000
FXUS66 KLOX 161620
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
920 AM PDT TUE SEP 16 2008

.SHORT TERM...SIMI VALLEY PROFILER AND NKX/VBG SOUNDINGS ALL SHOWING
WARMING IN THE LOW LVLS TODAY WHICH IS SUPPORTED BY MANY
OBSERVATIONS THIS MORNING, ESPECIALLY INLAND. ALTHOUGH SOME OF THIS
IS LIKELY DUE TO A SLIGHTLY WARMER START TO THE DAY I THINK THERE IS
ENUOGH WARM AIR IN PLACE COMBINED WITH SLIGHTLY STRONGER OFFSHORE
FLOW TO KEEP TEMPS AT LEAST AT MONDAY`S LEVELS. UPDATED THE ZONES
THIS MORNING TO BUMP UP HIGHS A FEW DEGREES AND TO INCLUDE PARTLY
CLOUDY MOST ZONES TODAY DUE TO THE THIN LAYER OF MID LEVEL MOISTURE
MOVING OVERHEAD.

THE POTENTIAL FOR CONVECTION TODAY APPEARS TO BE LOWER THAN
PREVIOUSLY THOUGHT. MOISTURE IS VERY LIMITED AND CONFINED TO A VERY
NARROW LAYER. INSTABILITY INDICES AREN`T OVERLY IMPRESSIVE. STILL
HOWEVER, PARAMETERS AREN`T DOWN ENOUGH TO CONFIDENTLY REMOVE STORMS
FROM THE FORECAST SO WILL LEAVE IN A SLIGHT CHANCE THIS AFTERNOON
AND EVENING.

ON A PROCEDURAL NOTE, THE LOS ANGELES COUNTY VALLEY ZONE (ZONE 47)
HAS BEEN SPLIT INTO TWO ZONES THAT INCLUDE THE SAN FERNANDO VALLEY
(ZONE 547) AND SAN GABRIEL VALLEY (ZONE 548). THE UPDATED ZONES THAT
WERE ISSUED EARLIER INCLUDE THESE NEW ZONES. ALL FUTURE PUBLIC AND
FIRE WEATHER PRODUCTS WILL INCLUDE THE NEW ZONES.

...REMAINDER FROM PREVIOUS DISCUSSION...

THE GALE IN THE OUTER WATERS WILL SPIN AN EDDY UP TONIGHT AND THIS
WILL BRING LOW CLOUDS TO THE L.A. COAST AND PATCHY CLOUDS TO
VENTURA. THERE WILL BE BETTER ONSHORE FLOW AND LOWER HGTS AS WELL AS
A DEEPER MARINE LAYER AND ALL AREAS SHOULD COOL EXCEPT THE CENTRAL
COAST WHICH WILL REMAIN COOL.

THE EDDY CONTINUES TO SPIN WEDNESDAY NIGHT AND THURSDAY BUT A LITTLE
NORTH PUSH SHOULD KEEP THE CLOUDS MOSTLY OUT OF THE VLYS (EXCEPT THE
SANTA YNEZ) THE NORTH PUSH WILL ALSO BRING ABOUT A WEAK SUNDOWNER
AND SOME I-5 CORRIDOR WINDS. THE LOWER HGTS WILL ALSO CONTINUE THE
COOLING TREND.

.LONG TERM...
GFS AND EC IN TOTAL DISAGREEMENT IN THE HANDLING OF AN UPPER LOW
THAT MOVES INTO NORTHERN CALIFORNIA LATE THURSDAY. THE EC OPENS IT
UP AND MOVES QUICKLY OUT INTO NRN NV WHILE THE GFS DEVELOPS A SLOW
MOVING CUT OFF LOW WHICH SPENDS MUCH OF THE EXTENDED PERIOD
MEANDERING OVER CALIFORNIA. GFS ENSEMBLES ALSO POINT OUT A VERY
CONFUSED PATTERN WITH LITTLE OR NO AGREEMENT IN ANY OF THE
PERTURBATIONS. THUS MADE LITTLE IN THE WAY OF CHANGES TO THE
EXTENDED PERIOD AND WILL HOPE FOR SOME SORT OF AGREEMENT IN FUTURE
RUNS.

&&

.AVIATION...

16/1130Z

MARINE LAYER NEAR 400 FEET AND ALL GRADIENTS OFFSHORE. SOUTH OF
POINT CONCEPTION THE ONLY AVIATION HAZARD WILL BE LOCAL HZ
RESTRICTIONS AROUND DAWN. NORTH OF POINT CONCEPTION LIFR CONDS WILL
LAST THROUGH MID MORNING. LOW CLOUDS WILL LIKELY REFORM FROM KLAX TO
KNTD LATE TONIGHT.

KLAX...HIGH CONFIDENCE IN TAF. A CHANCE OF 5SM HZ AFTER DAWN THROUGH
MID MORNING.

KBUR...HIGH CONFIDENCE IN CAVU TAF.

&&

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

&&

$$

PUBLIC...WOFFORD/RORKE
AVIATION...BRUNO

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