000
FXUS66 KLOX 160424
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
915 PM PDT MON SEP 15 2008

.SHORT TERM...
WITH A VERY SHALLOW AND STRONG INVERSION LESS THAN 600 FT DEEP
ACROSS THE AREA TODAY...AS WELL AS WEAK ONSHORE
GRADIENTS...TEMPERATURES SOARED ACROSS MUCH OF LOS ANGELES AND
VENTURA COUNTIES TODAY. ALTHOUGH TEMPS WERE QUITE WARM JUST ABOUT
EVERYWHERE AWAY FROM THE IMMEDIATE COAST...SANTA CLARITA AND THE SAN
FERNANDO VALLEYS SOARED TO BETWEEN 100 AND 105 DEGREES...WITH SANTA
CLARITA VALLEY REACHING
106 AT ONE LOCATION...WHILE OJAI CLIMBED TO 102 DEGREES. DOWNTOWN
LOS ANGELES WARMED UP TO 87 DEGREES. ABOVE THE INVERSION...MALIBU
HILLS REACHED 103 DEGREES. THE INTERIOR SECTIONS OF SLO/SBA COUNTIES
REACHED THE MID 90S TO NEAR 100.

CURRENTLY...LATEST SATELLITE IMAGERY INDICATED CLEAR SKIES ACROSS
ALL OF SRN CAL S OF POINT CONCEPTION...WHILE AREAS OF LOW CLOUDS
WILL BEGINNING TO FILL IN ACROSS CENTRAL COAST. SOME WEAK SUNDOWNER
WINDS HAVE DEVELOPED ACROSS PORTIONS OF THE SANTA BARBARA SOUTH
COAST AND FOOTHILLS WITH NORTH TO NORTHEAST GUSTS TO 35 MPH REPORTED
NEAR MONTECITO. SBA-SMX GRADS WERE -4.7MB. SURPRISED THAT WINDS HAVE
NOT BEEN STRONGER. BUT GRADS SHOULD RELAX AFTER MIDNIGHT.

HIGH PRESSURE ALOFT WILL BEGIN TO GET NUDGED EASTWARD WHILE A WEAK
NEGATIVE TILTED TROF PUSHES DOWN ACROSS THE CAL COAST ON TUE. TEMPS
WILL HAVE TO BE ADJUSTED LOWER ACROSS THE BOARD AS 950 MB
TEMPS...THICKNESS LVLS INDICATE SOME LOWERING DUE TO TROF. STILL
ANTICIPATE WARMER THAN NORMAL TEMPS ACROSS THE REGION...WITH SANTA
CLARITA LIKELY RISING TO OVER 100 DEGREES ONCE AGAIN TUESDAY...BUT
FEEL THAT ONSHORE PUSH WILL START A BIT EARLIER KEEPING AREAS LIKE
BURBANK NEAR 90 AND DOWNTOWN POSSIBLY A DEGREE OR TWO COOLER.
CURRENT FORECAST SHOWS INCREASE FOR TUESDAY AND WILL HAVE TO BE
ADJUSTED BY MIDNIGHT SHIFT.

THERE WILL BE SOME INCREASING MID LEVEL MOISTURE PUSHING ACROSS THE
INTERIOR SECTIONS OF SOUTHWEST CALIFORNIA TOMORROW. ALTHOUGH MANY
CONVECTIVE PARAMETERS WILL BE MARGINAL ACROSS THE MOUNTAINS OF LOS
ANGELES AND VENTURA COUNTY AS WELL AS THE ANTELOPE VALLEY...PWAT
VALUES WILL BE NEAR AN INCH AND K-INDEX VALUES CLIMB TO NEAR 35
ACROSS THE EASTERN LA COUNTY MTNS. WITH CONTINUED ABOVE NORMAL TEMPS
FOR THE MOUNTAINS AND ANTELOPE VALLEY...THE CONVECTIVE TEMPS COULD
BE REACHED...SO A SLIGHT CHANCE OF TSTMS LOOK GOOD AT THIS TIME.

...FROM PREVIOUS DISCUSSION...

FOR TUESDAY NIGHT AND WEDNESDAY...THE FLOW ALOFT WILL SHIFT TO THE
SOUTHWEST AND COMBINED WITH SLIGHT COOLING AND DECREASED INSTABILITY
ACROSS THE REGION...ONLY AFTERNOON CLOUDS WILL BE MENTIONED ACROSS
THE MOUNTAINS AND DESERTS FOR WEDNESDAY AFTERNOON. LATER SHIFTS WILL
NEED TO MONITOR THIS AS THERE MIGHT BE ENOUGH INSTABILITY FOR A
THUNDERSTORM OR TWO.

MEANWHILE...A SLIGHT INCREASE IN ONSHORE FLOW MAY BE ENOUGH TO
INSPIRE AN INCREASE IN MARINE CLOUD COVERAGE FOR COASTAL SECTIONS
SOUTH OF POINT CONCEPTION.

.LONG TERM...GFS AND EC ARE NOW IN AGREEMENT THROUGH MONDAY AS THEY
DEPICT A SMALL LOW MOVING INTO NORTHERN CALIFORNIA. LOOK FOR TROFING
PATTER THROUGH FRIDAY WHICH SHOULD GIVE US NIGHT AND MORNING CLOUDS
OVER THE COASTS AND MOST OF THE VLYS. THE WEEKEND MAY BRING A SLIGHT
WARMUP AS THE LOW PUSHES EAST OF THE REGION.

&&

.AVIATION...15/1745Z
MARINE LAYER BETWEEN 008-012...WITH A FAIRLY SCATTERED STRATUS
PATTERN. OTHER THAN CIGS AT KSMX AND SOME HZ AT KOXR KLAX AND
KLGB...ALL AIRPORTS ARE VFR. VFR CATS SHOULD PREVAIL EVERYWHERE
AFTER 19Z. WESTERLY WINDS WILL BE STRONGER THAN NORMAL ALONG THE
COAST...WITH SOME GUSTS ABOVE 15 KT EXPECTED AT KSBA KOXR AND KLAX.
MODERATE CONFIDENCE OF SIMILAR STRATUS AT KSMX AND KSBP. LOW
CONFIDENCE IN WHAT STRATUS WILL DO AT KOXR KLAX AND KOXR...BUT BEST
CHANCE OF STAYING CIG FREE.

KLAX...HIGH CONFIDENCE IN VFR FROM 20Z THROUGH EARLY THIS EVENING.
STRONGER THAN NORMAL WEST WIND EXPECTED THIS AFTERNOON. LOW
CONFIDENCE IN RETURN OF STRATUS TONIGHT...BUT MODERATE CONFIDENCE IN
SOME MVFR HAZE AFTER 12Z.

KBUR...HIGH CONFIDENCE IN VFR THROUGH TONIGHT.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING (SEE LAXRFWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).

&&

$$

PUBLIC...KAPLAN/SWEET
AVIATION...KITTELL

WWW.WEATHER.GOV/LOSANGELES