Alert archive / Utah / Flash Flood Warnings in 1990

Flash Flood Warning 2, NWS Salt Lake City, UT

August 16, 1990Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 16, 1990, 4:30 AM MDT for Washington County, Utah. It was in force for 90 min.

The area

The counties it named.

The facts

Issued
Aug 16, 1990, 4:30 AM MDT (10:30 UTC)
Expired
Aug 16, 1990, 6:00 AM MDT
In force
90 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties

County 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

Mercury/Desert R, NV (KDRA), launched 00:00Z, 10.5 hours before the alert went out and 234 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, Mercury/Desert R, NV at 00:00Z on 1990-08-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 366 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, Mercury/Desert R, NV at 00:00Z on 1990-08-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 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
366 J/kg
Mixed-layer CIN
-28 J/kg
Mixed-layer LCL
2247 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
33 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 161034
FFWSLC
UTC053-161200-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
430 AM MDT THU AUG 16 1990
 
THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  600 AM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION......
 
IN EXTREME SOUTHWEST UTAH
 
   ...EASTERN AND SOUTHERN WASHINGTON COUNTY
 
IN ADDITION TO WATER AND MUD COVERING INTERSTATE 15 SOUTHWEST OF ST
GEORGE ABOUT SIX MILES NORTH OF THE ARIZONA BORDER, A LA VERKIN
PRECIPITATION SPOTTER REPORTED 1.30 OF RAIN IN 30 MINUTES. A LARGE
THUNDERSTORM COMPLEX IS MOVING SLOWLY EASTWARD ACROSS THE AREA.
 
 
BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE
THE DANGERS OF FLOODS AND FLASH FLOODS.  IF FLASH FLOODING IS
OBSERVED...ACT QUICKLY.  MOVE UP TO ESCAPE FLOOD WATERS.  DO
NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.
 
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.
 
MOST DEATHS IN FLASH FLOODING 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.

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 3:40 AM MDTFlash Flood WarningSLCWashington2 hr

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.