FXUS66 KLOX 021127
AFDLOX
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
327 AM PST WED DEC 2 2009
...UPDATED AVIATION SECTION...
.SYNOPSIS...
COOL WITH A DEEP MARINE LAYER COVERING THE COASTS AND VALLEYS TODAY.
WEAK OFFSHORE FLOW WILL MAKE FRIDAY THE SUNNIEST AND WARMEST DAY OF
THE NEXT SEVEN. COOLER WITH INCREASING CLOUDS OVER THE WEEKEND.
CLOUDY AND COOL WITH A CHANCE OF RAIN EARLY NEXT WEEK.
&&
.SHORT TERM (TODAY-FRI)...
MARINE LAYER IS SURPRISINGLY AT 3200 FEET THIS MORNING AND AS A
RESULT LOW CLOUDS HAVE PUSHED INTO ALL VLYS INCLUDING THE SANTA
CLARITA. NAM MOISTURE FIELDS KEEP VERY HIGH RH VALUES OVER THE
BEACHES AND IT LOOKS LIKE THE LOW CLOUDS WILL ONLY CLEAR TO NEAR THE
SHORE. WITH ALL THE LIFT THERE HAVE BEEN A FEW DRIZZLE REPORTS AND
ADDED SOME PATCHY DRIZZLE TO THE FORECAST IT WILL BE MOST LIKELY
NEAR THE FOOTHILLS. TODAY WILL BE COOL WITH MOST COASTAL AND VLY
LOCATIONS ONLY REACHING THE MID 60S. THURSDAY DOES NOT LOOK MUCH
BETTER EXCEPT THAT OFFSHORE TRENDS SHOULD KEEP THE CLOUDS OUT OF THE
SANTA CLARITA VLY AND ALLOW FOR TOTAL CLEARING IN THE AFTERNOON.
TEMPS WILL INCH UP A FEW DEGREES. ASIDE FROM THE MARINE LAYER SOME
MID AND HIGH LEVEL CLOUDS WILL DRIFT OVER THE AREA.
HIGH PRESSURE BRIEFLY NOSES INTO NV THURSDAY NIGHT AND FRIDAY. THIS
SHOULD BLOW THE MARINE LAYER OUT...ALTHOUGH THE NAM IS WORRISOMELY
TRENDING TO A LESS THAN CLEAR FORECAST FOR L.A. COUNTY. WITH MOSTLY
SUNNY 575 DM HGTS OVERHEAD AND THE OFFSHORE FLOW AT THE SURFACE THIS
SHOULD BE THE WARMEST DAY OF THE NEXT 7.
.LONG TERM (SAT-TUE)...
COOLER SATURDAY AS FRIDAYS WEAK RIDGE BREAKS DOWN AND THE OFFSHORE
FLOW FLIPS AROUND TO ONSHORE. MID AND HIGH LEVEL MOISTURE WILL
CREATE PARTLY CLOUDY SKIES.
EC...GFS AND GEM MDLS ARE ALL IN AGREEMENT THAT STARTING SUNDAY
THERE WILL BE A MAJOR PATTERN SHIFT AND THE DOOR WILL OPEN UP FOR
RAIN. THERE IS LITTLE AGREEMENT ON THE EXACT TIMING AND INTENSITY OF
ANY GIVEN STORM.
EVERYTHING STARTS LATE SATURDAY AS A LOW PINCHES OFF FROM A TROF
SWEEPING THROUGH MONTANA. THIS LOW THEN RETROGRADES OVER WASHINGTON
AND OREGON ALL THE MDLS HANDLE THE RETROGRADE DIFFERENTLY AND THIS
IS WHAT IS CAUSING THE UNCERTAINTY. AT THE MOMENT IT LOOKS LIKE
MONDAY HAS THE BEST CHANCE OF RAIN WITH ALL THE MDLS SHOWING
SOMETHING GOING ON. BOTH GEM AND GFS FORECAST A RAIN...NO
RAIN...RAIN FORECAST WHILE THE EC KEEPS THE RAIN GOING NON STOP.
BOTH THE GFS AND THE GEM HAVE BEEN FLIP FLOPPING SOME ON THEIR
FORECAST FROM RUN TO RUN WHILE THE EC HAS HAD REMARKABLE
CONSISTENCY. HATE TO SOUND LIKE A BROKEN RECORD (SKIPPING CD?) BUT
FOR NOW WILL BROAD BRUSH SLGT CHC TO CHC POPS THROUGH THE PERIOD AND
HOPE FOR BETTER MDL CONSENSUS LATER TODAY. RIGHT NOW IT IS HARD TO
IMAGINE IT NOT RAINING SOMETIME DURING THE MONDAY THROUGH WEDNESDAY
PERIOD...BUT EXACTLY WHEN IS PROBLEM.
&&
.AVIATION...02/1127Z.
MVFR CONDITIONS ARE EXPECTED AT ALL COASTAL AND VALLEY TERMINALS
THROUGH AT LEAST 18Z THIS MORNING...WITH LOCAL CEILINGS LIFTING INTO
THE VFR CATEGORY. CLEARING WILL LIKELY OCCUR AT SOME TERMINALS
BETWEEN 18Z AND 22Z...WITH THE COASTAL AREAS LIKELY STRUGGLING TO
CLEAR UNTIL BETWEEN 22Z AND 00Z THIS AFTERNOON. AT KPRB...VFR
CONDITIONS SHOULD PERSIST THROUGH 04Z THIS EVENING...WITH A CHANCE
OF LIFR TO IFR CONDITIONS BETWEEN 12Z AND 16Z.
KLAX...VFR CONDITIONS WITH CEILINGS BELOW 6000 FEET ARE EXPECTED
THROUGH AT LEAST 01Z THIS AFTERNOON...WITH A 30 PERCENT CHANCE THAT
CEILINGS COULD SCATTER OUT BETWEEN 22Z AND 01Z. AFTER 01Z...MVFR
CONDITIONS SHOULD BECOME PREDOMINANT...WITH A 20 PERCENT CHANCE OF
CONDITIONS DROPPING TO IFR AFTER 08Z TONIGHT.
KBUR...MVFR CONDITIONS WILL LIKELY PERSIST THROUGH 20Z...WITH A 30
PERCENT CHANCE THAT CEILINGS COULD LIFT INTO THE VFR CATEGORY.
CEILINGS SHOULD SCATTER OUT BETWEEN 20Z AND 22Z THIS AFTERNOON...BUT
THERE IS A 20 PERCENT CHANCE THAT CEILINGS NO CLEARING COULD OCCUR.
AFTER 03Z...MVFR CONDITIONS SHOULD BECOME PREDOMINANT...WITH A 20
PERCENT CHANCE OF CONDITIONS DROPPING TO IFR AFTER 08Z TONIGHT.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
PUBLIC...RORKE
AVIATION...HALL
SYNOPSIS...ASR
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