329
FXUS66 KLOX 281128
AFDLOX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
428 AM PDT MON JUL 28 2025
UPDATED AVIATION SECTION
SYNOPSIS
28/107 AM.
ONSHORE FLOW WILL CONTINUE THROUGH THE WEEK AS AN UPPER-LEVEL
TROUGH OF LOW PRESSURE REMAINS ANCHORED ALONG THE WEST COAST. NIGHT
THROUGH MORNING LOW CLOUDS AND FOG WILL REMAIN IN THE FORECAST
FOR MOST COASTAL AND VALLEY LOCATIONS, BUT THE MARINE LAYER WILL
THIN SOME THROUGH MIDWEEK AS HIGH PRESSURE ALOFT THE SOUTHEASTERN
UNITED STATES BUILDS WEST. A SLOW WARMING TREND WILL TAKE SHAPE,
MOST PRONOUNCED AWAY FROM THE COAST.
SHORT TERM (TDY-WED)
28/252 AM.
THE LATEST WATER VAPOR IMAGERY SHOWS SOUTHWEST FLOW ALOFT IN
PLACE EARLY THIS MORNING AS THE REGION REMAINS SANDWICHED BETWEEN
AN UPPER-LEVEL TROUGH OVER THE WEST COAST AND A BROAD RIDGE OF
HIGH PRESSURE OVER THE SOUTHEASTERN UNITED STATES. LOW CLOUDS AND
FOG ARE WELL-ENTRENCHED ALONG THE CENTRAL COAST THIS MORNING, BUT
THE LOW CLOUD FIELD CONTINUES TO STRUGGLE TO DEVELOP ACROSS THE
SOUTHERN CALIFORNIA BIGHT. THE CLOUDS ARE STRUGGLING TO FORM
BECAUSE THE LOW LEVEL FLOW PATTERN IS FIGHTING THE EDDY CIRCULATION
SOMEWHAT AND CUTTING OFF THE MOISTURE ADVECTION. THE NORMAL SOUTH
TO SOUTHEAST WINDS ALONG THE SOUTH COAST OF CALIFORNIA WITH AN
EDDY ARE NOTICEABLY ABSENT. DESPITE THE RESISTANCE FROM THE LOW-
LEVEL FLOW PATTERN, THE EDDY IS TRYING TO REMAIN INTACT. STILL,
NOT ONE BUT TWO EDDY CIRCULATIONS CAN BE SEEN IN THE BIGHT, ONE IN
THE SANTA BARBARA CHANNEL, AND THE OTHER JUST OUTSIDE THE SANTA
MONICA. THE ONE IN THE SANTA BARBARA CHANNEL SEEMS TO BE WELL-
DEVELOPED AND CLOUDS SHOULD EXPECTED TO FILL INTO THE SANTA MONICA
BAY AND EASTERN PORTION SANTA BARBARA CHANNEL AS THE MORNING
PROGRESSES.
MODERATELY TO STRONG ONSHORE FLOW REMAINS IN PLACE ACROSS THE AREA
THIS MORNING AND WILL LIKELY STICK AROUND THROUGH TODAY, BUT
ONSHORE FLOW IS PROGGED TO WEAKEN OVER THE COMING DAYS. ENSEMBLE
SURFACE PRESSURE GRADIENTS INDICATE WEAKENING TAKING PLACE ALONG
THE SOUTH COAST OF CALIFORNIA, BUT MODERATE TO STRONG ONSHORE FLOW
IS LIKELY TO REMAIN WEDGED IN ALONG THE CENTRAL COAST OF
CALIFORNIA. THE ONSHORE FLOW REGIME WILL WEAKEN FOR AREAS SOUTH OF
POINT CONCEPTION DUE TO THE INFLUENCE OF THE RIDGE BUILDING WEST
OVER THE COMING DAYS. WHILE TO THE NORTH, THE FLOW REGIME WILL
VARY LITTLE DUE TO THE PERSISTENT TROUGH. THE MARINE LAYER DEPTH
WILL THIN ACROSS THE SOUTHLAND, BUT ALONG THE CENTRAL COAST,
CLOUDS WILL LIKELY STRUGGLE TO CLEAR FROM THE LAND MASS EACH DAY.
