AREA FORECAST DISCUSSION

AREA FORECAST DISCUSSION


FXUS66 KLOX 262212
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
210 PM PST SUN FEB 26 2006

.SHORT TERM (TODAY-WED)...VERY FEW CHANGES MADE TO THE FORECAST.
TIMING STILL LOOKS ON TRACK, THOUGH IT MAY TAKE A LITTLE LONGER THAN
EXPECTED FOR WIDESPREAD RAIN TO DEVELOP IN LA COUNTY. WOULD NOT BE
SURPRISED IF THIS DID NOT OCCUR UNTIL VERY LATE IN THE AFTERNOON OR
NEAR RUSH HOUR. EVERYWHERE ELSE THOUGH RAIN SHOULD START UP TONIGHT
OR MONDAY MORNING. VBG RADAR SHOWING SOME WEAK RETURNS OVER SLO
COUNTY BUT SO FAR NOTHING IN THE GAGES AND PRB HAS ONLY REPORTED A
TRACE SO FAR. IT MAY BE LIKE THIS FOR QUITE AWHILE AS THE AIRMASS
HAS A LOT OF MOISTENING UP TO DO BASED ON THE 12Z VBG SOUNDING AND
CURRENT SURFACE DEWPOINTS WHICH ARE STILL IN THE 20S AND 30S. SO
PROBABLY A LOT OF VIRGA, AND ANY SHOWERS WILL MAINLY BE ON THE LIGHT
SIDE TONIGHT UP IN SLO/SBA COUNTIES WITH MAYBE A SPRINKLE OR TWO
DOWN IN LA/VTU COUNTIES OVERNIGHT.

THE BULK OF THIS EVENT WILL TAKE PLACE MONDAY AFTERNOON INTO EARLY
TUESDAY MORNING. THIS TIME PERIOD WILL HAVE THE HIGHEST POTENTIAL
FOR FLOODING ISSUES, MAINLY NEAR THE BURN AREAS. CURRENT FLASH FLOOD
WATCH LOOKS GOOD, THOUGH AGAIN I THINK THE ONLY REAL AREAS OF
CONCERN WILL BE THE BURN AREAS AS THE RIVER AND STREAMS ARE PRETTY
DRY. THRESHOLDS FOR BURN AREA MUD AND DEBRIS FLOWS ARE VERY LOW,
ESPECIALLY FOR BURNS THAT HAVE TAKEN PLACE IN THE LAST 6-12 MONTHS
AND THIS STORM COULD EASILY PRODUCE RAINFALL RATES IN EXCESS OF
THOSE THRESHOLDS. RESIDENTS NEAR BURN AREAS SHOULD BE PREPARING FOR
MAJOR MUD AND DEBRIS FLOWS WITH THIS STORM. AND OF COURSE THERE WILL
BE THE USUAL LITTANY OF FLOOD ADVISORIES FOR NUISANCE FLOODING OVER
ROADS AND HIGHWAYS.

THUNDERSTORMS DON`T APPEAR TO BE A BIG ISSUE WITH THIS EVENT, THOUGH
THERE COULD BE AN ISOLATED THUNDERSTORM OR TWO WITH THE MAIN FRONTAL
BAND. TEMPERATURES ALOFT NEVER GET THAT COLD AND AS A RESULT THE
AIRMASS NEVER REALLY DESTABILIZES SIGNIFICANTLY. WILL KEEP A SLIGHT
CHANCE IN THOUGH JUST IN CASE WE GET ONE OR TWO WITH THE MAIN FRONT,
MAINLY LATE MONDAY AND EARLY TUESDAY.

SNOW LEVELS WILL BE VERY HIGH WITH THIS EVENT. WARM AIR ADVECTION
HAS BEEN QUITE IMPRESSIVE TODAY WITH SURFACE TEMPS INTO THE 70S AT
LOWER ELEVATIONS AND MID 60S IN THE MOUNTAINS. VERY HIGH ELEVATIONS,
9000 FEET AND ABOVE COULD SEE SOME DECENT SNOW ACCUMULATIONS BUT WE
GENERALLY DON`T ISSUE WARNINGS OR ADVISORIES FOR SNOW ABOVE 7500
FEET SO NO WINTER PRODUCTS ARE EXPECTED TO BE ISSUED FOR THIS EVENT.
SNOW LEVELS COULD LOWER TO AROUND 6000-7000 FEET BY TUESDAY MORNING
BUT THE BULK OF THE STORM WILL BE THROUGH THE AREA BY THAT TIME.

AS FAR AS THE WINDS GO, LATEST MODELS DON`T SHOW QUITE AS MUCH
SOUTHERLY GRADIENT BETWEEN LAX AND SFO AND I THINK WIND ADVISORIES
WILL SUFFICE, AT LEAST FOR THE CENTRAL COAST MONDAY INTO MONDAY
NIGHT. WILL LEAVE THE HIGH WIND WATCH UP FOR THE LA/VTU MOUNTAINS
MONDAY NIGHT INTO TUESDAY.

RAIN SHOULD BE TAPERING OFF TUESDAY, BUT THE NAM STILL SHOWS
CONSIDERABLE LOW LVL MOISTURE AND SOUTH-SOUTHWEST FLOW. AND WITH THE
TROF AXIS JUST PASSING THROUGH THE AREA TUESDAY AFTERNOON SHOWER
CHANCES WILL CONTINUE AT LEAST THROUGH THE EVENING HOURS.

AT THIS TIME WED LOOKS DRY WITH SLIGHTLY WARMER TEMPS.

.LONG TERM (WED NT-SUN)...12Z GFS SHOWS A MORE PROGRESSIVE PATTERN
FOR THE LATTER HALF OF THE WEEK WITH THE NEXT STORM NOW ARRIVING
ALONG THE CENTRAL COAST WED NIGHT AND INTO THE LA AREA THURS. WENT
AHEAD AND BUMPED UP POPS ALL AREAS THURSDAY, THOUGH RAINFALL AMOUNTS
WILL BE CONSIDERABLY LOWER THAN WITH THIS FIRST STORM. TROF AXIS
WILL MOVE THROUGH FRIDAY MORNING WITH LINGERING SHOWERS EARLY ON.
THEN DRIER CONDITIONS EXPECTED FRIDAY NIGHT INTO SATURDAY. THE REST
OF THE WEEKEND LOOKS DRY.

&&

.AVIATION...A WARM FRONT WAS MOVING NORTHEAST SPREADING SCATTERED
LIGHT PRECIPITATION OVER THE NORTHERN HALF OF THE AREA OVERNIGHT. A
COLD FRONT WILL APPROACH THE AREA MONDAY AND EVENTUALLY MOVE OVER
THE AREA MONDAY NIGHT. MODERATE UPPER LEVEL SOUTHWEST FLOW WILL
BECOME STRONG OVERNIGHT. FREEZING LEVEL WAS AROUND 11KFT THIS
MORNING AND WILL ASCEND A FEW HUNDRED FEET OVERNIGHT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH (SEE LAXNPWLOX).
FLOOD WATCH (SEE LAXFFALOX).
WIND ADVISORY (SEE LAXNPWLOX).
GALE WARNING (SEE LAXCWFLOX).
SMALL CRAFT ADVISORY (SEE LAXCWFLOX).
SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX).

&&





PUBLIC...WOFFORD
AVIATION...FORWOOD