000
FXUS66 KLOX 171208
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
440 AM PDT WED SEP 17 2008

.SHORT TERM...
UPDATE...MARINE LAYER INTRUSION IS MUCH STRONGER THAN EARLIER
THOUGHT AND ISSUED AN UPDATE TO COOL THINGS OFF.

MARINE LAYER HAS RISEN TO 1200 TO 1300 FEET AND GRADIENTS ARE ABOUT
3 MB ONSHORE  BOTH TO THE NORTH AND TO THE EAST WHICH IS CLOSE TO A
4 MB ONSHORE TREND. THIS WILL NOT COOL THE VLYS MUCH...WHICH IS
UNUSUAL...SINCE THERE WILL BE MUCH MORE SUNSHINE THAN YDY. THE
CENTRAL COAST WILL BE VERY SIMILAR TO YDY WITH SUNNY SKIES AFTER
MORNING LOW CLOUDS. TEMPS ON THE COAST WILL BE SIMILAR TO YDY WHILE
THE SALINAS VLY WILL DROP A FEW DEGREES WITH A DEEPER MARINE LAYER.
STILL ENOUGH MID LEVEL MOISTURE AND INSTABILITY OVER THE MTNS TO
WARRANT A SLGT CHC OF AFTERNOON AND EVENING TSTMS BUT IF THEY DO
FORM THEY SHOULD BE MORE ISOLATED THAN YDY DUE TO THE DECREASE IN
MOISTURE.

THE MARINE LAYER SHOULD REMAIN ABOUT THE SAME WEDNESDAY NIGHT AND
THURSDAY MORNING. ALSO WITH LITTLE CHANGE IN THE HGTS THE GRADIENTS
AND THE MARINE LAYER THURSDAY SHOULD BE VERY SIMILAR TO TODAY EXCEPT
THAT THE MID LEVELS WILL BE VERY DRY AND THERE WILL BE NO CHC OF
TSTM FORMATION.

A NEGATIVE TILT UPPER LOW MOVES INTO NRN CA FRIDAY. THIS SHOULD LIFT
THE MARINE LAYER INTO ALL COASTS AND VLYS AND COOL THINGS DOWN. THE
NAM HOWEVER THROWS A LITTLE CURVE INTO THE MIX AND FORECASTS ZERO
MARINE LAYER FOR AREAS SOUTH OF POINT CONCEPTION. THERE IS LITTLE TO
INDICATE WHY SUCH A CLEARING SHOULD TAKE PLACE OTHER THAN A WEAKER
EDDY. WENT AGAINST GUIDANCE AND DID BRING A GOOD MARINE LAYER WITH
COOLER TEMPS.

.LONG TERM...
THE IMPULSE ON FRIDAY CONTINUES TO FLUMMOX THE MEDIUM RANGE MODELS.
SATURDAYS FORECAST LOOKS ON TRACK WITH THE LOW MOVING OUT AND HGTS
RISING THE MARINE LAYER SHOULD SHRINK A LITTLE AND TEMPS SHOULD WARM
A FEW DEGREES.

AFTER SATURDAY THE MDLS GO THEIR OWN WAYS AND THE GFS ENSEMBLES
BOMB-BURST INTO A SQUIGGLY MESS. WITH LITTLE OR NO CONFIDENCE IN THE
LONG RANGE FORECAST MADE A FEW ADJUSTMENT TOWARD CLIMATOLOGY BUT IN
GENERAL LEFT THINGS UNCHANGED FROM SUNDAY ON. HOPEFULLY THE MODELS
WILL GET A HANDLE ON FRIDAYS IMPULSE AND THE MEDIUM RANGE MDLS WILL
GET A HANDLE ON THINGS.

&&

.AVIATION...

17/1100Z

MARINE LAYER IS NEAR 1300 FEET AND PUSHED IN NICELY BY A 3 MB
GRADIENT. CIGS ARE HIGH ENOUGH TO MAKE IT INTO THE VLYS BUT WILL
ALSO BE HIGH ENOUGH TO NOT PRESENT MUCH OF VISIBILITY PROBLEM. THE
CENTRAL COAST WILL BE SLOW TO CLEAR. THE MARINE CLOUD PATTERN THIS
EVENING AND OVERNIGHT SHOULD BE VERY SIMILAR TO YDY NIGHT.

KLAX...VERY GOOD CONFIDENCE IN 12Z TAF. CIG CLEARING WILL VERY
LIKELY BE WITHIN AN HOUR OF FORECAST.

KBUR...GOOD CONFIDENCE IN TH 12Z TAF. CIG BURN OFF COULD BE ONE OR
TWO HOURS LATER THAN FORECAST. CIG ARRIVAL TONIGHT WILL BE AFTER
MIDNIGHT AND MORE LIKELY TOWARD DAWN.

&&

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

&&

$$

PUBLIC...RORKE
AVIATION...BRUNO

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