Alert archive / Utah / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 4, NWS Salt Lake City, UT

July 20, 1986Garfield County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Jul 20, 1986, 5:01 PM MDT for Garfield County, Utah. It was in force for 59 min.

The area

The counties it named.

The facts

Issued
Jul 20, 1986, 5:01 PM MDT (23:01 UTC)
Expired
Jul 20, 1986, 6:00 PM MDT
In force
59 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties

County Garfield 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

Grand Junction, CO (KGJT), launched 12:00Z, 11.0 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 1986-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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, Grand Junction, CO at 12:00Z on 1986-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 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
2 J/kg
Mixed-layer CIN
-303 J/kg
Mixed-layer LCL
1923 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
110 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 202301
SVRSLC
UTC017-210000-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
501 PM MDT SUN JUL 20 1986
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL  600 PM MDT FOR PEOPLE IN THE FOLLOWING COUNTIES:
 
IN SOUTH CENTRAL UTAH
          ..CENTRAL GARFIELD

A WEATHER OBSERVER IN ESCALANTE REPORTED ONE INCH HAIL BETWEEN 4PM
AND 445 PM THIS AFTERNOON ALONG WITH A FUNNEL CLOUD. THIS IS THE
RESULT OF HEAVY THUNDERSTORMS OVER CENTRAL GARFIELD COUNTY. OTHER
REPORTS OF LARGE HAIL HAVE BEEN RECEIVED IN SOUTHERN UTAH AND
NORTHERN ARIZONA THIS AFTERNOON.
 
IF YOU ARE CAUGHT OUTSIDE, SEEK SHELTER FROM THE WEATHER IN A
STRONG BUILDING.  DAMAGING WIND, LARGE HAIL, VERY HEAVY RAIN, AND
DEADLY LIGHTNING ARE ALL POSSIBLE IN SEVERE THUNDERSTORMS.  STAY
INSIDE AWAY FROM WINDOWS UNTIL THE STOR3M HAS PASSED.
 
ERC 20/2301Z

What forecasters said that day

The local office's own words before this severe thunderstorm 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, Jul 20, 12:30 PM MDT, 4 hours 31 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1230 PM MDT SUN JUL 20 1986

   ...THUNDERSHOWERS RUMBLING IN THE SOUTHWEST PORTION OF UTAH...

A MOIST UNSTABLE AIRMASS IS PRODUCING SCATTERED THUNDERSHOWERS IN
MAINLY SOUTHWEST UTAH AT THIS TIME WITH SOME ACTIVITY OVER THE
UINTAH MOUNTAINS OF NORTHERN UTAH. LIGHTNING DECTECTION EQUIPMENT
INDICATES FREQUENT LIGHTNING IS OCCURRING FROM THESE CELLS.

A REPORT WAS JUST RECEIVED FROM A WEATHER SPOTTER IN THE DUCK CREEK
AREA OF SOUTHERN UTAH JUST EAST OF NAVAJO LAKE. HE INDICATED LITTLE
RAINFALL BUT A CONSIDERABLE AMOUNT OF HAIL. THE HAIL COVERED THE
GROUND ABOUT A 1/2 INCH IN SOME PLACES WITH PEA-SIZE DIAMETER HAIL
WITH A FEW UP TO GOLF-BALL SIZE.

MODERATE RAINFALL IS LIKELY THIS AFTERNOON IN PORTIONS OF SOUTHERN
UTAH WITH SOME LOCALIZED HEAVY RAINFALL POSSIBLE AND SMALL HAIL.

REMEMBER..LIGHTNING KILLS. DON`T BE A HUMAN LIGHTNING ROD. LIGHTNING
NORMALLY STRIKES THE XTALLEST OBJECT IN THE AREA. SEEK PROPER PROTECTION
WHEN LIGHTNING/THUNDER ARE IN THE AREA SUCH AS A CAR OR A BUILDING.

FURTHER STATEMENTS WILL BE ISSUED AS REQUIRED.

WJA/AX 1830Z....

Nearby

Severe Thunderstorm Warnings in Utah, 1986Every severe thunderstorm 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.