016
FXUS66 KLOX 050249
AFDLOX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
749 PM PDT THU SEP 4 2025
SYNOPSIS
04/208 PM.
A SLIGHT COOLING TREND WILL KNOCK A FEW DEGREES OFF THE DAYTIME
HIGHS THROUGH THE WEEKEND, BRINGING TEMPERATURES BACK NEAR TO
SLIGHTLY BELOW NORMAL LEVELS. WITH ONSHORE FLOW INCREASING, THE
MARINE LAYER IS EXPECTED TO BECOME MORE COMMON ACROSS COASTAL
AREAS THIS WEEKEND. NEXT WEEK, A TROUGHING PATTERN WILL BRING
TEMPERATURES DOWN TO 6 TO 12 DEGREES BELOW NORMAL. THE MARINE
LAYER IS ALSO EXPECTED TO DEEPEN, PUSHING FURTHER INTO THE VALLEYS
WITH CHANCES FOR DRIZZLE. MONSOON MOISTURE IS NOT EXPECTED TO
RETURN FOR AT LEAST THE NEXT WEEK.
SHORT TERM (THU-SUN)
04/746 PM.
***UPDATE***
TODAY WAS RELATIVELY QUIET WITH WARM TEMPERATURES AND DRY WEATHER.
HUMIDITIES ARE EXPECTED TO REMAIN LOW OVER THE NEXT FEW DAYS, AND
AS PRESSURE FALLS, EXPECTING A DEEPENING MARINE LAYER AND
POTENTIAL FOR COASTAL CLOUDS TO EXPAND SOUTH OF POINT CONCEPTION.
MINIMAL CHANGES NEEDED, BUT MIGHT NEED TO DROP TEMPERATURES A BIT
ALONG THE CENTRAL COAST TO ALIGN CLOSER TO TODAY'S HIGHS.
***FROM PREVIOUS DISCUSSION***
LATEST SATELLITE SHOWS SOME LOW CLOUDS LINGERING ALONG THE
IMMEDIATE COASTLINE IN SLO/SBA COUNTIES AND CUMULUS CLOUDS ACROSS
THE SAN GABRIELS EARLY THIS AFTERNOON. CONVECTION WILL STRUGGLE TO
DEVELOP THIS AFTERNOON AND EVENING DUE TO LACK OF AVAILABLE
MOISTURE. SPC MESOSCALE ANALYSIS SHOWS PWATS ARE CURRENTLY BELOW
1" ACROSS OUR AREA. EVEN WITH THE LIMITING FACTORS, THERE IS STILL
A 10-15% CHANCE OF A THUNDERSTORM ACROSS THE SAN GABRIELS. MINIMAL
CHANCES ACROSS THE INTERIOR VENTURA MOUNTAINS. IF CONVECTIVE
INITIATION OCCURS, THE PRIMARY HAZARDS WOULD BE DRY LIGHTNING AND
GUSTY WINDS. THE FORECAST IS STILL ON TRACK WITH REGARDS TO TEMPS
AND HUMIDITY. SLIGHTLY ABOVE NORMAL TEMPERATURES WITH ABOVE
NORMAL HUMIDITY CAN BE EXPECTED THROUGH FRIDAY, WITH A COOLING
TREND TO NEAR TO SLIGHTLY BELOW NORMAL FOR MOST AREAS OVER THE
WEEKEND. AS FOR WINDS IN GENERAL, SUB-ADVISORY SUNDOWNERS AND
GUSTY WINDS ACROSS THE ANTELOPE VALLEY CAN BE EXPECTED EACH
EVENING THROUGH THE WEEKEND.
CATEGORY 4 HURRICANE KIKO WILL PRODUCE A SUFFICIENT AMOUNT OF
LATENT HEAT WHICH WILL HELP STRENGTHEN THE EASTERN PACIFIC RIDGE.
ONSHORE FLOW IS EXPECTED TO INCREASE THROUGH SATURDAY WHICH WILL
OFFSET ANY POTENTIAL INCREASE IN TEMPERATURES DUE TO MARINE LAYER
STRATUS ESPECIALLY ALONG THE COAST. ONLY A HANDFUL OF ENSEMBLE
MEMBERS SUPPORT A WARMING SOLUTION ON SATURDAY. THE MARINE LAYER
WILL BE MORE PRESENT SOUTH OF PT CONCEPTION THROUGH THE WEEKEND.
GRADIENTS SUPPORT SUB-ADVISORY SUNDOWNERS AND GUSTY ONSHORE WINDS
ACROSS THE ANTELOPE VALLEY EACH EVENING.
LONG TERM (MON-THU)
04/208 PM.