WITH 500 MB HEIGHTS INCREASING EACH DAY AND THE MARINE LAYER DEPTH
NOT CHANGING MUCH, CLOUDS ARE LIKELY TO SOCK IN THE BEACHES ALONG
THE CENTRAL COAST. EPS CLOUD COVER MEANS AGREE WITH THIS
ASSESSMENT, KEEPING CLEARING AT A MINIMUM FOR K87Q, KVBG, AND
KLPC. MEANWHILE, BETTER CLEARING AND LESS MARINE LAYER COVERAGE
WILL OCCUR ACROSS THE SOUTHLAND.
WITH HEIGHTS CLIMBING, A GRADUAL WARMING TREND WILL ESTABLISH,
ESPECIALLY OUTSIDE OF THE MARINE LAYER DEPTH. THE AIR MASS SHOULD
POP ABOVE NORMAL TOWARD MIDWEEK ACROSS THE HIGHER VALLEYS,
MOUNTAINS, AND DESERT, WHILE TEMPERATURES WILL LIKELY REMAIN ON
THE COOL SIDE OF NORMAL AT THE BEACHES AND IMMEDIATE COASTAL
LOCALES. PERSISTENCE MAY END UP BEING THE BEST FORECAST FOR THE
CENTRAL COAST BEACHES THROUGH MIDWEEK.
WITH THE COOLER AIR MASS TO THE NORTHWEST OF THE AREA AND A WARMER
AIR MASS OVER SOUTHEASTERN CALIFORNIA, A TIGHTER NORTHWEST SURFACE
GRADIENT SHOULD DEVELOP. GUSTY SUNDOWNER WINDS WILL LIKELY ENTER
THE PICTURE, POSSIBLY REACHING ADVISORY LEVELS ON TUESDAY AND
WEDNESDAY EVENINGS. WEDNESDAY EVENING LOOKS TO BE THE MOST LIKELY
PERIOD FOR ADVISORY LEVEL WINDS TO DEVELOP. KSBA-KSMX SURFACE
PRESSURE GRADIENTS TIGHTEN AROUND -3.5 MB BOTH EVENING, BUT THE
LOW-LEVEL PATTERN IS A TAD MORE SUPPORTIVE ON WEDNESDAY EVENING.
LONG TERM (THU-SUN)
28/236 AM.
ANOTHER WEAK TROUGH WILL MOVE OVER CENTRAL CALIFORNIA ON WEDNESDAY
AND LIKELY INCREASE ONSHORE FLOW AND DEEPEN THE MARINE LAYER DEPTH
WEDNESDAY NIGHT AND INTO THURSDAY. THEN, EPS AND GEFS ENSEMBLE
MEMBERS INDICATE 500 MB HEIGHTS CLIMBING AGAIN FOR LATE WEEK. A
WARMING TREND SHOULD RESUME BETWEEN THURSDAY AND SATURDAY.
ALTHOUGH THERE IS A QUITE A BIT OF SPREAD BETWEEN THE
PERTURBATIONS OF EACH ENSEMBLE, WPC CLUSTER ANALYSIS FAVORS A
SIMILAR UPPER-LEVEL PATTERN REMAINING IN PLACE WITH 500 MB
HEIGHTS INCREASING THROUGH AT LEAST FRIDAY. THERE IS A GOOD CHANCE
OF COOLING OVER THE WEEKEND.
AVIATION
28/1128Z.
AT 1012Z AT KLAX, THE MARINE LAYER WAS AROUND 1700 FT DEEP. THE
TOP OF THE INVERSION WAS AT 3200 FEET WITH A MAX TEMPERATURE OF
20 C.
HIGH CONFIDENCE IN VFR TAFS FOR KWJF AND KPMD.
LOW CONFIDENCE IN TAFS FOR KPRB WHERE THERE IS A 30% CHANCE OF
CONDITIONS REMAINING VFR AT THROUGH THE PERIOD, BUT IF CIGS REACH,
THERE IS A 40% CHANCE FOR LIFR CONDS. FOR TONIGHT, THERE IS A 30%
CHANCE FOR LIFR TO IFR CONDS AFTER 10Z.
