Severe Thunderstorm Warning 28, NWS Salt Lake City, UT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
355 PM MDT WED JUL 7 2004

.SYNOPSIS...A WEAK COLD FRONT WILL PUSH SOUTH INTO CENTRAL UTAH BY
TOMORROW...WITH DRY SOUTHWEST FLOW ELSEWHERE.  THE FRONT WILL WEAKEN
AND SOUTHWEST FLOW WILL RETURN TO THE ENTIRE AREA THURSDAY NIGHT AND
FRIDAY.

&&

.DISCUSSION...ANOMALOUS UPPER LEVEL PATTERN FOR JULY CONTINUES IN
THE WEST.  UPPER TROUGH OVER BRITISH COLUMBIA CANADA CURRENTLY
EJECTING A SHORT WAVE THAT SHOWS UP NICELY IN WV IMAGERY OVER
NORTHEAST WASHINGTON STATE SLIDING EAST. COLD FRONT OUT AHEAD OF
THIS SHORT WAVE HAS PUSHED INTO NORTHWEST UTAH THIS AFTERNOON WITH
CONVECTION FORMING ALONG THE CONVERGENCE ZONE FORMED BY THE FRONT
AND SOUTHWESTERLY FLOW OUT AHEAD.  WENDOVER HAS BEEN REPORTING
WESTERLY WINDS FOR THE LAST COUPLE OF HOURS NOW...THOUGH TRUE
FRONTAL BOUNDARY PROBABLY NORTHWEST OF THERE.  COLUMN MOISTURE HAS
BEEN INCREASING THROUGH THE AFTERNOON PER FSL GPS INTEGRATED
PRECIPITABLE WATER VAPOR SENSOR ON SLC WFO ROOF.  MORNING SLC RAOB
HAD JUST UNDER 0.6 IN PW...BUT HAS INCREASED SINCE THEN TO OVER 0.8
INCHES.  THIS AXIS IS RATHER THIN...EXTENDING WEST-EAST ACROSS
NORTHERN NEVADA INTO NORTHERN UTAH.  EXPECT CURRENT CONVECTION TO
CONTINUE INTO EARLY EVENING WITH THE HELP OF THE CONVERGENCE ALONG
THE FRONT.  ETA PUSHES FRONT THROUGH NORTHERN UTAH THIS EVENING
BEFORE WASHING OUT A LITTLE AND STALLING OVER CENTRAL UTAH
TOMORROW.  STILL EXPECT MOST CONVECTION TO PRODUCE LITTLE OR NO RAIN
GIVEN DRY LOW LEVELS AND MOIST MID LEVELS.  AS HEATING DIMINISHES
EXPECT ACTIVITY TO DIMINISH AS WELL...ALTHOUGH SURFACE CONVERGENCE
COULD HELP KEEP THINGS GOING LATER THIS EVENING OVER MAINLY THE
UINTAS AND JUST SOUTH.

SOUTHERN HALF OF FORECAST AREA FAIRLY DRY...PINCHED BETWEEN MOISTURE
IN THE NORTH AND BETTER MOISTURE SOUTH OF THE AREA.  WHAT CU HAS
FORMED IS BASICALLY FLAT.  HAVE LEFT ANY TRW CHANCES OUT FOR THIS
EVENING IN SOUTHWEST MOUNTAINS.

NORTH SHOULD BE COOLER TOMORROW BEHIND FRONTAL BOUNDARY THAT MODELS
LAY SOMEWHERE ACROSS CENTRAL UTAH.  SOME MINOR DIFFERENCES BETWEEN
GFS AND ETA IN TERMS OF TOMORROWS MOISTURE WITH THE GFS WETTER THAN
THE ETA.  UPPER TROUGH AXIS HAS PASSED BY AND INTO EASTERN MONTANA
BY THEN AND FLOW TURNS MORE WESTERLY.  PRECIP WATER DECREASES A
LITTLE WHILE STAYING AROUND HALF AN INCH MOST PLACES.  HAVE LEFT
PREVIOUS FORECAST OF CONVECTION OVER HIGH TERRAIN TOMORROW MAINLY
ACROSS CENTRAL UTAH ALONG WHAT FRONTAL BOUNDARY WILL STILL BE LEFT
AT THAT TIME.

