Alert archive / Utah / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 72, NWS Salt Lake City, UT

August 12, 1997Emery County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Aug 12, 1997, 1:20 PM MDT for Emery County, Utah. It was in force for 35 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Aug 12, 1997, 1:20 PM MDT (19:20 UTC)
Expired
Aug 12, 1997, 1:55 PM MDT
In force
35 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties

County Emery County, UT

The radar

The Grand Junction radar (KGJX), 215 km from the middle of the area, began a volume at 19:23 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Aug 12, 1:30 PM MDTThunderstorm Wind 61Green River, UT

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Grand Junction, CO (KGJT), launched 12:00Z, 7.3 hours before the alert went out and 191 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 1997-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 8 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 1997-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 77 square meters per square second.1939587897Sfc1 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
8 J/kg
Mixed-layer CIN
-269 J/kg
Mixed-layer LCL
1458 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
77 m²/s²
0-3 km storm-relative helicity
106 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.

017 
WUUS1 KSLC 121922 RRA
SVRSLC
UTC015-121955-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
120 PM MDT TUE AUG 12 1997

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY UT HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 155 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN CENTRAL UTAH

   ...EASTERN EMERY COUNTY
 
AT 115 PM MDT...A SEVERE THUNDERSTORM WAS INDICATED BY DOPPLER
RADAR 19 MILES WEST OF GREEN RIVER MOVING EAST AT 20 MPH.
A SECOND STRONG STORM WAS LOCATED ABOUT 20 MILES SOUTH OF GREEN
RIVER.

THE STRONGER STORM IS EXPECTED TO MOVE JUST NORTH OF GREEN RIVER AT
ABOUT 140 PM.  THE OTHER STORM IS EXPECTED TO REMAIN IN RURAL
AREAS
 
THESE STORMS MAY PRODUCE STRONG GUSTY WIND...LARGE HAIL...AND
FREQUENT LIGHTNING.  TAKE COVER WHEN THREATENING WEATHER APPROACHES.

HEAVY THUNDERSTORM RAINS CAN QUICKLY FLOOD ROADS.  DO NOT ATTEMPT TO
DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 10:48 PM MDTSevere Thunderstorm WarningSLCKane62 min
Aug 12, 3:13 PM MDTSevere Thunderstorm WarningSLCGarfield47 min
Aug 12, 3:59 PM MDTSevere Thunderstorm WarningSLCGarfield46 min
Aug 12, 4:48 PM MDTSevere Thunderstorm WarningSLCJuab, Tooele62 min
Aug 12, 5:51 PM MDTSevere Thunderstorm WarningSLCTooele64 min

Nearby

Severe Thunderstorm Warnings in Utah, 1997Every severe thunderstorm warning in 1997

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.