Area Forecast Discussion
Issued by NWS Los Angeles, CA

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000
FXUS66 KLOX 301836
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1130 AM PDT TUE SEP 30 2014

...NEW AVIATION DISCUSSION...

.SYNOPSIS...

THERE WILL BE ONE LAST DAY OF NEAR NORMAL TEMPERATURES BEFORE THEY
RISE SIGNIFICANTLY DURING THE NEXT SEVERAL DAYS.  BY THE WEEKEND...
AFTERNOON TEMPERATURES WILL BE WELL ABOVE NORMAL WITH THE HOTTEST
TEMPERATURES COMING ON SATURDAY AND ONLY SLIGHT COOLING ON SUNDAY
AND MONDAY.  WINDS WILL BE GUSTY AND DRY THROUGH THIS PERIOD AS WELL.

&&

.SHORT TERM (TODAY-THU)...
***MID MORNING DISCUSSION UPDATE***
LITTLE MARINE LAYER PUCH THIS MORNING THOUGH SOME LOCATIONS ALONG
THE CENTRAL COAST DID HAVE LOCALLY DENSE FOG.  THIS WILL CLEAR OUT
BY MID MORNING.

NO NOTABLE CHANGES ARE EXPECTED TO THE CURRENT FORECAST PACKAGE AT
THIS TIME.  GUIDANCE IS CONSISTENT REGARDING A NOTABLE HIGH PRESSURE
SETTING UP OFF AND ALONG THE PACIFIC COAST BUT NOT AS CONSISTENT AS
TO HOW IT SHIFTS WITH TIME OR HOW IT BEGINS TO COLLAPSE. FOCUS
OF THE DAY WILL BE ON THE TIMING OF THE HEAT BOTH COMING AND GOING
AS WELL AS A GOOD LOOK AT JUST HOW HOT IT WILL BECOME.  WINDS ARE
ALSO A CONCERN.

***EARLY MORNING DISCUSSION***
UNEXCITING 582 DM ZONAL NW FLOW OVER CALIFORNIA. BIGGER NEWS IS AT
THE SFC WHERE GRADIENTS ARE OFFSHORE BOTH FROM THE NORTH AND THE
EAST. THESE GRADIENTS HAVE KEPT ALL LOW CLOUDS AWAY EXPECT FOR A
LITTLE PATCH IN WESTERN SBA COUNTY AND THE SNS RIVER VLY. THE
OFFSHORE FLOW WILL GENERATE SOME MTN WINDS AND PERHAPS SOME 15 MPH
CANYON WINDS IN SOME VLY LOCATIONS SO NOT REALLY A SANTA ANA BUT
MORE IMPORTANTLY IT WILL DELAY OR ELIMINATE THE SEA BREEZE WHICH
WILL ALLOW FOR SEVERAL DEGREES OF WARMED COMPARED TO YDYS READINGS.

REAL TOUGH CLOUD FCST TONIGHT AS THE COMPETING STRATUS FORCES OF
OFFSHORE FLOW AND AN EDDY GO HEAD TO HEAD. NAM INDICATES THAT EDDY
WILL BRING STRATUS TO THE VTA AND L.A. COASTS. NORTH FLOW WILL BRING
SOME NORTH SLOPE CLOUDS TO SBA STA AND LA MTNS AS WELL AS CUYAMA
VLY. THE LOMPOC VANDENBERG AREA WILL PROBABLY ALSO SEE SOME LOW
CLOUDS. BUT TRUTHFULLY THERE IS A VERY GOOD CHANCE THAT THE SKIES
WILL JUST STAY CLEAR. OFFSHORE FLOW WILL WEAKEN A LITTLE AND THAT
WILL BRING A TOUCH OF COOLING TO THE CSTS AND VLYS WHILE THE
INTERIOR SHOULD REMAIN ABOUT THE SAME.

ON WEDNESDAY EVENING A FAST MOVING TROF ZIPS THROUGH NEVADA AND A
LARGE EAST PAC UPPER HIGH MOVES TOWARDS THE WEST COAST. AT THE SAME
TIME A STRONG COLD SFC HIGH MOVES INTO THE GREAT BASIN AND SETS UP
THE FIRST OFFSHORE WIND EVENT OF THE SEASON. THERE IS LITTLE TO NO
UPPER LEVEL WIND OR THERMAL SUPPORT SO NOT LOOKING FOR ANY GREAT
WIND EVENT BUT FAVORED SANTA ANA WIND AREAS WILL SEE NORTHEAST WINDS
15 TO 25 MPH WITH GUSTS TO 35 MPH AND PERHAPS 5 MPH HIGHER IN THE
MTNS. SKIES OF COURSE WILL BE CLEAR AND COAST AND VLY TEMPS WILL
SOAR. THERE WILL BE PLENTY OF 90 DEGREE READINGS TO GO AROUND IN THE
VLYS AND INTERIOR COASTAL SECTIONS.


