241
FXUS66 KLOX 151720
AFDLOX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1020 AM PDT THU MAY 15 2025
UPDATED AVIATION DISCUSSION
SYNOPSIS
15/930 AM.
SLIGHT WARMING IS EXPECTED TODAY WITH LIGHTER ONSHORE WINDS AS
HIGH PRESSURE BUILDS OVER THE AREA. A COOLING TREND IS EXPECTED
FRIDAY THROUGH THE WEEKEND WITH SOME MORNING DRIZZLE POSSIBLE
SATURDAY. MUCH WARMER TEMPERATURES ARE EXPECTED NEXT WEEK,
ESPECIALLY INLAND.
SHORT TERM (TDY-SAT)
15/941 AM.
***UPDATE***
MOST COAST AND VALLEY AREAS ARE COOLER NOW THAN 24 HOURS AGO BUT
EXPECTING THOSE TO CATCH UP IN MOST AREAS BY THIS AFTERNOON IF NOT
TREND SLIGHTLY WARMER THAN YESTERDAY. WEAK CYCLONIC FLOW STILL
LINGERS OVER THE AREA BUT HEIGHTS ARE RISING AND ONSHORE FLOW IS
STILL RELATIVELY LIGHT. OVERALL A LOW IMPACT WEATHER DAY WITH
TEMPERATURES WITHIN A FEW DEGREES OF NORMAL.
INCREASING ONSHORE FLOW FRIDAY AND SATURDAY WILL LOWER
TEMPERATURES AND BRING MORE MARINE LAYER TO THE AREA. IN ADDITION
INCREASING WINDS ARE EXPECTED, ESPECIALLY ACROSS THE ANTELOPE
VALLEY.
***FROM PREVIOUS DISCUSSION***
WEAK POS TILT TROFFING WILL COVER THE AREA FRI AND SAT. ONSHORE
FLOW WILL INCREASE EACH DAY BOTH TO THE NORTH AND EAST. THE
LOWERING HGTS, CYCLONIC FLOW AND INCREASING ONSHORE FLOW WILL ALL
JOIN UP TO PRODUCE A DEEPER AND MORE EXTENSIVE MARINE LAYER CLOUD
PATTERN.
THE LOW CLOUDS WILL CLEAR FRIDAY BUT MID AND HIGH LEVEL CLOUDS
WILL DRIFT OVERHEAD MAKING A MOSTLY CLOUDY DAY FOR AREA SOUTH OF
PT CONCEPTION.
A LOBE OF PVA PASSES OVER THE AREA SATURDAY. THIS WILL REALLY
DEEPEN THE MARINE LAYER AND WILL LIKELY PRODUCE SOME DRIZZLE.
THERE IS EVEN ENOUGH LIFT TO BRING A SLIGHT CHC OF LIGHT RAIN TO
THE SAN GABRIEL VLY AND THE EASTERN SAN GABRIEL MTNS. MODERATE
ONSHORE FLOW AND THE LIFT FORM THE TROF WILL LIKELY KEEP THE
MARINE LAYER CLOUDS OVERHEAD ALL DAY.
LOOK FOR TWO DAYS OF COOLING WITH 2 TO 4 DEGREES ON FRIDAY AND
THEN A DRAMATIC 4 TO 8 ADDITIONAL DEGREES ON SATURDAY. MAX TEMPS
ON FRIDAY WILL NOT ESCAPE THE 60S WHICH IS 10 TO 15 DEGREES BLO
NORMAL FOR THE VLYS.
LONG TERM (SUN-WED)
15/306 AM.
STILL NOT THE BEST CONFIDENCE IN THE SUNDAY FORECAST. THE MAJORITY
OF ENSEMBLES FAVOR LESS MARINE LAYER AND WARMING ACROSS THE CSTS
AND VLYS. THIS IS LIKELY DUE TO A SWITCH TO OFFSHORE FLOW FROM THE
NORTH (AS EVIDENCED BY COOLING ACROSS THE INTERIOR) STRONG
ONSHORE FLOW DEVELOPS TO THE EAST IN THE AFTERNOON AND THIS WILL
BRING GUSTY WINDS TO THE CSTS AND THE ANTELOPE VLY AND IT MIGHT
THWART THE FORECAST WARMING WITH A STRONG SEABREEZE.
BETTER CONFIDENCE FOR THE MONDAY TO THURSDAY FORECAST AS WEAK HIGH
PRESSURE BUILDS IN AND HGTS RISE. OFFSHORE FLOW WILL CONTINUE FROM
THE NORTH AND THE ONSHORE PUSH TO THE EAST WILL WEAKEN (AND MAY
EVEN TURN SLIGHTLY OFFSHORE FOR A FEW HOURS IN THE MORNINGS). THE
MARINE LAYER CLOUDS WILL EITHER BE GREATLY REDUCED OR ELIMINATED
COMPLETELY. 3 TO 6 LOCALLY 8 DEGREES OF WARMING IS FORECAST EACH
DAY FOR MOST OF THE AREA. BY WEDNESDAY THE CSTS WILL SEE HIGHS IN
THE 70S AND EVEN LOWER 80S WITH JUST A FEW BEACHES REMAINING IN
THE 60S. THE VLYS WILL BE IN THE 80S WITH THE WARMEST LOCATIONS
HITTING EITHER 90 OR 91 DEGREES. THESE MAX TEMPS ARE MOSTLY ALL 4
TO 8 DEGREES ABOVE NORMAL.
AVIATION
15/1719Z.
AT 1659Z AT KLAX, THE MARINE INVERSION WAS AROUND 2000 FEET DEEP.
THE TOP OF THE INVERSION WAS 3700 FEET WITH A TEMPERATURE OF 15
DEGREES CELSIUS.
HIGH CONFIDENCE IN TAFS FOR KPRB, KPMD, AND KWJF.
MODERATE CONFIDENCE IN REMAINING TAFS. TIMING OF ARRIVAL OF CIGS
COULD BE +/- 3 HOURS OF CURRENT FORECASTS. MINIMUM FLIGHT CAT MAY
BE OFF BY 1 AT ANY POINT. THERE IS A 20% CHANCE FOR LIFR CONDS AT
KBUR/KVNY. THERE IS A 40% CHANCE FOR VSBYS LESS THAN 1/2SM AT
KSMX/KSBP.
KLAX...MODERATE CONFIDENCE IN TAF. THERE IS A 20% CHANCE FOR IFR
CIGS 008-009 AT SOME POINT TONIGHT. ARRIVAL OF CIGS MAY BE AS
EARLY AS 04Z OR AS LATE AS 10Z. NO SIGNIFICANT EAST WIND
COMPONENT EXPECTED.
KBUR...MODERATE CONFIDENCE IN TAF. THERE IS A 20% CHANCE OF LIFR
CIGS 002-005 AND/OR VSBYS LESS THAN 1SM TONIGHT.
MARINE
15/810 AM.
FOR THE OUTER WATERS, TODAY 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. SEAS WILL BUILD
TO AROUND 15 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 15 FEET DURING THIS TIME. FOR MONDAY, THERE IS A
30-40% 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 THIS AFTERNOON 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, HIGH CONFIDENCE IN
WINDS AND SEAS REMAINING BELOW SCA LEVELS.
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 FROM 3 PM THIS AFTERNOON TO 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/RORKE
AVIATION...LEWIS
MARINE...RAT/LEWIS
SYNOPSIS...MW
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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