Flash Flood and Hail in Utah, September 29, 2004

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
941 AM MDT WED SEP 29 2004

.SYNOPSIS...AN UPPER LOW WILL DRIFT SLOWLY EAST ACROSS SOUTHERN
NEVADA AND UTAH THROUGH TOMORROW BRINGING PRECIPITATION TO THE AREA.
HIGH PRESSURE ALOFT WILL RETURN A DRIER AIRMASS FOR THE WEEKEND.

&&

.DISCUSSION...BROAD UPPER TROUGH OVER NEVADA AND UTAH CONTINUES TO
PULL MOISTURE NORTHWARD ACROSS UTAH. MESSY PATTERN WITH AT LEAST
THREE VORTICITY LOBES WRAPPING AROUND THIS LOW AND CAUSING NUMEROUS
SHOWERS AND THUNDERSTORMS ACROSS THE STATE. DRY SLOT OVER WEST
CENTRAL UTAH WILL FILL IN THIS AFTERNOON AS DAYTIME HEATING INDUCES
CONVECTION. 06Z GFS INDICATES AN AREA OF -4 LIS OVER SOUTHERN UTAH
AT NOON TODAY SHIFTING EASTWARD THROUGH THIS AFTERNOON. SHOWERS AND
THUNDERSTORMS ALREADY OCCURRING OVER THAT AREA AND ARE EXPECTED TO
CONTINUE THROUGH THE DAY. PW VALUES OF .5 TO .75 INCH PROGGED FOR
THE STATE THROUGH THURSDAY. GOES PW HINTS THAT SOME VALUES OF .75 ARE
ALREADY OVER THE WEST AND SOUTHWEST PORTION OF THE STATE. EVEN THOUGH
MOST OF THE AREA COVERED WITH CLOUDS...HAVE TO ASSUME MODELS HAVE A
PRETTY GOOD HAND ON SITUATION FOR THE REMAINDER OF THE STATE.
THURSDAY LOOKS TO BE ANOTHER ACTIVE DAY ALTHOUGH WITH A SLOWLY
DECREASING TREND. ONLY EXPECT LINGERING MOISTURE INTO FRIDAY AND
SATURDAY AND MAINLY OVER THE MOUNTAINS AND EASTERN PORTIONS OF THE
AREA. NEAR NORMAL TEMPERATURES TODAY AND THURSDAY WITH A WARMING
TREND INTO FRIDAY AND SATURDAY. PREVIOUS PACKAGE LOADED WITH WEATHER
AND RIGHTLY SO. NO UPDATES NEEDED.

NO SIGNIFICANT WINDS ARE EXPECTED OUTSIDE OF CONVECTION WHERE GUSTY
WINDS ARE POSSIBLE...ALTHOUGH WITH THE ABUNDANCE OF MOISTURE AND THE
POSSIBILITY OF HEAVY RAINS...EXPECT WINDS TO BE OF MINIMAL IMPORTANCE
AT THIS TIME. GRAND JUNCTION HAS ISSUED A FLASH FLOOD WATCH FOR
SOUTHWEST COLORADO AND EXTREME SOUTHEAST UTAH THROUGH 600 PM THIS
EVENING. EXPECT THE THREAT OF FLASH FLOODING TO REMAIN TO THE
SOUTHEAST AND NOT MEANDER WESTWARD INTO THE SALT LAKE CITY CWA.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...

UT...NONE.
WY...NONE.
ID...NONE.

&&

YOUNG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
530 AM MDT WED SEP 29 2004

IDZ024-025-UTZ001>021-WYZ021-301300-
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-
530 AM MDT WED SEP 29 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE HIGHER TERRAIN OF
UTAH...EXTREME SOUTHEAST IDAHO AND SOUTHWEST WYOMING.

.DAY ONE... TODAY

AN APPROACHING UPPER LEVEL LOW WILL CONTINUE SHOWERS AND
THUNDERSTORMS TODAY. SOME OF THESE STORMS WILL PRODUCE HEAVY RAIN
AND GUSTY WINDS. CHECK THE LATEST FORECASTS BEFORE BEGINNING OUTDOOR
ACTIVITIES. NORMALLY DRY OR LOW FLOWING CREEKS IN SOUTHERN
UTAH COULD HAVE HIGH WATER LEVELS.

.DAYS TWO THROUGH SEVEN... THURSDAY THROUGH TUESDAY

MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED ON THURSDAY.
SOME OF THESE STORMS WILL PRODUCE HEAVY RAIN. SOME THUNDERSTORMS ARE
POSSIBLE FRIDAY AND SATURDAY...MAINLY EASTERN AND SOUTHERN UTAH...BUT
A DRYING TREND WILL BEGIN ACROSS THE NORTH. NEXT CHANCE OF
PRECIPITATION IS MONDAY AND TUESDAY.

AOT