MODELS WANT TO PUSH MOISTURE NORTHWARD OUT OF THE DESERT SOUTHWEST
AND INTO SOUTHERN UTAH BY FRIDAY...ALL OF WHICH AHEAD OF A WEAK
UPPER SHORT WAVE THATS PROGGED TO COME ONSHORE OVER CENTRAL CALIF
TOMORROW NIGHT.  HAVE INTRODUCED SLIGHT CHANCES OF TRW ALONG THE
SOUTHERN TIER FOR FRIDAY WITH THIS MODEL IDEA IN MIND...AND MAY HAVE
TO BE INCREASED DEPENDING ON HOW FUTURE RUNS EVOLVE.  NORTH STAYS
MAINLY DRY FRIDAY.

FOR BEYOND FRIDAY AREA WILL BE IN HOT AND WINDY SOUTHWEST FLOW.
HAVE BUMPED TEMPS UP THROUGH MID WEEK TO REFLECT THIS TREND.  UPPER
JET WILL RUN ACROSS NORTHWEST UTAH BY LATE IN THE WEEKEND AND PRETTY
MUCH REMAIN IN A POSITION TO KEEP US HOT AND WINDY ALL THE WAY
THROUGH THE REMAINDER OF THE FORECAST PERIOD.  WITH MOISTURE PLUME
SHIFTED TO OUR EAST THIS WILL LIKELY INCREASE RED FLAG CONDITIONS
DURING THAT TIME OF THE FORECAST.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...

UT...RED FLAG WARNING UNTIL 10 PM FOR WESTERN UTAH VALLEYS.
WY...NONE.
ID...NONE.

&&

JACKSON

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
600 AM MDT WED JUL 7 2004

IDZ024-025-UTZ001>021-WYZ021-081200-
CACHE VALLEY/IDAHO PORTION-CACHE VALLEY/UTAH PORTION-CASTLE COUNTRY-
CENTRAL AND SOUTHWEST MOUNTAINS-
GLEN CANYON RECREATION AREA/LAKE POWELL-
GREAT SALT LAKE DESERT AND MOUNTAINS-HENRY MOUNTAINS-
NORTHERN WASATCH FRONT-SALT LAKE AND TOOELE VALLEYS-SAN RAFAEL SWELL-
SANPETE/SEVIER VALLEYS-SOUTH CENTRAL UTAH-SOUTHERN WASATCH FRONT-
SOUTHWEST UTAH-SOUTHWEST WYOMING-UTAHS DIXIE AND ZION NATIONAL PARK-
WASATCH MOUNTAIN VALLEYS-WASATCH MOUNTAINS I-80 NORTH-
WASATCH MOUNTAINS SOUTH OF I-80-WASATCH MOUNTAINS/IDAHO PORTION-
WASATCH PLATEAU/BOOK CLIFFS-WEST CENTRAL UTAH-WESTERN UINTA BASIN-
WESTERN UINTA MOUNTAINS-
600 AM MDT WED JUL 7 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE WESTERN TWO THIRDS
OF UTAH AND EXTREME SOUTHEAST IDAHO AND SOUTHWEST WYOMING.

.DAY ONE... TODAY

STRONG SOUTHWEST WINDS AND LOW HUMIDITY IN THE EXTREME WESTERN
VALLEYS WILL RESULT IN DANGEROUS CONDITIONS FOR CONTROLLING
WILDFIRES. MICROBURST WINDS TO 50 MPH ARE ALSO POSSIBLE TODAY NEAR
SHOWERS.

.DAYS TWO THROUGH SEVEN... THURSDAY THROUGH TUESDAY

SOUTHERLY WINDS WILL INCREASE OVER THE WESTERN VALLEYS AND MOUNTAINS
FRIDAY AND CONTINUE TO BE UNSEASONABLY STRONG THROUGH THE WEEKEND
EACH AFTERNOON. THESE WINDS COMBINED WITH LOW HUMIDITY WILL CREATE
DANGEROUS CONDITIONS IF WILDFIRES GET STARTED IN THESE AREAS.