Flash Flood Warning 33, NWS Las Vegas, NV

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE LAS VEGAS NV
325 PM PDT WED AUG 23 2006

.SYNOPSIS...DRY WESTERLY FLOW ALOFT WILL SPREAD OVER THE REGION
THURSDAY AND FRIDAY. THERE IS A POSSIBILITY THAT LOW LEVEL MOISTURE
FROM THE GULF OF CALIFORNIA COULD SURGE UP THE LOWER COLORADO RIVER
VALLEY EARLY THURSDAY FOR A SLIGHT CHANCE OF THUNDERSTORMS REMAINING
OVER SOUTHEAST CALIFORNIA AND SOUTHERN NEVADA. A DRYING TREND WILL
THEN DOMINATE GOING INTO THE WEEKEND AND KEEP THUNDERSTORMS CONFINED
TO ARIZONA AS A TROUGH OF LOW PRESSURE MOVES ACROSS THE GREAT BASIN.
&&

.SHORT TERM...SATELLITE IMAGERY SHOWS A DEFINITIVE DRY AND STABLE
AREA FROM CENTRAL CLARK COUNTY AND POINTS NORTHWEST. THE NAM AND GFS
INDICATE A 500 MB DEFORMATION ZONE ACROSS SOUTHEAST CALIFORNIA UP
THROUGH SOUTHERN CLARK AND MOHAVE COUNTIES AND THAT HAS BEEN THE
FAVORED AREA FOR THUNDERSTORM DEVELOPMENT AND SHOULD BE THROUGH THE
EVENING. WILL KEEP THE FLASH FLOOD WATCH IN EFFECT FOR THE MORONGO
BASIN OF CALIFORNIA THROUGH 8 PM THIS EVENING AS THUNDERSTORMS LURK
OVER THE NEARBY MOUNTAINS. THUNDERSTORMS MOVING OFF THE ARIZONA RIM
COUNTRY SHOULD AGAIN BECOME FAIRLY WELL ORGANIZED AS THEY PROPAGATE
SOUTHWEST ACROSS SOUTHERN MOHAVE COUNTY THIS EVENING. THE NAM AND
GFS CONTINUE TO SHOW A STRONG DRYING TREND THURSDAY BUT THERE IS A
POSSIBILITY OF A LOW LEVEL GULF SURGE INITIATED BY HURRICANE ILEANA
WHICH WAS NOT FAR FROM THE MOUTH OF THE GULF OF CALIFORNIA. IT WILL
BE DIFFICULT TO DETERMINE IF ONE IS UNDERWAY UNTIL EARLY THURSDAY
DUE TO LACK OF GOOD DATA ALONG THE GULF. KEPT A SLIGHT CHANCE OF
THUNDERSTORMS OVER SOUTHERN NEVADA/SOUTHEAST CALIFORNIA THURSDAY
ACCORDINGLY. IF LOW LEVEL MOISTURE DOES MAKE IT INTO THE
REGION...DRIER AND COOLER WESTERLY FLOW ALOFT...FAVORABLE JET
INTERACTION AND GOOD VERTICAL SHEER WOULD PROVIDE AN ENVIRONMENT FOR
MORE ORGANIZED SEVERE THUNDERSTORMS. THE DRY WESTERLY FLOW IS
FORECAST TO PERSIST FRIDAY AND MAY WIN OUT IF LOW LEVEL MOISTURE
DOES NOT GET TOO DEEPLY ENTRENCHED. THIS IS INDICATED BY POPS
CONFINED MAINLY TO MOHAVE COUNTY FRIDAY.

