227
FXUS66 KLOX 152335
AFDLOX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
435 PM PDT THU MAY 15 2025
SYNOPSIS
15/121 PM.
A COOLING TREND IS EXPECTED FRIDAY THROUGH THE WEEKEND WITH SOME
MORNING DRIZZLE POSSIBLE SATURDAY. MUCH WARMER TEMPERATURES ARE
EXPECTED NEXT WEEK, ESPECIALLY INLAND AS HIGH PRESSURE BUILDS OVER
THE REGION.
SHORT TERM (TDY-SUN)
15/211 PM.
GRADIENTS ARE STARTING TO TREND ONSHORE TODAY AS THE LAST IN A
LONG SERIES OF MOSTLY WEAK TROUGHS MOVES THROUGH THE WEST COAST,
PEAKING LOCALLY ON SATURDAY. TEMPERATURES TODAY ENDED UP BEING
QUITE A BIT WARMER ACROSS THE INTERIOR, BUT LITTLE CHANGED NEAR
THE COAST.
AS THAT TROUGH ADVANCES SOUTHEAST THROUGH NORTHERN AND CENTRAL
CALIFORNIA FRIDAY AND SATURDAY, ONSHORE FLOW WILL CONTINUE TO
INCREASE AND PEAK SATURDAY AFTERNOON AT AROUND 9MB WITH COOLING
TEMPERATURES EACH DAY. AT THE SAME TIME, COOLING ALOFT WILL DEEPEN
THE MARINE LAYER CONSIDERABLY. LATEST FORECAST SOUNDING ACROSS
THE LA BASIN INDICATE THE MARINE INVERSION DEPTH RISING TO AROUND
2000 FEET FRIDAY, THEN UP TO 4000 FEET SATURDAY MORNING WITH A
SOLID 5MB GRADIENT. THIS COMBINATION OF FACTORS OFTEN, THOUGH NOT
ALWAYS, RESULTS IN SOME DRIZZLE ACROSS THE COAST AND VALLEYS. THE
ONE DRAWBACK IN THIS CASE IS THE UPPER LOW IS ACTUALLY TAKING A
MORE INSIDE PATH THROUGH CALIFORNIA WITH NORTHWEST FLOW ALOFT.
MOST OF THE MODELS DO FAVOR A RAPIDLY DEEPENING MARINE LAYER BUT
GIVEN THE INTERIOR TRAJECTORY AND WINDS ALOFT THE BEST CHANCES FOR
ANY DRIZZLE WOULD LIKELY BE THE SAN GABRIEL VALLEY IN EASTERN LA
COUNTY. FURTHER WEST IT WILL BE A BATTLE BETWEEN THE NORTHWEST
FLOW ALOFT AND THE MARINE LAYER EXPANDING FROM THE SOUTHEAST. BY
SATURDAY TEMPERATURES WILL AGAIN BE 5-15 DEGREES BELOW NORMAL.
GUSTY ONSHORE WINDS WILL DEVELOP IN THE AFTERNOON, ESPECIALLY
ACROSS THE ANTELOPE VALLEY.
WITH MODELS NOW IN AGREEMENT THAT THE FIRST TROUGH WILL TAKE A
MORE INLAND TRACK AND THE NEXT UPPER LOW ALSO MOVING FARTHER
INLAND THROUGH UTAH, THERE IS INCREASING CONFIDENCE THAT A SLOW
WARMING TREND WILL BEGIN SUNDAY WITH EARLIER CLEARING OF THE
MARINE LAYER, ESPECIALLY INLAND. MODEL FORECAST GRADIENTS ARE IN
LINE WITH THAT AS WELL INDICATING A 2-3MB OFFSHORE TREND.
LONG TERM (MON-THU)
15/208 PM.
CONFIDENCE REMAINS HIGH IN MUCH WARMER TEMPERATURES NEXT WEEK,
ESPECIALLY TUESDAY AND BEYOND AS HIGH PRESSURE BUILDS AND ONSHORE
FLOW WEAKENS. HIGHS IN THE 90S ARE EXPECTED IN THE VALLEYS AND
POSSIBLY SOME ISOLATED LOWER 100S ACROSS THE WESTERN SAN FERNANDO
VALLEY. INLAND COASTAL AREAS WILL AT LEAST REACH THE MID 80S AND
POSSIBLY LOWER 90S IN DOWNTOWN LA. WARMEST DAY ARE EXPECTED TO BE
TUE-THU, BUT WELL ABOVE NORMAL TEMPERATURES WILL CONTINUE AT LEAST
THROUGH NEXT FRIDAY. THERE STILL MAY BE A SHALLOW MARINE LAYER AT
THE COAST CREATING SOME AREAS OF DENSE FOG.
