Flash Flooding in Utah, August 19, 2005

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1105 AM MDT FRI AUG 19 2005

.SYNOPSIS...A WEAK UPPER LEVEL DISTURBANCE WILL MOVE INTO SOUTHERN
UTAH TODAY THEN STALL OVER EASTERN UTAH TONIGHT. HIGH PRESSURE WILL
BUILD ACROSS THE REGION OVER THE WEEKEND RESULTING IN A GRADUAL
WARMING TREND.

&&

.DISCUSSION...THE UPPER TROF TRANSLATING EASTWARD INTO CENTRAL
CANADA LEFT BEHIND A WEAK CIRCULATION OVER CA. THIS HAS ACTED AS A
KICKER FOR THE CLOSED CIRCULATION THAT HAD BEEN OFF THE SRN CA COAST
YESTERDAY AND IS NOW LIFTING ENEWD THROUGH NWRN AZ/SWRN UT. THIS
LITTLE LOW HAS SET OFF AN AREA OF CONVECTION THAT IS PRODUCING HEAVY
RAINFALL AND HAIL. MORNING NAM COMPLETELY MISSED IT AND SHOWS NO
PRECIP THIS MORNING. SATELLITE SHOWS THIS LOW WILL SLOWLY LIFT INTO
SERN UT THIS AFTERNOON AND TONIGHT THEN GRADUALLY FILL. IT ALSO
SHOW PRECIPITABLE WATER VALUES HAVE INCREASED CONSIDERABLY OVER
SOUTHERN UTAH THIS MORNING.

THESE FACTORS HAVE PROMPTED THE ISSUANCE OF A FLASH FLOOD WATCH FOR
THIS AREA VALID UNTIL 10 PM. CONVECTION THAT SPREADS INTO ERN UT
LATER TODAY SHOULD HAVE LOWER RAIN AMOUNTS DUE TO DRIER AIRMASS IN
PLACE THERE.

LAST REMAINS OF THE CONVERGENCE ZONE WITH THE DEPARTING HI PLAINS
TROF LAYS ACROSS NRN UT THIS MORNING AND SHOULD BE DISSIPATING
THROUGH THE DAY...ALTHO A FEW CELLS MAY FORM ALONG THIS ZONE EARLY
THIS AFTERNOON.

THE REMNANT OF THE WEAK UPPER LOW APPEARS THAT IT MAY REMAIN A
FACTOR FOR UT WEATHER THROUGH THE WEEKEND AS IT ENDS UP EMBEDDED
WITHIN THE BUILDING HIGH OVER THE WEST...SO WILL CONSIDER BOOSTING
POPS THROUGH THE WEEKEND.

&&

.AVIATION...NONE. SEE SLCTAFSLC.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...FLASH FLOOD WATCH EXTREME SOUTHERN UTAH UNTIL 10PM.
WY...NONE.

&&

WILENSKY

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1205 PM MDT FRI AUG 19 2005

UTZ017>021-201300-
CENTRAL AND SOUTHWEST MOUNTAINS-
GLEN CANYON RECREATION AREA/LAKE POWELL-HENRY MOUNTAINS-
SOUTH CENTRAL UTAH-UTAHS DIXIE AND ZION NATIONAL PARK-
1205 PM MDT FRI AUG 19 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE SOUTHWESTERN THIRD
OF UTAH.

.DAY ONE... TODAY

SCATTERED SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY RAIN AND
HAIL...WILL DEVELOP OVER SOUTHERN UTAH TODAY AND LINGER INTO
TONIGHT. A FLASH FLOOD WATCH IS IN EFFECT FOR A PORTION OF THIS AREA
UNTIL 1000 PM THIS EVENING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED OVER THE
MOUNTAINS THROUGH TUESDAY...WITH ISOLATED STORMS AFFECTING VALLEY
LOCATIONS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1236 PM MDT FRI AUG 19 2005

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1200 PM     FLASH FLOOD      13 W BIG WATER          37.07N 111.90W
08/19/2005                   KANE               UT   PARK/FOREST SRVC

            ROAD TO WHITEHOUSE CAMPGROUND WASHED OUT BY TRIBUTARY TO
            THE PARIA RIVER. LOCATED OFF OF ROUTE 89.

&&

ATARDY