.LONG TERM...GFS STILL AGGRESSIVE IN MOVING MOISTURE OUT THIS
WEEKEND...WHICH EXPERIENCE SAYS IS TOO HOPEFUL. GFS SHOWS SOMEWHAT
DRY NORTHWEST FLOW WITH AN UPPER LEVEL HIGH DEVELOPING TO THE WEST
AND MOVING OVER THE AREA SUNDAY AND INTO EARLY NEXT WEEK. MOISTURE
IS DEPICTED AS BEING SUPPRESSED TO THE SOUTH. HAVE KEPT EXISTING
POPS IN THE EAST PART OF MOHAVE COUNTY THROUGH TUESDAY. AT THE END
OF THE EXTENDED BOTH GFS AND EURO SHOW A STRONG TROUGH/FRONT
APPROACHING THE WEST COAST WEDNESDAY. THERMAL PACKING LOOKS PRETTY
IMPRESSIVE FOR LATE SUMMER. IN ANY EVENT SOUTHWEST FLOW SHOULD BE
ENOUGH TO MOVE THE MOISTURE OUT FINALLY.
&&

.AVIATION...THUNDERSTORMS WILL PERSIST IN THE VICINITY OF THE PEACH
SPRINGS AND MORMON MESA CORRIDORS. THESE STORMS WILL HAVE THE
POTENTIAL FOR STRONG GUSTY WINDS AND HEAVY RAIN. TOMORROW WILL SEE
ANOTHER OUTBREAK OF THUNDERSTORMS IN THE SAME AREAS AND THE
POSSIBILITY FOR OUTFLOW BOUNDARIES IN THE LAS VEGAS VALLEY IN THE
AFTERNOON AS WELL. TAFS AND TWEBS ADEQUATELY DESCRIBE EXPECTED
WEATHER CONDITIONS FOR AREA TERMINALS. SEE TAFS FOR KLAS... KVGT...
KDRA... KBIH... KDAG... KEED... FOR DETAILS. &&

.VEF WATCHES/WARNINGS/ADVISORIES...
.NV...NONE.
.AZ...NONE.
.CA...FLASH FLOOD WATCH IN EFFECT UNTIL 8 PM PDT FOR CA ZONE 25.

ADAIR/JACQUES

HTTP://WEATHER.GOV/LASVEGAS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LAS VEGAS NV
1004 AM PDT WED AUG 23 2006

AZZ001>003-036-CAZ522>527-NVZ015>022-240700-
NORTHWEST PLATEAU-LOWER COLORADO RIVER VALLEY-NORTHWEST DESERTS-
LAKE MEAD NATIONAL RECREATION AREA-DEATH VALLEY NATIONAL PARK-
WESTERN MOJAVE DESERT-EASTERN MOJAVE DESERT-MORONGO BASIN-
CADIZ BASIN-SAN BERNARDINO COUNTY-UPPER COLORADO RIVER VALLEY-
LINCOLN COUNTY-NORTHEAST CLARK COUNTY-
WESTERN CLARK AND SOUTHERN NYE COUNTY-SHEEP RANGE-
SPRING MOUNTAINS-LAS VEGAS VALLEY-SOUTHERN CLARK COUNTY-
1004 AM PDT WED AUG 23 2006 /1004 AM MST WED AUG 23 2006/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST
ARIZONA...CALIFORNIA AND SOUTHERN NEVADA.

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS THE SOUTHERN SAN
BERNARDINO COUNTY DESERTS...SOUTHERN NEVADA AND NORTHWEST ARIZONA
THIS AFTERNOON AND CONTINUE DURING THE EVENING. THUNDERSTORMS WILL
BE SLOWING MOVING AND MAY PRODUCE SOME LOCAL FLASH FLOODING. A
FLASH FLOOD WATCH HAS BEEN ISSUED FOR THE MORONGO VALLEY OF
CALIFORNIA FOR POTENTIAL FLASH FLOODING ASSOCIATED WITH RECENT
BURN AREAS. IN ADDITION...STRONG WIND GUSTS OVER 50 MPH AND SMALL
HAIL WILL BE POSSIBLE WITH SOME ISOLATED THUNDERSTORMS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

DRIER MID LEVEL AIR IS FORECAST TO PUSH IN FROM THE WEST THURSDAY
FOR DIMINISHING THUNDERSTORM COVERAGE WITH STORMS MAINLY CONFINED
TO MOHAVE COUNTY GOING INTO THE WEEKEND.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY. HOWEVER...WEATHER
SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS
ACCORDING TO STANDARD OPERATING PROCEDURES.

JGA