THE GFS AND ECMWF ARE IN GOOD AGREEMENT IN REGARDS TO LOCATION AND
TIMING OF AN UPPER-LEVEL TROUGH SITUATED ALONG THE WEST COAST NEXT
WEEK. THE BIGGEST DISCREPANCY IS THE STRENGTH AND SOUTHERN EXTENT,
IN WHICH THE GFS IS ON AVERAGE 3 DM LOWER IN HEIGHTS FOR ANY GIVEN
LOCATION ACROSS THE CWA. BOTH SOLUTIONS, (ALONG WITH A MODERATE
TO STRONG ONSHORE PUSH) WILL LIKELY PUSH MARINE LAYER STRATUS WELL
INTO THE VALLEYS KEEPING TEMPERATURES 6 TO 12 DEGREES BELOW NORMAL.
ALONG WITH PATTERN RECOGNITION, ENSEMBLE GUIDANCE HINTS AT THE
POSSIBILITY FOR DRIZZLE ACROSS COASTAL AND VALLEY AREAS. THE MARINE
LAYER MAY STRUGGLE TO CLEAR DURING THE DAY FOR SOME PLACES ALONG
THE IMMEDIATE COASTLINE. STRONG SW FLOW ALOFT WILL PREVENT MONSOON
MOISTURE ACROSS CALIFORNIA. THUS, AFTERNOON MONSOONAL CONVECTION
IS NOT EXPECTED NEXT WEEK.
AVIATION
05/0006Z.
AT 2335Z AT KLAX, THE MARINE LAYER WAS 900 FEET DEEP, WITH AN
INVERSION UP TO 2400 WITH A MAXIMUM TEMPERATURE OF 27 C.
HIGH CONFIDENCE IN TAFS FOR KPMD AND KWJF.
LOW CONFIDENCE IN TAFS FOR KPRB, KSBA, KBUR, KVNY DUE TO
UNCERTAINTY IN ARRIVAL AND POTENTIAL FLIGHT CAT OF CIGS. THERE IS
A 30-40% CHANCE FOR NOW LOW CLOUDS, HIGHEST AT KVNY AND KBUR.
FLIGHT CATS MAY BE OFF 1 CAT.
MODERATE CONFIDENCE IN REMAINING TAFS. ARRIVAL OF CIGS MAY BE OFF
+/- 2 HOURS, HIGHEST UNCERTAINTY FOR KOXR, KCMA, KSMO, KLAX, AND
KLGB. MINIMUM CIG HEIGHT MAY BE OFF +/- 300 FEET DUE TO
UNCERTAINTY OF THE STRENGTH OF THE CALIFORNIA EDDY. HIGHEST
UNCERTAINTY 12Z-18Z. CLEARING TIMES MAY BE OFF +/- 90 MINUTES.
KLAX...MODERATE CONFIDENCE IN TAF. CIGS MAY ARRIVE +/- 2 HOURS OF
FCST. MINIMUM CIG HEIGHT MAY BE OFF +/- 300 FEET AND CLEARING
TIMES MAY BE OFF +/- 90 MINUTES. THERE IS A 20% CHANCE OF AN EAST
WIND REACHING 8 KTS BETWEEN 12Z AND 18Z.
KBUR...LOW CONFIDENCE IN TAF. THERE IS A 40% CHANCE THAT NO CIGS
DEVELOP TONIGHT. IF THEY DO, MIN FLIGHT CAT MAY BE OFF BY 1 CAT.
MARINE
04/746 PM.
ACROSS THE OUTER WATERS, FAIRLY SEASONAL NW SMALL CRAFT ADVISORY
(SCA) WINDS ARE LIKELY THROUGH AT LEAST TUESDAY NIGHT, WITH LULLS
IN THE WINDS POSSIBLE DURING THE MORNING HOURS. SEAS WILL BE 5 TO
7 FEET THROUGH MONDAY.
ACROSS THE NEARSHORE WATERS NORTH OF POINT SAL, THERE IS A
MODERATE CHANCE FOR SCA WINDS EACH AFTERNOON AND EVENING THROUGH
TUESDAY.
FOR THE INNER WATERS SOUTH OF POINT CONCEPTION, THERE IS A
MODERATE CHANCE OF LOCALIZED SCA WINDS EACH AFTERNOON AND EVENING
ACROSS THE WESTERN PORTION OF THE SANTA BARBARA CHANNEL AND INTO
THE ANACAPA PASSAGE, NEAR POINT DUME, AND INTO THE SAN PEDRO
CHANNEL. SEAS WILL GENERALLY BE BELOW SCA LEVEL THROUGH SUNDAY,
THOUGH SOME WINDS WAVES WILL BE PRESENT IN THE EVENINGS. WINDS
WILL BECOME MORE WIDESPREAD ACROSS THE SANTA BARBARA CHANNEL MONDAY
AND TUESDAY, AND STEEPER SEAS WILL BE COMMON.
LOX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PDT SATURDAY FOR
ZONES 670-673-676. (SEE LAXMWWLOX).
PUBLIC...PHILLIPS/BLACK
AVIATION...LEWIS
MARINE...SCHOENFELD/LEWIS
SYNOPSIS...BLACK
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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