MODERATE CONFIDENCE IN REMAINING TAFS. MINIMUM CIG HEIGHT MAY BE
OFF BY +/- 300 FT. DISSIPATION OF OF CIGS MAY BE OFF BY +/- 90
MINUTES. ARRIVAL TONIGHT MAY BE OFF +/- 3 HOURS. THERE IS A 30%
CHANCE FOR NO LOW CLOUDS AT KBUR OR KVNY TONIGHT. FOR KSMX AND
KSBP, THERE IS A 15% CHANCE FOR VSBYS LESS THAN 2SM AFTER 07Z
TUES.
KLAX...MODERATE CONFIDENCE IN TAF. DISSIPATION MAY BE OFF +/- 90
MINUTES. ARRIVAL TONIGHT MAY BE OFF +/- 2 HOURS. MINIMUM CIG
HEIGHT MAY BE OFF +/- 300 FT. MODERATE CONFIDENCE THAT ANY EAST
WIND COMPONENT WILL REMAIN BELOW 6 KTS.
KBUR...MODERATE CONFIDENCE IN TAF. DISSIPATION MAY BE OFF +/- 90
MINUTES. ARRIVAL TONIGHT MAY BE OFF +/- 3 HOURS. MINIMUM CIG
HEIGHT MAY BE OFF +/- 300 FT. THERE IS A 30% CHANCE FOR NO LOW
CLOUDS TONIGHT.
MARINE
28/231 AM.
HIGH CONFIDENCE IN UNSEASONABLY SMALL (BUT CHOPPY) SEAS THROUGH
TUESDAY MORNING, THEN SEAS ARE LIKELY TO BUILD TO 6-8 FEET ACROSS
THE OUTER WATERS TUESDAY NIGHT AND LAST THROUGH THE WEEK. HIGH
CONFIDENCE IN SMALL CRAFT ADVISORY (SCA) WINDS FOR THE OUTER
WATERS AND INNER WATERS ALONG THE CENTRAL COAST THROUGH THURSDAY
NIGHT, WITH THE EXCEPTION OF LULL THIS MORNING FOR THE WATERS
SOUTH OF PT SAL. HOWEVER, LOCAL SCA LEVEL GUSTS ARE POSSIBLE
THROUGH 6 AM PDT THIS MORNING. NEARSHORE SCA LEVEL WINDS ALONG
THE CENTRAL COAST WILL BE CONFINED TO AFTERNOON AND EVENING HOURS.
MODERATE CONFIDENCE IN WINDS CONTINUING INTO FRIDAY AND OVER THE
WEEKEND.
FOR WEDNESDAY NIGHT, THERE IS A A 30% CHANCE OF LOW- END GALES FOR
THE OUTER WATERS, WITH BEST CHANCES FROM AROUND POINT CONCEPTION
SOUTH TO SAN NICOLAS ISLAND.
THE WESTERN PORTION OF THE SANTA BARBARA CHANNEL WILL REACH SCA
DURING THE EVENINGS THOUGH AT LEAST THURSDAY. THERE IS A MODERATE
CHANCE FOR WINDS TO EXTEND INTO EASTERN PORTIONS OF THE CHANNEL
THROUGH THURSDAY, WITH HIGHEST CHANCES WEDNESDAY. LOCAL GUSTS TO
20 KT MAY OCCUR EACH AFTERNOON AROUND PT DUME AND INTO THE SAN
PEDRO CHANNEL.
LOX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT FROM 3 PM THIS AFTERNOON TO 9
PM PDT THIS EVENING FOR ZONES 645-650. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PDT WEDNESDAY FOR
ZONE 670. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT FROM 3 PM THIS AFTERNOON TO 3
AM PDT WEDNESDAY FOR ZONES 673-676. (SEE LAXMWWLOX).
PUBLIC...HALL
AVIATION...LEWIS
MARINE...LEWIS
SYNOPSIS...HALL
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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