Alert archive / Utah / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 23, NWS Grand Junction, CO

August 29, 2002Uintah County, Utah

NWS Grand Junction, CO issued this severe thunderstorm warning at Aug 29, 2002, 1:32 PM MDT for Uintah County, Utah. It was in force for 43 min. 2 reports 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 29, 2002, 1:32 PM MDT (19:32 UTC)
Expired
Aug 29, 2002, 2:15 PM MDT
In force
43 min
Issued by
NWS Grand Junction, CO
Area
Counties, with a storm outline in the text

County Uintah County, UT

What was reported inside it

TimeReportWhereRemark
Aug 29, 2:00 PM MDTHail 0.75Randlett, UT
Aug 29, 2:25 PM MDTHail 0.88Randlett, 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 29, 1:05 PM MDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Grand Junction, CO (KGJT), launched 12:00Z, 7.5 hours before the alert went out and 141 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 2002-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 203 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 2002-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 square meters per square second.1939587897117Sfc1 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
203 J/kg
Mixed-layer CIN
-177 J/kg
Mixed-layer LCL
2205 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
82 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

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.

NWS Grand Junction, CO wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 29, 2:30 AM MDT, 11 hours 2 minutes earlier.

Area forecast discussion, Aug 29, 2:30 AM MDT, 11 hours 2 minutes before
WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
230 AM MDT THU AUG 29 2002

LOW PRESSURE SYSTEM OVER THE WESTERN GREAT BASIN TO EJECT NORTH-
EASTWARD INTO THE NORTHERN PLAINS TODAY AND INTO TONIGHT. JET NOSING
INTO THE FOUR CORNERS ALREADY GENERATING SHOWERS AND THUNDERSTORMS
ACROSS SOUTHWESTERN CWFA. SO FAR...RAINFALL LIGHT BUT WINDS GUSTY AS
MID-LEVELS STILL RATHER DRY. DEWPOINT VALUES HAVE COME UP FROM
YESTERDAY OVER THE FOUR CORNERS...EXTENDING NORTH TO THE GRAND VALLEY
THIS MORNING. AS A RESULT...EXPECT NOT ALL THUNDERSTORMS TO BE DRY.
NONETHELESS...FIRE WEATHER STILL A MAJOR CONCERN WITH WATCH ALREADY
IN PLACE APPEARING WELL WARRANTED. WILL LET DAY SHIFT SETTLE DETAILS
OF POSSIBLE RED FLAG WARNING.

PRESENT FORECAST FOR TODAY APPEARS ON TRACK. MODELS CONTINUE TO SHOW
SHORTWAVE ENERGY AND JET INFLUENCE TO BE THE STORY TODAY. GIVEN
DEWPOINT FIELD ALLUDED TO ABOVE...WILL CONTINUE WITH BEST POPS OVER
THE SOUTHERN MOUNTAINS AND SCATTERED POPS ELSEWHERE. CLOUD COVER WILL
KEEP TEMPERATURES DOWN AND APPEARS MET DATA HAS GOOD HANDLE ON THE
SITUATION.

WAVE PUSHES EAST OF THE AREA TONIGHT...SO EXPECT SOME LINGERING
EVENING CONVECTION...THEN DRY AND CLEARING DURING THE REMAINDER OF
THE NIGHT TONIGHT. DRIER...SLIGHTLY MORE STABLE ENVIRONMENT IN PLACE
ON FRIDAY...THOUGH RESIDUAL MOISTURE AND INCREASED INSOLATION WILL
LIKELY YIELD SOME AFTERNOON/EVENING THUNDERSTORMS OVER THE HIGHER
TERRAIN. TEMPS SHOULD REBOUND WITH RETURN OF SUNSHINE AND MET
GUIDANCE AGAIN APPEARS TO HAVE GOOD HANDLE ON THE EVOLVING PATTERN.
LITTLE CHANGE INDICATED FOR SATURDAY. NL

EXTENDED (SUN-WED)...AVN HAS REMNANTS OF WESTERN TROF LIFTING
NORTHEAST ACROSS THE FORECAST AREA ON TUE...WHILE UPPER HIGH REMAINS
OVER NRN MEXICO/SRN NM THROUGH PERIOD. WILL CONTINUE WITH FORECAST OF
SWLY FLOW UNTIL THEN BASED ON AVN WITH SOME MID/HIGH LEVEL PACIFIC
MOISTURE ENTRAINED ACROSS THE AREA BEGINNING SUNDAY...AND THUS WILL
KEEP MENTION OF SLIGHT CHANCE FOR NOW ON SUN-MON ASSUMING ALSO SOME
WEAK EMBEDDED DISTURBANCES IN THE FLOW. THEN BETTER CHANCE FOR TUE AS
TROUGH LIFTS OUT. HOWEVER...ECWMF SHOWING MORE RIDGING OVER THE AREA
ON MONDAY WITH TROUGH NOW FARTHER WEST IMPLYING DRIER CONDITIONS...SO
WILL HAVE TO WATCH EVOLUTION.  JAD

.GJT...FIRE WEATHER WATCH THURSDAY FROM 1100 THROUGH 2200 MDT
       FOR ALL FIRE WX ZONES IN EASTERN UTAH AND WESTERN COLORADO.

The office that day

Everything else NWS Grand Junction, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 29, 11:59 AM MDTFlash Flood WarningGJTLa Plata3 hr
Aug 29, 2:59 PM MDTFlash Flood WarningGJTLa Plata3 hr
Aug 29, 5:58 PM MDTSevere Thunderstorm WarningGJTMesa47 min
Aug 29, 2:11 PM MDTSevere Thunderstorm WarningGJTUintah49 min
Aug 29, 2:56 PM MDTSevere Thunderstorm WarningGJTUintah49 min
Aug 29, 3:02 PM MDTSevere Thunderstorm WarningGJTGrand43 min
Aug 29, 3:46 PM MDTSevere Thunderstorm WarningGJTGrand44 min
Aug 29, 5:15 PM MDTFlash Flood WarningGJTSan Juan3 hr
Aug 29, 5:31 PM MDTSevere Thunderstorm WarningGJTSan Juan44 min

Nearby

Severe Thunderstorm Warnings in Utah, 2002Every severe thunderstorm warning in 2002

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.