AVIATION
15/2333Z.
AT 2253Z AT KLAX, THE MARINE INVERSION WAS AROUND 900 FEET DEEP.
THE TOP OF THE INVERSION WAS 2200 FEET WITH A TEMPERATURE OF 18
DEGREES CELSIUS.
HIGH CONFIDENCE IN TAFS FOR KPRB, KPMD, AND KWJF.
MODERATE CONFIDENCE IN REMAINING TAFS. TIMING OF CIG/VSBY
RESTRICTIONS MAY BE OFF +/- 2 HOURS, WITH FLIGHT CATS OFF BY ONE.
THERE IS A 40% CHANCE OF VLIFR VSBYS & LIFR CIGS AT KSMX/KSBP
FROM 06Z TO 16Z FRI. THERE IS A 20% CHANCE OF LIFR CONDS AT KVNY
FROM 09Z TO 16Z FRI.
KLAX...MODERATE CONFIDENCE IN 00Z TAF. THERE IS A 25% CHANCE OF
IFR CIGS 008-009 AT SOME POINT BETWEEN 06Z TO 16Z FRI. NO
SIGNIFICANT EAST WIND COMPONENT EXPECTED.
KBUR...MODERATE CONFIDENCE IN 00Z TAF. THERE IS A 30-40% CHANCE
OF IFR CONDS AND A 10% CHANCE OF LIFR CIGS W/ VSBYS <1SM FROM 06Z
TO 16Z FRI.
MARINE
15/156 PM.
FOR THE OUTER WATERS THROUGH FRIDAY NIGHT, HIGH CONFIDENCE IN A
COMBINATION OF SMALL CRAFT ADVISORY (SCA) LEVEL WINDS AND SEAS,
WITH A LULL IN WINDS POSSIBLE IN THE MORNING HOURS EACH DAY. FOR
SATURDAY THROUGH MONDAY, HIGH CONFIDENCE IN A COMBINATION OF SCA
LEVEL WINDS AND SEAS CONTINUING WITH A 40-60% CHANCE OF GALE FORCE
WINDS SATURDAY EVENING THROUGH LATE SUNDAY, BEST CHANCES SUNDAY
AFTERNOON THROUGH LATE NIGHT. SEAS WILL BUILD TO AROUND 13 FEET
DURING THIS TIME. SCA WINDS AND POTENTIALLY SEAS WILL CONTINUE
INTO NEXT WEEK.
FOR THE INNER WATERS NORTH OF POINT SAL, THERE IS A 50-60% CHANCE
FOR SCA LEVEL WINDS IN THE AFTERNOON AND EVENING TODAY AND
FRIDAY. FOR SATURDAY THROUGH SUNDAY NIGHT, HIGH CONFIDENCE IN
COMBINATION OF SCA LEVEL WINDS AND SEAS WITH A 30-50% CHANCE OF
GALE FORCE WINDS SATURDAY EVENING THROUGH SUNDAY EVENING. SEAS WILL
BUILD TO AROUND 12 FEET DURING THIS TIME. FOR MONDAY, THERE IS A
MODERATE CHANCE OF SCA LEVEL WINDS AND SEAS CONTINUING.
FOR THE INNER WATERS SOUTH OF POINT CONCEPTION, MODERATE
CONFIDENCE IN SCA LEVEL WINDS OCCURING IN THE SANTA BARBARA
CHANNEL THROUGH LATE TONIGHT, WITH HIGHEST CHANCES IN THE WESTERN
PORTION. THERE IS A 30% CHANCE FOR SCA LEVEL WINDS IN THE
AFTERNOON AND EVENING HOURS TOMORROW IN SIMILAR AREAS. FOR
SATURDAY THROUGH SUNDAY NIGHT, HIGH CONFIDENCE IN SCA LEVEL WINDS
OCCURING, WITH A 40-50% CHANCE OF GALE FORCE WINDS SATURDAY
EVENING THROUGH SUNDAY EVENING ACROSS THE WESTERN HALF OF THE
SANTA BARBARA CHANNEL. STEEP AND CHOPPY SEAS OF AROUND 8 FEET ARE
POSSIBLE DURING THIS TIME FRAME. FOR MONDAY, WINDS AND SEAS WILL
LIKELY REMAIN BELOW SCA THRESHOLDS.
LOX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 9 PM PDT THIS EVENING
FOR ZONE 645. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PDT FRIDAY FOR ZONE
650. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PDT SATURDAY FOR
ZONES 670-673-676. (SEE LAXMWWLOX).
PUBLIC...MW
AVIATION...BLACK
MARINE...LEWIS
SYNOPSIS...MW
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