.LONG TERM (FRI-MON)...
NOTHING BUT HEAT AND CLEAR SKIES FOR THE EXTENDED PERIOD. THE UPPER
HIGH WILL SIT ATOP OF THE STATE THROUGH SUNDAY. IT WILL PEAK WITH
592 DM HGTS SATURDAY. HGTS WILL SLOWLY FALL SUNDAY AND MONDAY UPPER
HIGH WILL BREAK DOWN INTO A RIDGE. STILL HGTS WILL BE 587DM. THERE
WILL BE PLENTY OF TRIPLE DIGIT HEAT IN THE VLYS AND THE INTERIOR OF
COASTAL SECTIONS ON SATURDAY WITH ABOUT 2 DEGREES OF COOLING EACH
DAY AFTER. MAYBE A LITTLE MORE RIGHT AT THE BEACHES. THERE WILL BE
PLENTY OF FIRE WEATHER CONCERNS MOLLIFIED ONLY BY THE LACK OF REAL
STRONG OFFSHORE WINDS.

&&

.AVIATION...30/1800Z.

MARINE LAYER AT KLAX AT 1803Z WAS 800 FEET DEEP AND THE INVERSION
TOP WAS 2700 FEET WITH A TEMPERATURE OF 22 DEGREES C.

PATCHY IS THE KEY WORD FOR TONIGHTS MARINE CLOUD FORECAST. THE
COASTAL TAF SITES IN LA COUNTY AND ON THE CENTRAL COAST ALL HAVE A
THREAT OF BKN SKIES AND IFR TO LIFR CONDITIONS TONIGHT...ALONG WITH
KPRB. AS FAR AS THE CONFIDENCE LEVEL...CONFIDENCE IS NOT VERY HIGH
AS TO THE TIMING AND LIKELIHOOD OF BKN SKIES. VALLEY AND DESERT TAFS
IN LA COUNTY WILL HAVE VFR CONDITIONS WITH HIGH CONFIDENCE.

KLAX...LOW CONFIDENCE IN THE 18Z TAF. THERE IS A 40 PERCENT CHANCE
OF VFR CONDITIONS THROUGH THE NIGHT.

KBUR...HIGH CONFIDENCE IN THE 18Z TAF.

&&

.MARINE...30/900 AM...

ACROSS THE OUTER WATERS...SMALL CRAFT ADVISORIES IN EFFECT FOR ALL
OUTER WATERS THROUGH TONIGHT (INCLUDING ZONE 645 THROUGH THIS
EVENING).

ACROSS THE INNER WATERS...HIGH CONFIDENCE IN WINDS REMAINING BELOW
SMALL CRAFT ADVISORY LEVELS THROUGH WEDNESDAY. BY LATE WEDNESDAY
NIGHT AND THURSDAY MORNING...MODERATE CONFIDENCE FOR WEAK TO LOCALLY
MODERATE OFFSHORE (NORTHEASTERLY) WINDS BETWEEN VENTURA AND MALIBU
AND POSSIBLY OUT TO THE CHANNEL ISLANDS. THERE IS MODERATE
CONFIDENCE IN WINDS REACHING LOW END SMALL CRAFT ADVISORY LEVELS
EARLY THURSDAY MORNING THROUGH NOON...ESPECIALLY NEAR SHORE BELOW
PASSES AND CANYONS. WEAKER OFFSHORE FLOW IS ANTICIPATED DURING THE
NIGHTTIME HOURS FRIDAY THROUGH THE WEEKEND...WITH WEAK ONSHORE FLOW
IN THE AFTERNOON HOURS.

A LONG PERIOD SOUTH-SOUTHWEST SWELL IS ANTICIPATED TO ARRIVE ON
WEDNESDAY AND CONTINUE THROUGH FRIDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH (SEE LAXRFWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).

&&
$$

PUBLIC...RORKE/KJ
AVIATION...SWEET
MARINE...SWEET
SYNOPSIS...KJ

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