY THIS
AFTERNOON AND EVENING.  SHOULD A THUNDERSTORM APPROACH YOUR AREA...
SEEK A SAFE PLACE IMMEDIATELY...INDOORS IF POSSIBLE.

HATTEN
Special weather statement, Jun 1, 5:23 PM MDT, 2 hours 27 minutes before
WYZ015-016-017-020000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
523 PM MDT SAT JUN 1 1991

...SOME STRONG THUNDERSTORMS WERE STARTING TO DEVELOP OVER SOUTHEAST
WYOMING AT 520 PM...

SCATTERED THUNDERSTORMS WERE DEVELOPING AT 520 PM OVER THE SOUTHERN
PARTS OF ALBANY AND LARAMIE COUNTIES.  THE STRONGEST STORM WAS LOCATED
NEAR BURNS...OR ABOUT 25 MILES EAST OF CHEYENNE.  OTHER STORMS WERE
BECOMING QUITE STRONG OVER THE EXTREME SOUTHERN END OF THE LARAMIE
MOUNTAIN RANGE...ABOUT 20 MILES SOUTHEAST OF LARAMIE.

THE STORMS WERE MOVING TO THE NORTHWEST AT ABOUT 25 MILES AN HOUR.

PEOPLE IN LARAMIE AND ALBANY COUNTIES SHOULD KEEP AN EYE ON THE SKY
THIS EVENING.  THESE STORMS WILL LIKELY PRODUCE HAIL...GUSTY WINDS...
AND LOCALLY HEAVY RAINS.  A FLASH FLOOD WATCH REMAINS IN EFFECT FOR
THE FOOTHILLS OF THE LARAMIE AND SNOWY RANGES OVERNIGHT.

JAD
Special weather statement, Jun 1, 5:34 PM MDT, 2 hours 16 minutes before
WYZ013-014-020015-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
533 PM MDT SAT JUN 1 1991

...THUNDERSTORMS WITH HEAVY RAIN WERE MOVING THROUGH SOUTHWEST
WYOMING AT 525 PM...

A BAND OF THUNDERSTORMS WAS LOCATED ACROSS SOUTHWEST WYOMING AT 525
PM.  THE BAND EXTENDED ACROSS MUCH OF CENTRAL AND SOUTHERN SWEETWATER
COUNTY...AND ON WEST INTO UINTA AND SOUTHERN LINCOLN COUNTIES.

THE MAIN WEATHER HAZARD WITH THESE STORMS HAS BEEN SOME HEAVY RAIN
AND DEADALY LIGHTNING.  PEA TO MARBLE SIZE HAIL WAS REPORTED AT 520 PM
AT COKEVILLE...WHICH IS 30 MILES NORTHWEST OF KEMMERER.

PEOPLE IN SOUTHWEST WYOMING SHOULD REMAIN ALERT TO THESE STORMS.  THEY
WILL CONTINUE TO PRODUCE SMALL HAIL AND HEAVY RAINS THROUGH THIS
EVENING.  SOME SMALL STREAMS MAY BRIEFLY OVERFLOW THEIR BANKS...AND
MOTORISTS SHOULD BE ON THE LOOKOUT FOR WATER ON ROADS.

JAD
Special weather statement, Jun 1, 5:47 PM MDT, 2 hours 3 minutes before
NEZ001-005-011-020030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SCOTTSBLUFF NE
545 PM MDT SAT JUN 1 1991

...STRONG THUNDERSTORM IN THE SOUTHWESR NEBRASKA PANHANDLE...

AT 540 PM MDT...RADAR INDICATED A STRONG THUNDERSTORM 5 MILES NORTHWEST
OF KIMBALL OR 35 MILES NORTHWEST OF SIDNEY NEBRASKA MOVING TO THE
NORTHWEST AT 25 MPH.  OTHER THUNDERSHOWERS WERE SCATTERED ACROSS BANNER
AND SCOTTS BLUFF COUNTIES OF THE CENTRAL AND SOUTHERN NEBRASKA
PANHANDLE.

BRIEF HEAVY RAIN...STRONG GUSTY WIND AND SMALL HAIL ARE POSSIBLE WITH
THESE STORMS AS THEY MOVE NORTHWEST ACROSS KIMBALL...BANNER AND SCOTTS
BLUFF COUNTIES UNTIL 630 PM MDT.
KIRK
Special weather statement, Jun 1, 6:36 PM MDT, 1 hour 14 minutes before
NEZ001-005-011-020130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SCOTTSBLUFF NE
635 PM MDT SAT JUN 1 1991

...THUNDERSTORMS OVER THE SOUTHWEST NEBRASKA PANHANDLE...

AT 633 PM MDT...RADAR INDICATED THUNDERSTORMS SCATTERED ACROSS CHEYENNE
...KIMBALL...BANNER AND SCOTTS BLUFF COUNTIES OF THE NEBRASKA PANHANDLE.
THE STRONGEST STORM WAS 35 MILES SOUTHWEST OF SCOTTSBLUFF NEBRASKA OVER
WESTERN BANNER COUNTY OF THE SOUTHERN NEBRASKA PANHANDLE.  ALL THE
STORMS WERE MOVING TO THE NORTHWEST AT 25 MPH.

BRIEF HEAVY RAIN...STRONG GUSTY WIND AND SMALL HAIL ARE POSSIBLE WITH
THESE STORMS AS THEY MOVE NORTHWEST ACROSS CHEYENNE...KIMBALL...BANNER
AND SCOTTSBLUFF COUNTIES OF THE NEBRASKA PANHANDLE[ UNTIL 730 PM MDT.
KIRK
Special weather statement, Jun 1, 7:14 PM MDT, 36 minutes before
WYZ012-016-017-020600-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
715 PM MDT SAT JUN 1 1991

...A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR EXTREME SOUTHEAST
WYOMING AND IS IN EFFECT UNTIL MIDNIGHT THIS EVENING...

A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR GOSHEN...LARAMIE...
PLATTE...SOUTHEAST CONVERSE...EASTERN ALBANY...AND SOUTHERN NIOBRARA
COUNTIES IN SOUTHEAST WYOMING.  THIS WATCH IS IN EFFECT UNTIL MIDNIGHT
THIS SATURDAY EVENING.

PEOPLE IN THE WATCH AREA SHOULD BE PREPARED FOR THE DEVELOPMENT OF
SEVERE THUNDERSTORMS.  THESE STORMS WILL PRODUCE HEAVY RAIN...LARGE
HAIL...DAMAGING WINDS...AND DEADLY LIGHTNING.  IF A STROM APPROACHES
...SEEK SHELTER IkMMEDIATELY.

DJV

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 1, 6:08 PM MDTTornado WarningCYSLaramie52 min
Jun 1, 7:00 PM MDTSevere Thunderstorm WarningCYSLaramie60 min
Jun 1, 10:50 PM MDTFlash Flood WarningCYSGoshen, Laramie, Platte2 hr
Jun 2, 5:33 PM MDTFlash Flood WarningCYSSweetwater4 hr

Nearby

Flash Flood Warnings in Wyoming, 1991Every flash flood warning in 1991

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.