Area Forecast Discussion
Issued by NWS Los Angeles, CA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS66 KLOX 051224
AFDLOX

SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
430 AM PDT SUN JUL 5 2015

NEW AVIATION DISCUSSION

.SYNOPSIS...UPPER LEVEL LOW PRESSURE OFF THE COAST WILL MAINTAIN
NIGHT THROUGH MORNING LOW CLOUDS AND FOG IN COASTAL AND MOST VALLEY
AREAS THROUGH TUESDAY...WITH TEMPERATURES GENERALLY NEAR TO SLIGHTLY
BELOW NORMAL. LOW PRESSURE WILL APPROACH AND MOVE INTO CENTRAL
CALIFORNIA WEDNESDAY THROUGH FRIDAY...BRINGING A DEEPER MARINE LAYER
AND GENERALLY BELOW NORMAL TEMPERATURES. SOME WARMING IS EXPECTED
NEXT WEEKEND AS THE UPPER LOW MOVES AWAY FROM THE REGION.

&&

.SHORT TERM (TODAY-TUE)...MARINE LAYER HAS DEEPENED DURING THE PAST
24 HOURS...AND WAS NOW AROUND 2000 FEET DEEP. ONSHORE PRESSURE
GRADIENTS HAVE STRENGTHENED AS WELL. STRATUS HAS PUSHED INTO ALL
COASTAL AREAS...AND UNLIKE YESTERDAY AT THIS TIME...HAS ALSO PUSHED
INTO MOST VALLEY AREAS AS WELL. THE EXCEPTIONS WERE THE SANTA
CLARITA VALLEY AND THE INTERIOR VALLEYS OF SLO COUNTY. CLOUDS MAY
PUSH INTO THESE AREAS BEFORE DAYBREAK. WITH STRONG ONSHORE GRADIENTS
UP TO NEAR 9 MB BETWEEN KLAX AND KDAG THIS AFTERNOON AND A STRONG
INVERSION IN PLACE...EXPECT CLEARING TO BE SLOW ONCE AGAIN NEAR THE
COAST. JUST LIKE ON SAT...EXPECT CLOUDS TO LINGER ALL DAY AT SOME
BEACHES FROM SRN SBA COUNTY THROUGH L.A. COUNTY. MAX TEMPS SHOULD BE
DOWN A FEW MORE DEGREES IN MOST AREAS TODAY. GUSTY SW TO W WINDS ARE
EXPECTED THROUGH THE SOLEDAD PASS AND ACROSS THE ANTELOPE VALLEY
THIS AFTERNOON AND EVENING...BUT AT THIS POINT...EXPECT WINDS TO
REMAIN JUST BELOW ADVISORY LEVELS. THE WRF CONTS TO SHOW A POCKET OF
STRONGLY NEGATIVE LIFTED INDEX VALUES ACROSS THE MTNS...ESPECIALLY
IN VTU COUNTY...BUT WITH LITTLE IN THE WAY OF MOISTURE WITH WHICH TO
WORK...EXPECT SOME BUILDUPS AT MOST TODAY.

THE UPPER LOW WELL TO THE WEST OF POINT CONCEPTION IS FORECAST TO
MOVE LITTLE THRU TUE. EXPECT MOSTLY MINOR DAY TO DAY CHANGES IN THE
WEATHER ACROSS THE REGION THRU TUE...WITH NIGHT/MORNING LOW CLOUDS
AND FOG IN COASTAL AND MOST VALLEY LOCATIONS...AND SLOW CLEARING
NEAR THE BEACHES. MAX TEMPS SHOULD NOT DIFFER TOO MUCH FROM DAY TO
DAY...ALTHOUGH THERE MAY BE SOME SLIGHT COOLING EACH DAY IN THE MTNS
AND DESERTS. THE WRF DOES SHOW SOME INCREASED N-S GRADIENTS ACROSS
SBA COUNTY MONDAY AND TUESDAY...SO EXPECT SOME GUSTY NW TO N WINDS
THROUGH AND BELOW PASSES AND CANYONS OF SRN SBA COUNTY LATE EACH
AFTERNOON AND EVENING. AS A RESULT...EXPECT MUCH LATER ARRIVAL OF
ANY STRATUS TO THE S COAST OF SBA COUNTY MON NIGHT AND TUE NIGHT.

