FXUS66 KLOX 251808
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1000 AM PST FRI DEC 25 2009

.SYNOPSIS... 
A WEAK UPPER LEVEL RIDGE WILL CONTINUE TO KEEP CONDITIONS DRY ACROSS 
THE AREA THROUGH SATURDAY EVENING. A SERIES OF WEAK STORM SYSTEMS 
MOVING THROUGH THE EASTERN PACIFIC WILL BRING A SLIGHT CHANCE OF 
RAIN TO PARTS OF THE REGION SATURDAY NIGHT THROUGH MONDAY...THEN DRY 
AND SEASONABLY COOL WEATHER IS EXPECTED TUESDAY THROUGH THURSDAY.

&&

.SHORT TERM (TODAY-SUN)...FROST ADVISORIES EXPIRED LAST HOUR AS 
TEMPS HAVE RISEN ABOVE FREEZING. HIGH TEMPS TODAY SHOULD BE VERY 
SIMILAR TO YESTERDAY SANS NEAR IMMEDIATE COAST WHERE SEA BREEZE 
SHOULD RETURN THIS AFTERNOON WITH GRADIENTS TRENDING ONSHORE. 
SATELLITE PIXS SHOW PATCHY STRATUS FORMING IN THE BIGHT AND OFFSHORE 
THIS MORNING OFFERING UP A CLUE TO WHAT WILL HAPPEN TONITE. I AM 
INCLINED TO INTRODUCE PATCHY MARINE LAYER CLOUDS IN COASTAL AREAS 
OVERNIGHT AND 975MB MOISTURE GUIDANCE SUPPORTS THIS IDEA. NO OTHER 
CHANGES NEEDED AT THIS TIME IN THE SHORT-TERM.  12Z GUIDANCE IS EVEN 
DRIER WITH UPCOMING WEAK SYSTEM TO PASS THROUGH THE REGION SAT 
NITE/SUNDAY. WILL CONSIDER REMOVING MENTION OF POPS SOUTH OF PT. 
CONCEPTION FOR THIS AFTERNOON PACKAGE ONCE COORDINATED WITH 
SURROUNDING OFFICES. 

.LONG TERM (SUN NIGHT-THU)...ALL MODELS HAVE CONVERGED ON A SOLUTION 
REGARDING THE TRACK OF AN UPPER LOW TO THE S AND W OF THE FCST AREA. 
12Z GUIDANCE NOW KEEPS ALL RAIN OFF THE COAST. WILL LIKELY TRIM POPS 
ACCORDINGLY AFTER COORDINATION. A NWLY FLOW PATTERN ALOFT WILL SET 
UP OVER THE FCST AREA TUE THRU THU...WITH DRY WEATHER EXPECTED...AND 
TEMPS SLIGHTLY BELOW NORMAL. 

&&

.AVIATION...25/1800Z.

MID/UPPER LEVEL TROUGH OF LOW PRESSURE UPSTREAM WILL APPROACH THE 
AREA. MODERATE UPPER LEVEL WEST WINDS WILL BECOME STRONG SOUTHWEST 
WHILE MID LEVEL LIGHT NORTHEAST WINDS BECOME LIGHT SOUTHWEST AFTER 
26/18Z. WEAK OFFSHORE PRESSURE GRADIENT WILL BECOME WEAK ONSHORE 
EARLY AND PERSIST THROUGH THE REMAINDER OF THE PERIOD. 

KLAX...THERE IS A CHANCE CIGS AROUND 010 WILL DEVELOP AFTER 26/06Z 
AND PERSIST THROUGH 26/17Z...OTHERWISE CIGS 250 AFTER 26/12Z 
THROUGH THE REMAINDER OF THE PERIOD.  

KBUR...VIRTUALLY CERTAIN CURRENT SKY/VSBY CONDITIONS WILL PREVAIL 
THROUGH 26/12Z THEN CIGS 250 THROUGH THE REMAINDER OF THE PERIOD.

VIRTUALLY CERTAIN - 95-100%
VERY LIKELY       - 80-95%
LIKELY            - 60-80%
CHANCE            - 30-60%
VERY UNLIKELY     - 20% OR LESS
 

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
NONE

&&

$$

PUBLIC...TRM
AVIATION...30
SYNOPSIS...JS

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