Alert archive / Utah / Flash Flood Warnings in 1993

Flash Flood Warning 2, NWS Salt Lake City, UT

August 10, 1993Utah County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 10, 1993, 4:40 PM MDT for Utah County, Utah. It was in force for 60 min.

The area

The counties it named.

The facts

Issued
Aug 10, 1993, 4:40 PM MDT (22:40 UTC)
Expired
Aug 10, 1993, 5:40 PM MDT
In force
60 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties

County Utah County, UT

The nearest sounding before it

Salt Lake City I, UT (KSLC), launched 12:00Z, 10.7 hours before the alert went out and 76 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, Salt Lake City I, UT at 12:00Z on 1993-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 138 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, Salt Lake City I, UT at 12:00Z on 1993-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 92 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
138 J/kg
Mixed-layer CIN
-238 J/kg
Mixed-layer LCL
1828 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
92 m²/s²
0-3 km storm-relative helicity
117 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 102243
FFWSLC
UTC049-055-102340-

BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
440 PM MDT TUE AUG 10 1993

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A 
FLASH FLOOD WARNING EFFECTIVE UNTIL  530 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...

IN CENTRAL UTAH

   ...NORTHERN UTAH COUNTY

IN SOUTH CENTRAL UTAH

   ...EAST CENTRAL WAYNE COUNTY

HEAVY THUNDERSTORMS IN NORTHERN UTAH COUNTY HAS CAUSED LOCAL FLOODING
OF STREETS AND ROADWAYS.  RAINFALL REPORTS RECEIVED WERE 1.03 IN 15
MINUTES IN LEHI AND .62 OF AN INCH IN 15 MINUTES IN AMERICAN FORK. 
THESE THUNDERSTORMS ARE MOVING TO THE NORTHEAST AT 35 MPH AND WILL BE
AFFECTING THE NORTHERN END OF UTAH COUNTY INCLUDING THE CITIES OF
LEHI...ALPINE...HIGHLAND...AMERICAN FORK AND AMERICAN FORK CANYON. 

IN SOUTH CENTRAL UTAH THE HIGHWAY PATROL REPORTS WATER RUNNING OVER
THE ROAD ON STATE ROUTE 95 ABOUT 4 MILES SOUTH OF HANKSVILLE. 
THUNDERSTORMS IN THE AREA ARE MOVING NORTHEAST AT 35 MPH AND WILL
AFFECT THOSE PEOPLE TRAVELING ON STATE ROUTE 95 AND CAMPERS AND
HIKERS IN NEAR THE MUDDY AND DIRTY DEVIL RIVERS IN EASTERN WAYNE
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.

FURTHER STATEMENTS WILL BE ISSUED AS NEEDED.

SMITH...2241Z

&

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 10, 2:11 PM MDT, 2 hours 29 minutes before
UTZALL-102030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
220 PM MDT TUE AUG 10 1993

...STRONG THUNDERSTORMS DEVELOPING OVER WESTERN UTAH...

STRONG THUNDERSTORMS ARE DEVELOPING OVER WESTERN UTAH THIS AFTERNOON.
THESE STORMS ARE PRODUCING LOCAL AREAS OF HEAVY RAIN AND FREQUENT
LIGHTNING.  ONE HALF INCH OF RAIN IN TEN MINUTES WAS REPORTED NEAR
DELTA AROUND 1 PM THIS AFTERNOON. LIGHTNING DETECTION EQUIPMENT
INDICATES NUMEROUS LIGHTNING STRIKES WITH THESE STORMS...WITH SOME
THUNDERSTORMS PRODUCING NEARLY 2 STRIKES PER MINUTE.  THUNDERSTORMS
WILL CONTINUE TO DEVELOP THIS AFTERNOON AND CONTINUE AFTER DARK.

IF THUNDERSTORMS APPROACH...SEEK SHELTER INDOORS.  BEWARE OF~
LIGHTNING WHICH IS UTAHS BIGGEST WEATHER RELATED KILLER.

FURTHER STATEMENTS WILL BE ISSUED AS NEEDED.
LBD 2010 UTC
Special weather statement, Aug 10, 2:20 PM MDT, 2 hours 20 minutes before
UTZALL-102030-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
220 PM MDT TUE AUG 10 1993

...STRONG THUNDERSTORMS DEVELOPING OVER WESTERN UTAH...

