AREA FORECAST DISCUSSION

FXUS66 KLOX 132158
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
200 PM PST TUE FEB 13 2007

.SHORT TERM (TODAY-FRI)...TROF AXIS MOVING EAST OF THE AREA WITH A
POORLY DEFINED CIRCULATION CENTER SOMEWHERE OVER ARIZONA. NORTHWEST
FLOW BEHIND THE LOW ALONG WITH SOME MID LEVEL INSTABILITY ARE THE
FORCING MECHANISMS FOR SOME ISOLATED SHOWERS, MAINLY NEAR THE KERN
COUNTY LINE AS WELL AS THE ERN PORTION OF LA COUNTY. SHOWERS ARE
MOVING QUICKLY, AND THOUGH THERE MAY BE A BRIEF HEAVY SHOWER AMOUNTS
WON`T ADD UP TO MUCH, PERHAPS UP TO A TENTH OF AN INCH. ERN LA
COUNTY SHOWERS WILL TAPER OFF THIS EVENING WHILE THE GRAPEVINE AREA
SHOWERS WILL CONTINUE OFF AND ON THROUGH WED MORNING WITH PERHAPS
ANOTHER INCH OF SNOW ABOVE 5000 FEET.

OVERALL, THE AIRMASS WILL BE DRYING OUT OVER THE NEXT 24 HOURS WITH
NORTHERLY FLOW INCREASING AND MOVING INTO THE LOWER ELEVATIONS.
HIGHS WILL BE A FEW DEGREES WARMER ON WED, THEN SEVERAL DEGREES
WARMER THU AND AGAIN FRI WITH VALLEY AND EVEN SOME COASTAL HIGHS
GETTING INTO THE 80S. IT WILL GET BREEZY BELOW PASSES AND CANYONS,
HOWEVER AT THIS TIME THIS DOESN`T APPEAR TO BE AN ADVISORY LEVEL
WIND EVENT.

.LONG TERM (SAT-TUE)...STILL SOME LINGERING OFFSHORE FLOW ON SAT,
THOUGH ONSHORE TRENDS WILL BRING COOLER WEATHER TO AT LEAST THE
COAST AND VALLEYS. ASIDE FROM THAT, CONFIDENCE REALLY DROPS OFF
THROUGH THE PERIOD. MODELS SEEM TO AGREE THAT A CUTOFF LOW WILL SPIN
OFF A TROF APPROACHING THE WEST COAST EARLY NEXT WEEK. WHERE AND
WHEN THAT WILL HAPPEN IS A MATTER OF MUCH DISAGREEMENT. GFS
ENSEMBLES ARE ALL OVER THE PLACE, AND UNFORTUNATELY WITH A SYSTEM
LIKE THIS EVEN AN ERROR OF 100 MILES COULD MEAN THE DIFFERENCE
BETWEEN RAIN AND SUNNY SKIES. THIS HAS BEEN AN ALL TOO FAMILIAR
PATTERN ALL SEASON AND WE ARE FACED WITH IT ONCE AGAIN. THE
OPERATIONAL GFS KEEPS THE UPPER LOW WELL OFF THE COAST MONDAY, YET
SOMEHOW PUSHES A PRETTY AGRESSIVE FRONT THROUGH WITH SUBSTANTIAL
MOISTURE AND UVV. THIS DOES NOT SEEM LIKELY GIVEN THE POSITION OF
THE LOW. EVEN 12Z TUESDAY THE MAIN LOW CENTER IS STILL A GOOD 500
MILES SOUTHWEST OF LAX. HOWEVER, THE ECMWF IS MUCH FASTER, PUTTING
THE LOW NEAR PT CONCEPTION MONDAY AFTERNOON. CONFIDENCE IS GROWING
THAT SUNDAY WILL BE DRY GIVEN THE TWO MODEL RUNS TODAY, BUT CHANCES
ARE NOT ZERO YET SO WILL LEAVE LOW POPS THERE. AS FOR MONDAY AND
TUESDAY IT`S JUST TOO HARD TO CALL AT THIS POINT. 30 PERCENT POPS IS
ABOUT ALL WE CAN DO FOR NOW AND HOPEFULLY WE`LL GET BETTER ADVANCE
NOTICE ON THIS STORM THAN WE HAVE WITH EARLIER EVENTS. IT SEEMS
LIKELY THAT WE`LL GET SOME PRECIP OUT OF THIS EARLY NEXT WEEK, BUT
PINNING OUR HAT ON ANY ONE 12 HOUR PERIOD IS JUST TOO HARD TO CALL.

&&

.AVIATION...
NORTH OF POINT CONCEPTION...AFTERNOON HEATING WILL PROVIDE ENOUGH
LIFT TO CAUSE CLOUDS TO FORM AND CREATE SCT TO BKN CONDITIONS FOR
THE TAF SITES THIS AFTERNOON. TONIGHT WILL BE CLEAR IN MOST
LOCATIONS...EXCEPT PERHAPS AT KPRB WHERE DENSE FOG MAY FORM
OVERNIGHT.

SOUTH OF POINT CONCEPTION...ASIDE FROM THE MOUNTAINS WHERE CLOUDS
WILL CONTINUE INTO THIS EVENING...MOST OF THE COASTAL AND VALLEY
LOCATIONS WILL CLEAR OUT OVERNIGHT. HOWEVER...SOME OF THE EASTERN
PORTIONS OF THE LOS ANGELES BASIN MAY REMAIN MOSTLY CLOUDY OVERNIGHT
DUE TO TRAPPED MOISTURE AT THE LOWER LEVELS.

KLAX WILL HAVE A STRONGER THAN NORMAL SEA BREEZE THIS AFTERNOON WITH
SOME WIND GUSTS TO NEAR 20 KT...FOLLOWED BY CLEAR SKIES AND LIGHT
WINDS TONIGHT. BY EARLY WEDNESDAY MORNING...NORTHEAST WINDS UP TO 8
KT OR SO ARE POSSIBLE.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXCWFLOX).

&&




PUBLIC...WOFFORD
AVIATION...SWEET