Alert archive / Utah / Flash Flood Warnings in 1991

Flash Flood Warning 4, NWS Salt Lake City, UT

August 3, 1991Garfield County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 3, 1991, 4:33 PM MDT for Garfield County, Utah. It was in force for 117 min.

The area

The counties it named.

The facts

Issued
Aug 3, 1991, 4:33 PM MDT (22:33 UTC)
Expired
Aug 3, 1991, 6:30 PM MDT
In force
117 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties

County Garfield County, UT

The nearest sounding before it

Grand Junction, CO (KGJT), launched 12:00Z, 10.6 hours before the alert went out and 293 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 12:00Z on 1991-08-03Temperature 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 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 12:00Z on 1991-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 26 square meters per square second.193958Sfc1 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
1443 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
27 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 032235
FFWSLC
UTC017-040030-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
433 PM MDT SAT AUG 3 1991
 
THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  630 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION......
 
IN SOUTH CENTRAL UTAH
 
   ...CENTRAL AND EASTERN GARFIELD COUNTY
 
VERY HEAVY RAIN THE PAST 1-2 HOURS HAS CAUSED WIDESPREAD MUDSLIDES
AND FLOODING IN THE CANYONS AROUND THE ESCALANTE AND BOULDER AREAS OF
GARFIELD COUNTY. HEAVY RAINS CONTINUE AT THIS TIME AND A WORSENING
FLOOD SITUATION IS EXPECTED FOR THE NEXT COUPLE OF HOURS.
 
DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY.  THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY.  VEHICLES CAUGHT IN RISING WATER SHOULD BE
ABANDONED QUICKLY.  MOVE TO HIGHER GROUND.

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 3, 1:53 PM MDT, 2 hours 40 minutes before
UTZALL-040000-
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
145 PM MDT SAT AUG 3 1991

 ...STRONG THUNDERSTORMS OVER SOUTHWESTERN UTAH THIS AFTERNOON...

STRONG THUNDERSTORMS HAVE DEVELOP OVER MUCH OF SOUTHWESTERN UTAH
EARLY THIS AFTERNOON.  THE STRONGEST STORMS WERE ALONG THE
NEVADA/UTAH BORDER FROM ABOUT 70 MILES SOUTH OF WENDOVER TO JUST
NORTHWEST OF MILFORD.  ANOTHER AREA OF STRONG THUNDERSTORMS ARE
OVER THE SOUTHERN MOUNTAINS FROM JUST EAST OF CEDAR CITY TO NEAR
MANTI UTAH.  ALL STORMS WERE MOVING TO THE NORTH-NORTHEAST AROUND
15 MPH.

RADAR INDICATES THAT THESE STORMS ARE PRODUCING LIGHT TO MODERATE
AMOUNTS OF RAIN.  BECAUSE OF THE SLOW MOVEMENT OF THESE STORMS...
RAINFALLS IN THE ONE QUARTER TO ONE HALF INCH RANGE ARE POSSIBLE IN A
SHORT PERIOD OF TIME.  THESE RAINFALLS COULD PRODUCE SOME LOCALIZED
FLOODING OF ROADWAYS AND IN LOW LYING AREAS PRONE TO FLOODING.

THESE STORMS ARE ALSO PRODUCING FREQUENT CLOUD-TO-GROUND LIGHTNING.
IF STORMS APPROACH...SEEK SHELTER IMMEDIATELY TO AVOID BEING STRUCK
BY LIGHTNING.

THIS AFTERNOONS THUNDERSTORM ACTIVITY WILL CONTINUE TO MOVE NORTHWARD
THROUGH THIS EVENING. THUNDERSTORMS SHOULD REACH THE WASATCH FRONTt
LATE THIS AFTERNOON AND WILL STILL BE PACKING FREQUENT LIGHTNING AND
BRIEF HEAVY RAINFALLS.

FURTHER STATEMENTS WILL ISSUED AS NECESSARY.

MCC...1945Z

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 3, 3:28 PM MDTSevere Thunderstorm WarningSLCJuab47 min
Aug 3, 5:52 PM MDTFlash Flood WarningSLCWayne68 min

Nearby

Flash Flood Warnings in Utah, 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.