Flash Flood in Utah, August 8, 2005

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1025 AM MDT MON AUG 8 2005

.SYNOPSIS...HIGH PRESSURE ALOFT WILL REMAIN ACROSS THE GREAT BASIN
THROUGH THE MIDDLE OF THE COMING WEEK. INSTABILITY AND MOISTURE WILL
INCREASE OVER UTAH FROM THE SOUTH AND WEST TODAY AS A DISTURBANCE
MOVES THROUGH THE REGION.

&&

.DISCUSSION...A MOIST AND UNSTABLE AIRMASS WILL REMAIN OVER SOUTHERN
UTAH TODAY. QUITE A BIT OF MID AND HIGH LEVEL CLOUD COVER OVER THE
AREA EARLY THIS MORNING...BUT THUNDERSTORMS SHOULD HAVE NO PROBLEMS
DEVELOPING AS THESE CLOUDS CONTINUE TO DISSIPATE. GOES-DERIVED PW
VALUES OVER AN INCH THIS MORNING THROUGHOUT EXTREME SOUTHERN
UTAH...SO CONVECTION COULD PRODUCE LOCALLY HEAVY
RAINFALL...ESPECIALLY WITH THE FLOW BEING RELATIVELY LIGHT IN THAT
AREA.

OVER THE NORTH...A SHORTWAVE TROUGH WILL MOVE ACROSS IDAHO TODAY.
THIS WILL GIVE THE NORTHERN PORTIONS A LITTLE BOOST FOR CONVECTION.
THE NORTH HAS MOISTENED UP A BIT FROM YESTERDAY...WITH PW VALUES
AROUND AN INCH NEAR THE GSL AND WEST CENTRAL UTAH. MODELS SUGGEST
THAT THE TROUGH AXIS WILL MOVE ACROSS THE AREA BY LATE
AFTERNOON/EARLY EVENING. THE FLOW TURNS NORTHWESTERLY BEHIND THE
TROUGH WITH THE AIRMASS BECOMING DRIER AND MORE STABLE. THIS WILL
LIMIT CONVECTION MAINLY TO THE SOUTHERN PORTIONS TOMORROW. ON
WEDNESDAY...ANOTHER DISTURBANCE ROTATES INTO NORTHERN UTAH. MODELS
SUGGEST THAT A JET STREAK WILL DEVELOP OVER NORTHERN UTAH...UP TO
50KTS AT 300MB ON THE GFS...BUT A BIT WEAKER ON THE NAM. WITH PW
INCREASING OVER NORTHERN UTAH AGAIN ON WEDNESDAY...WOULD EXPECT IT
TO BE A FAIRLY ACTIVE DAY.

A MODERATE WESTERLY FLOW WILL DEVELOP OVER NORTHERN UTAH FOR THE
LATTER PART OF THE WEEK. DRIER AIR WILL MOVE IN AS A RESULT.
MOISTURE MAY STILL LINGER IN THE EXTREME SOUTHEASTERN PORTIONS
HOWEVER.

CURRENT PACKAGE LOOKS FINE. NO UPDATES PLANNED THIS MORNING.

&&

.FIRE WEATHER...ALTHOUGH THUNDERSTORMS OVER NORTHWEST UTAH THIS
AFTERNOON WILL NOT BE ALL THAT DRY...FINE FUELS ARE AT CRITICAL
LEVELS SO ANY LIGHTNING AWAY FROM THE SMALL RAIN SHAFTS COULD BRING
FIRE STARTS. SO WILL KEEP FIRE WEATHER WATCH GOING AND WILL UPGRADE
TO WARNING THIS AFTERNOON.

&&

.AVIATION...NONE. SEE SLCTAFSLC.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...FIRE WEATHER WATCH FOR DRY LIGHTNING MONDAY AFTERNOON AND
     EVENING FIRE ZONES 420 AND 434.
WY...NONE.

&&

PUBLIC...CHENG
FIRE...WILENSKY

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
700 AM MDT MON AUG 8 2005

UTZ001>021-WYZ021-091300-
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 PLATEAU/BOOK CLIFFS-
WEST CENTRAL UTAH-WESTERN UINTA BASIN-WESTERN UINTA MOUNTAINS-
700 AM MDT MON AUG 8 2005

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

.DAY ONE... TODAY

SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS UTAH TODAY.
OVER THE WEST-CENTRAL AND NORTHWEST UTAH DESERTS THESE STORMS WILL
PRODUCE LITTLE RAINFALL AND STRONG MICROBURST WINDS. A FIRE WEATHER
WATCH HAS BEEN ISSUED FOR THE POTENTIAL OF DRY LIGHTNING COMBINED
WITH THE LOCAL STRONG WINDS. IN FAR SOUTHERN UTAH...HEAVY RAIN IS
POSSIBLE NEAR SLOW MOVING THUNDERSTORMS.

.DAYS TWO THROUGH SEVEN... TUESDAY THROUGH SUNDAY

SCATTERED SHOWERS AND THUNDERSTORMS WILL REMAIN ACROSS MOST OF UTAH
THROUGH THE WORK WEEK.

SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.