.LONG TERM (WED-SAT)...THE UPPER LOW WILL BEGIN TO MOVE SLOWLY EWD
TUE NIGHT AND WED. THE MARINE LAYER SHOULD DEEPEN...AND NIGHT THRU
MORNING LOW CLOUDS MAY PUSH INTO THE LOWER COASTAL SLOPES. THERE
COULD ALSO BE SOME DRIZZLE. MAX TEMPS SHOULD BE DOWN A BIT MORE IN
MOST AREAS. THE UPPER LOW IS FORECAST TO TRACK INTO MRY OR SLO
COUNTY ON THU. THE MARINE LAYER WILL REMAIN DEEP...WITH NIGHT THRU
MORNING CLOUDS TO THE COASTAL SLOPES AND SOME DRIZZLE POSSIBLE.
THERE MAY ONLY BE PARTIAL CLEARING WEST OF THE MTNS ON THU. WOULD
NOT BE SURPRISED IF THERE IS SOME MEASURABLE LIGHT RAIN IN SOME
AREAS ON THU...PARTICULARLY ACROSS SLO AND SBA COUNTIES AND IN THE
FOOTHILLS OF L.A. COUNTY. MAX TEMPS SHOULD BE DOWN A COUPLE OF
DEGREES...WITH TEMPS GENERALLY WELL BELOW NORMAL FOR JULY. THE UPPER
LOW WILL LIFT NE AND WKN THU NIGHT AND FRI...BUT A TROUGH WILL HANG
BACK OVER THE REGION. THEREFORE...EXPECT THE MARINE LAYER TO REMAIN
FAIRLY DEEP...AND ANY WARMING SHOULD BE LIMITED. HEIGHTS WILL RISE
ACROSS THE REGION ON SAT AS A STRONG UPPER HIGH OVER THE S CENTRAL
US EXPANDS WWD. THIS SHOULD BRING SOME DECREASE IN THE MARINE LAYER
DEPTH...A REDUCTION IN NIGHT THROUGH MORNING STRATUS IN THE
VALLEYS...AND SOME WARMING TO MOST AREAS ON SAT.

&&

.AVIATION...

05/1130Z

AT 0800Z...THE MARINE INVERSION AT KLAX WAS BASED AT 2200 FEET. THE
TOP OF THE INVERSION WAS 4600 FEET WITH A TEMPERATURE OF 23 DEGREES
CELSIUS.

FAIRLY GOOD CONFIDENCE IN TAFS WITH A 30 PERCENT CHANCE OF NO
CLEARING AT EVERY CSTL TAF SITE. TRANSITION TO VFR CONDS COULD BE AN
HOUR LATER THAN FCST. GOOD CONFIDENCE IN EARLY RETURN OF CIGS THIS
EVENING TO ALL CSTL SITES.

KLAX...FAIRLY GOOD CONFIDENCE IN TAF. THERE IS A 30% CHANCE THAT
CIGS WILL NOT SCATTER OUT THIS AFTERNOON. THERE IS A 30% CHC THAT
CIGS WILL LAST UNTIL 21Z.

KBUR...GOOD CONFIDENCE IN TAF.

&&

.MARINE...

05/300 AM

OUTER WATERS...HIGH CONFIDENCE IN WEST TO NORTHWEST WINDS REMAINING
BELOW SMALL CRAFT ADVISORY LEVELS THROUGH MONDAY(ALTHOUGH THERE MAY
BE SOME LOCAL GUSTS TO 25 KT IN THE AFTERNOON AND EVENING HOURS).
SMALL CRAFT ADVISORY CONDITIONS WILL LIKELY DEVELOP TUESDAY AND
CONTINUE INTO WEDNESDAY OR THURSDAY.

INNER WATERS...HIGH CONFIDENCE IN WESTERLY WINDS REMAINING BELOW
SMALL CRAFT ADVISORY LEVELS THROUGH MONDAY. WINDS WILL INCREASE SOME
STARTING MONDAY NIGHT. THERE WILL BE SMALL CRAFT ADVISORY LEVEL
GUSTS ACROSS WESTERN SECTIONS EACH AFTERNOON AND EVENING THROUGH
THURSDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
NONE

&&

$$

PUBLIC...DB
AVIATION/MARINE...RORKE
SYNOPSIS...DB

WWW.WEATHER.GOV/LOSANGELES


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.