STRONG THUNDERSTORMS ARE DEVELOPING OVER WESTERN UTAH THIS AFTERNOON.
THESE STORMS ARE PRODUCING LOCAL AREAS OF HEAVY RAIN AND FREQUENT
LIGHTNING.  ONE HALF INCH OF RAIN IN TEN MINUTES WAS REPORTED NEAR
DELTA AROUND 1 PM THIS AFTERNOON. LIGHTNING DETECTION EQUIPMENT
INDICATES NUMEROUS LIGHTNING STRIKES WITH THESE STORMS...WITH SOME
THUNDERSTORMS PRODUCING NEARLY 2 STRIKES PER MINUTE.  THUNDERSTORMS
WILL CONTINUE TO DEVELOP THIS AFTERNOON AND CONTINUE AFTER DARK.

IF THUNDERSTORMS APPROACH...SEEK SHELTER INDOORS.  BEWARE OF
LIGHTNING WHICH IS UTAHS BIGGEST WEATHER RELATED KILLER.

FURTHER STATEMENTS WILL BE ISSUED AS NEEDED.
LBD 2010 UTC
Special weather statement, Aug 10, 3:55 PM MDT, 45 minutes before
UTZALL-110000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
355 PM MDT TUE AUG 10 1993

...HEAVY RAINFALL AND HAIL IN THE SALT LAKE VALLEY...

STRONG THUNDERSTORMS HAVE DROPPED HEAVY RAIN AND SMALL HAIL IN THE
SALT LAKE VALLEY.  SINCE 3 PM MDT NUMEROUS REPORTS OF BETWEEN ONE
THIRD AND ONE HALF INCHES OF RAIN HAVE BEEN RECEIVED WITH GREATER
AMOUNTS IN THE SOUTH END OF THE VALLEYS.  IN SOUTH JORDAN ONE INCH OF
RAIN WAS REPORTED IN 15 MINUTES WHILE IN RIVERTON /.70/ FELL IN THE
SAME TIME PERIOD.  HAIL REPORTS RANGED FROM 1/4 INCH DIAMETER UP TO
5/8 INCH DIAMETER NEAR LITTLE COTTONWOOD CANYON.

THESE THUNDERSTORMS WILL CONTINUE ACROSS UTAH THE REST OF THIS EVENING.
PERSONS EXPERIENCING THESE STORMS CAN EXPECT HEAVY RAIN...HAIL AND
FREQUENT CLOUD-TO-GROUND LIGHTNING.  IF A STORM APPROACHES THE BEST
SHELTER IS INDOORS AWAY FROM WINDOWS.  AVOID OPEN AREAS OR TALL..
ISOLATED TREES TO PREVENT BEING STRUCK BY LIGHTNING.

MCC...2155Z
Special weather statement, Aug 10, 3:56 PM MDT, 44 minutes before
UTZALL-110000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
355 PM MDT TUE AUG 10 1993

...HEAVY RAINFALL AND HAIL IN THE SALT LAKE VALLEY...

STRONG THUNDERSTORMS HAVE DROPPED HEAVY RAIN AND SMALL HAIL IN THE
SALT LAKE VALLEY.  SINCE 3 PM MDT NUMEROUS REPORTS OF BETWEEN ONE
THIRD AND ONE HALF INCHES OF RAIN HAVE BEEN RECEIVED WITH GREATER
AMOUNTS IN THE SOUTH END OF THE VALLEYS.  IN SOUTH JORDAN ONE INCH OF
RAIN WAS REPORTED IN 15 MINUTES WHILE IN RIVERTON /.70/ FELL IN THE
SAME TIME PERIOD.  HAIL REPORTS RANGED FROM 1/4 INCH DIAMETER UP TO
5/8 INCH DIAMETER NEAR LITTLE COTTONWOOD CANYON.

THESE THUNDERSTORMS WILL CONTINUE ACROSS UTAH THE REST OF THIS EVENING.
PERSONS EXPERIENCING THESE STORMS CAN EXPECT HEAVY RAIN...HAIL AND
FREQUENT CLOUD-TO-GROUND LIGHTNING.  IF A STORM APPROACHES THE BEST
SHELTER IS INDOORS AWAY FROM WINDOWS.  AVOID OPEN AREAS OR TALL..
ISOLATED TREES TO PREVENT BEING STRUCK BY LIGHTNING.

MCC...2155Z

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 8:10 PM MDTFlash Flood WarningSLCWayne110 min
Aug 10, 4:40 PM MDTFlash Flood WarningSLCWayne60 min

Nearby

Flash Flood Warnings in Utah, 1993Every flash flood warning in 1993

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.