Alert archive / Utah / Flash Flood Warnings in 1987

Flash Flood Warning 3, NWS Salt Lake City, UT

August 24, 1987Duchesne County, Uintah County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 24, 1987, 7:48 PM MDT for Duchesne County, Uintah County, Utah. It was in force for 117 min.

The area

The counties it named.

The facts

Issued
Aug 24, 1987, 7:48 PM MDT (01:48 UTC)
Expired
Aug 24, 1987, 9:45 PM MDT
In force
117 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties

Counties Duchesne County, UT, Uintah County, UT

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

Grand Junction, CO (KGJT), launched 00:00Z, 1.8 hours before the alert went out and 174 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, Grand Junction, CO at 00:00Z on 1987-08-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 338 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Grand Junction, CO at 00:00Z on 1987-08-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 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
338 J/kg
Mixed-layer CIN
-25 J/kg
Mixed-layer LCL
943 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
4 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 KSLC 250148
FFWSLC
UTC013-047-250345-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
748 PM MDT MON AUG 24 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A FLASH FLOOD WARNING
EFFECTIVE UNTIL  945 PM MDT FOR PEOPLE IN THE FOLLOWING COUNTIES...
 
IN NORTHEAST UTAH
          ...EASTERN DUCHESNE...UINTAH
 
THE UTAH HIGHWAY PATROL REPORTS PORTIONS OF HIGHWAY 40 UNDER 6 INCHES
OF WATER IN THE BRIDGELAND AREA.  HEAVY RAINFALL IS EXPECTED TO
CONTINUE OVER THE WARNING AREA FOR THE NEXT 2 HOURS.  THE HEAVIEST
THUNDERSHOWERS WERE LOCATED OVER EASTERN DUCHESNE COUNTY...AND WERE
MOVING SLOWLY EASTWARD INTO UINTAH COUNTY.
 
 
A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT.  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 RIS9ING WATER MOVE UP TO HIGHER GROUND.
 
ERC/PD....0145Z.

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, Aug 24, 3:20 PM MDT, 4 hours 28 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY
320 PM MDT MON AUG 24 1987

   ...NUMEROUS THUNDERSHOWERS DEVELOPING AGAIN OVER UTAH...

THUNDERSHOWERS WERE DEVELOPING RAPIDLY OVER MUCH OF UTAH AGAIN
EARLY THIS AFTERNOON. THE MOST ACTIVE AREA IS IN THE WESTERN HALF
OF THE STATE AND OVER THE SOUTHERN MOUNTAINS. AN UPPER LEVEL
DISTURBANCE MOVING OUT OF NEVADA WAS ENHANCING THE ACTIVITY IN THESE
AREAS.

GRANTSVILLE REPORTED A HALF INCH OF RAIN IN A 25 MINUTE LONG SHOWER
ABOUT 2 PM AND SHORTLY AFTER THAT BRIEF HEAVY RAIN AND SMALL HAIL
WERE REPORTED AT THE HIGHWAY PATROL CHECKING STATION SOUTH OF
ST. GEORGE.

THE AIRMASS OVER THE STATE REMAINS VERY MOIST AND UNSTABLE. THUS THE
POTENTIAL FOR LOCALLY HEAVY SHOWERS AND SMALL HAIL EXISTS ANYWHERE IN
THE STATE. FREQUENT LIGHTNING IS ALSO LIKELY WITH SOME OF THESE
THUNDERSTORMS. THIS THREAT WILL CONTINUE INTO THE EVENING HOURS THEN

PERSONS ENGAGED IN OUTDOOR ACTIVITIES SHOULD BE PREPARED TO TAKE COVER
IF THESE THUNDERSTORMS APPROACH THEIR AREA.

FURTHER STATEMENTS WILL BE ISSUED AS NEEDED.

DRS...2119Z
Special weather statement, Aug 24, 3:33 PM MDT, 4 hours 15 minutes before
SPECIAL WEATHER STATEMENT...CORRECTION
NATIONAL WEATHER SERVICE SALT LAKE CITY
310 PM MDT MON AUG 24 1987

   ...NUMEROUS THUNDERSHOWERS DEVELOPING AGAIN OVER UTAH...

THUNDERSHOWERS WERE DEVELOPING RAPIDLY OVER MUCH OF UTAH AGAIN
EARLY THIS AFTERNOON. THE MOST ACTIVE AREA IS IN THE WESTERN HALF
OF THE STATE AND OVER THE SOUTHERN MOUNTAINS. AN UPPER LEVEL
DISTURBANCE MOVING OUT OF NEVADA WAS ENHANCING THE ACTIVITY IN THESE
AREAS.

GRANTSVILLE REPORTED A HALF INCH OF RAIN IN A 25 MINUTE LONG SHOWER
ABOUT 2 PM AND SHORTLY AFTER THAT BRIEF HEAVY RAIN AND SMALL HAIL
WERE REPORTED AT THE HIGHWAY PATROL CHECKING STATION SOUTH OF
ST. GEORGE.

THE AIRMASS OVER THE STATE REMAINS VERY MOIST AND UNSTABLE. THUS THE
POTENTIAL FOR LOCALLY HEAVY SHOWERS AND SMALL HAIL EXISTS ANYWHERE IN
THE STATE. FREQUENT LIGHTNING IS ALSO LIKELY WITH SOME OF THESE
THUNDERSTORMS. THIS THREAT WILL CONTINUE INTO THE EVENING HOURS THEN
GRADUALLY DECREASE FROM THE WEST ATER TONIGHT.

PERSONS ENGAGED IN OUTDOOR ACTIVITIES SHOULD BE PREPARED TO TAKE COVER
IF THESE THUNDERSTORMS APPROACH THEIR AREA.

FURTHER STATEMENTS WILL BE ISSUED AS NEEDED.

DRS...2112Z   ...CORRECTION FOR MISSING LINE 3RD PARAGRAPH...

The office that day

Everything else NWS Salt Lake City, UT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 25, 1:05 PM MDTTornado WarningSLCCache55 min

Nearby

Flash Flood Warnings in Utah, 1987Every flash flood 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.