Alert archive / Utah / Flash Flood Warnings in 1990

Flash Flood Warning 6, NWS Salt Lake City, UT

September 3, 1990Iron County, Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Sep 3, 1990, 7:01 PM MDT for Iron County, Washington County, Utah. It was in force for 71 min.

The area

The counties it named.

The facts

Issued
Sep 3, 1990, 7:01 PM MDT (01:01 UTC)
Expired
Sep 3, 1990, 8:12 PM MDT
In force
71 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties

Counties Iron County, UT, Washington 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

Ely/Yelland Fld, NV (KELY), launched 00:00Z, 1.0 hours before the alert went out and 226 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, Ely/Yelland Fld, NV at 00:00Z on 1990-09-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 153 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, Ely/Yelland Fld, NV at 00:00Z on 1990-09-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 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
153 J/kg
Mixed-layer CIN
-46 J/kg
Mixed-layer LCL
2605 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
32 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 040104
FFWSLC
UTC021-053-040300-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
701 PM MDT MON SEP 3 1990
 
THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  900 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHWEST UTAH
 
   ...IRON COUNTY...NORTHERN WASHINGTON COUNTY
 
THE UTAH HIGHWAY PATROL IN ST GEORGE REPORTED 1.5 INCHES OF RAIN
BETWEEN 600 PM AND 645 PM. ALTHOUGH THERE HAVE BEEN NO REPORTS OF
FLOODING..RAINFALL AMOUNTS OF THIS MAGNITUDE IN SUCH A SHORT TIME
FREQUENTLY PRODUCE FLOODING. THUS A FLASH FLOOD WARNING IS IN EFFECT
UNTIL 900 PM FOR NORTHERN WASHINGTON COUNTY AND ALL OF IRON 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 RISING WATER MOVE UP TO HIGHER GROUND.
 
SMITH  0102Z

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, Sep 3, 5:49 PM MDT, 1 hour 12 minutes before
UTC025-037-053-040145-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
548 PM MDT MON SEP 3 1990

AN AREA OF THUNDERSTORMS IS MOVING NORTHWARD OUT OF ARIZONA INTO THE
SOUTHERN PORTIONS OF WASHINGTON..KANE..AND SAN JUAN COUNTIES. THESE
THUNDERSTORMS HAVE THE POTENTIAL FOR BRIEF HEAVY RAIN..DANGEROUS
LIGHTNING..AND STRONG GUSTY WINDS.

THE THUNDERSTORMS ARE MOVING NORTHWARD ABOUT 10-15 MPH. PERSONS IN
SOUTHERN UTAH SHOULD KEEP WATCH FOR THESE THUNDERSTORMS AS THEY MOVE
INTO THE STATE. WHEN THUNDERSTORMS BEGIN..FIND SHELTER UNTIL THE
STORM PASSES. BOATERS ON LAKE POWELL SHOULD SEEK SAFE HARBOR WHEN
STORMS APPROACH.

SMITH 2348Z

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 4, 5:46 PM MDTFlash Flood WarningSLCMorgan59 min

Nearby

Flash Flood Warnings in Utah, 1990Every flash flood warning in 1990

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.