Alert archive / Utah / Flash Flood Warnings in 1986

Flash Flood Warning 11, NWS Salt Lake City, UT

August 25, 1986Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Aug 25, 1986, 10:58 PM MDT for Washington County, Utah. It was in force for 2 hr.

The area

The counties it named.

The facts

Issued
Aug 25, 1986, 10:58 PM MDT (04:58 UTC)
Expired
Aug 26, 1986, 1:00 AM MDT
In force
2 hr
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, 5.0 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 1986-08-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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 1986-08-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -12 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3336 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
19 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 
TTAAOO KSLC 260458
FFWSLC
UTC053-260900-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1058 PM MDT MON AUG 25 1986
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A FLASH FLOOD WARNING
EFFECTIVE UNTIL  100 AM MDT FOR PEOPLE IN THE FOLLOWING COUNTIES:
 
IN SOUTHWEST UTAH
          ..EASTERN WASHINGTON

SATELLITE IMAGERY AND RADAR INDICATE THAT HEAVY THUNDERSHOWER
ACTIVITY IS STILL OCCURRING OVER PORTIONS OF EASTERN WASHINGTON
COUNTY.
 
WHILE ACTIVITY IS EXPECTED TO DIMINISH IN THE NEXT FEW HOURS.. AREAS
OF HEAVY RAIN ON TOP OF RUGGED TERRAIN WILL CONTINUE TO CAUSE FLOOD
PROBLEMS.
 
BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE
THE DA1NGERS 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.
 
RW 0500Z

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 25, 7:07 PM MDT, 3 hours 51 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
707 PM MDT MON AUG 25 1986

                 ...THUNDERSHOWERS IN THE UINTAS...

THUNDERSHOWERS HAVE DRIFTED INTO THE UINTA MOUNTAIN RANGE AREA FROM
WYOMING. SATELLITE IMAGERY SUGGESTS THEY ARE INTENSIFYING.. ESPECIALLY
OVER EASTERN SUMMIT AND DAGGET COUNTIES.

SOME OF THESE THUNDERSHOWERS MAY PRODUCE LOCALLY HEAVY RAINFALL.. ALONG
WITH DANGEROUS LIGHTNING. PEOPLE IN THE RECREATIONAL AREAS OF THE UINTAS
SHOULD BE PREPARED TO MOVE TO HIGHER GROUND IN THE EVENT HEAVY RAINFALL
OCCURS NEARBY. AVOID LOW LYING AREAS WHERE WATER ACCUMULATES.. AND BE
WARY OF ROCK OR MUDSLIDES NEAR STEEPER TERRAIN.

THESE SHOWERS ARE EXPECTED TO DEFCAY WITHIN A COUPLE OF HOURS.. BUT FOR
THE TIME BEING A HEADS UP ATTITUDE IS IN ORDER.

FURTHER STATEMENTS WILL BE ISSUED IF NECESSARY.

RW 0107Z
Special weather statement, Aug 25, 8:38 PM MDT, 2 hours 20 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
835 PM MDT MON AUG 25 1986

               ...THUNDERSHOWERS IN WASHINGTON COUNTY...

AT 815 PM THIS EVENING A COOPERATIVE OBSERVER IN THE LAVERKIN AREA
NORTHEAST OF ST. GEORGE REPORTED 8 TENTHS OF AN INCH OF RAIN IN ONLY
20 MINUTES. THE OBSERVER ALSO NOTED GUSTY WINDS AND QUITE A BIT OF
LIGHTNING. SATELLITE PICTURES INDICATE THE SHOWER IS DRIFTING SLOWLY
SOUTHWESTWARD TOWARDS ST. GEORGE.. AND SHOULD AFFECT OTHER PORTIONS OF
WASHINGTON COUNTY ALONG THE WAY THE NEXT HOUR OR SO.

THIS BAND OF THUNDERSHOWERS MAY PRODUCE LOCALLY HEAVY RAINFALL.. ALONG
WITH DANGEROUS LIGHTNING. PEOPLE IN THE RECREATIONAL AREAS OF WASHINGTON
COUNTY SHOULD BE PREPARED TO MOVE TO HIGHER GROUND IN THE EVENT HEAVY
RAINFALL OCCURS NEARBY. AVOID LOW LYING AREAS WHERE WATER ACCUMULATES..
BE WARY OF ROCK OR MUDSLIDES NEAR STEEPER TERRAIN. IF POSSIBLE.. TAKE
SHELTER AGAINST THE LIGHTNING. SMALL HAIL AND WIND GUSTS TO 45 MPH ARE
POSSIBLE.

ALTHOUGH THE SHOWERS ARE EXPECTED TO DIMINISH WITHIN A COUPLE OF
HOURS.. AN EYE TO THE SKY IS RECOMMENDED.

FURTHER STATEMENTS WILL BE ISSUED IF NECESSARY.

RW 0235Z

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 25, 9:17 PM MDTFlash Flood WarningSLCWashington103 min

Nearby

Flash Flood Warnings in Utah, 1986Every flash flood warning in 1986

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.