023
FXUS66 KLOX 161746
AFDLOX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1046 AM PDT FRI MAY 16 2025
UPDATED AVIATION SECTION
SYNOPSIS
16/923 AM.
STRONG ONSHORE FLOW AND A DEEP MARINE LAYER WILL BRING COOL
WEATHER THROUGH SATURDAY. GUSTY ONSHORE WINDS ARE EXPECTED IN THE
ANTELOPE VALLEY DURING THE AFTERNOON AND EVENING. NIGHT THROUGH
MORNING DRIZZLE OR LIGHT RAIN IS POSSIBLE SATURDAY. A WARMING
TREND WILL BE WILL BEGIN SUNDAY AND CONTINUE THROUGH NEXT WEEK AS
HIGH PRESSURE DEVELOPS. TEMPERATURES MORE TYPICAL OF THE SUMMER
SEASON ARE LIKELY AWAY FROM THE COAST FOR THE LATTER HALF OF NEXT
WEEK.
SHORT TERM (TDY-SUN)
16/933 AM.
***UPDATE***
THE MARINE LAYER HAS DEEPENED TO AROUND 3000 FEET THIS MORNING IN
RESPONSE TO THE NEXT UPPER LEVEL TROUGH APPROACHING THE WEST
COAST. ONSHORE FLOW IS TRENDING STRONGLY ONSHORE TODAY AND THAT
WILL CONTINUE INTO SATURDAY. TEMPERATURES ARE ALREADY TRENDING
COOLER THIS MORNING ACROSS COAST AND VALLEYS, IN SOME AREAS BY AS
MUCH AS 10 DEGREES. OVERALL, MOST AREAS WILL END UP 3-6 DEGREES
COOLER THAN YESTERDAY, WITH THE MARINE LAYER ONLY SLOWLY CLEARING
THROUGH THE MORNING AND EARLY AFTERNOON.
***FROM PREVIOUS DISCUSSION***
SATURDAY, WHEN THE MARINE INFLUENCE LOOKS TO BE GREATEST, LOOKS
TO THE BE THE COOLEST DAY OF THE PERIOD. TEMPERATURES AROUND THE
60S TO LOWER 70S WILL BE COMMON ACROSS THE COASTAL AND VALLEY
AREAS AND CLOUDS WILL LIKELY STRUGGLE TO CLEAR AND THERE MAY BE
SOME AREAS OF DRIZZLE.
GUSTY ONSHORE WINDS WILL DEVELOP BETWEEN SATURDAY AND SUNDAY
NIGHT DUE TO STRONG ONSHORE PRESSURE GRADIENTS. ADVISORY LEVEL
WINDS ARE LIKELY ALONG THE COASTAL AREAS AND ACROSS THE INTERIOR
VALLEYS, ESPECIALLY EACH AFTERNOON AND EVENING. THE DYING FRONTAL
BOUNDARY WILL SLIDE SOUTH OVER THE AREA ON SATURDAY AND THE
PATTERN WILL SHIFT THE WIND FROM SOUTHWEST TO WEST ON SATURDAY TO
WEST TO NORTHWEST BETWEEN SATURDAY NIGHT AND INTO SUNDAY. WIND
ADVISORIES WILL LIKELY BE NEEDED FOR MOST COASTAL AREAS AND THE
ANTELOPE VALLEY ON SATURDAY AND SUNDAY, AND THROUGH THE INTERSTATE
5 CORRIDOR AND ACROSS SOUTHERN SANTA BARBARA COUNTY ON SATURDAY
NIGHT AND INTO SUNDAY.
THE NORTHERLY PRESSURE GRADIENT WILL LIKELY TIGHTEN AGAIN ON
SUNDAY NIGHT INTO MONDAY. THERE IS A LOW-TO-MODERATE CHANCE OF
WARNING LEVEL WINDS DEVELOPING THROUGH THE INTERSTATE 5 CORRIDOR
AND ACROSS SOUTHERN SANTA BARBARA COUNTY. A FEW SOLUTIONS OF THE
EPS MEMBERS INDICATE WARNING LEVEL GUSTS AT KSDB, WHILE THE
LATEST NAM-WRF SOLUTIONS INDICATE 45-50 KNOTS OF WIND AT 850 MB
ACROSS THE TRANSVERSE RANGES ON SUNDAY NIGHT. FURTHER HINTING AT
THE POSSIBILITY, ECMWF EFI VALUES HIGHLIGHT THE TRANSVERSE RANGES
ON SUNDAY NIGHT, WHILE NAEFS STANDARDIZED ANOMALIES NOSING
850-700 MB WINDS BETWEEN 3 AND 4 STANDARD DEVIATION VERSUS THE
CFSR PERIOD OVER THE CENTRAL COAST. WIND ADVISORIES ARE LIKELY TO
BE ISSUED FOR SUNDAY NIGHT WHEN THE TIMING AND FINER DETAILS COME
TOGETHER, BUT THE HIGH WIND WARNING POTENTIAL WILL NEED TO BE
WATCHED CLOSELY.
LONG TERM (MON-THU)
16/405 AM.
GUSTY NORTHERLY WINDS ARE LIKELY TO PERSIST INTO MONDAY MORNING AS
THE SURFACE PRESSURE GRADIENTS REMAIN TIGHT.
CONFIDENCE REMAINS HIGH FOR A WARMING TREND FOR NEXT WEEK AS HIGH
PRESSURE ALOFT WILL BUILD IN OVER THE REGION. WHILE THERE IS SOME
UNCERTAINTY FOR MONDAY, EPS 500 MB HEIGHT MEANS CLIMB THROUGH AT
LEAST THURSDAY. BY WEDNESDAY OR THURSDAY, EPS HIGH TEMPERATURE
MEANS SUGGEST VALUES IN THE 90S BEING COMMON FOR THE VALLEYS,
FOOTHILLS, AND DESERT, WHILE TEMPERATURES IN THE 80S TO LOWER 90S
COULD BE COMMON ACROSS THE COAST. DETERMINISTIC ECMWF SOLUTIONS
SUPPORT THE IDEA OF WARMING AS PRESSURE GRADIENTS WEAKEN
SUBSTANTIALLY TO NEAR NEUTRAL OR LIGHT OFFSHORE. NBM SOLUTIONS
GIVE ABOUT A 15 PERCENT CHANCE OF KPMD AND KWJF OF HITTING 100
DEGREES, WHICH IF IT OCCURRED WOULD BE ABOUT THREE WEEKS EARLIER
THAN NORMAL. AWAY FROM THE COAST, THE TEMPERATURE FORECAST LEANS
MORE HEAVILY INTO THE 75TH PERCENTILE OF NBM SOLUTIONS BETWEEN THE
PERIOD BETWEEN WEDNESDAY AND THURSDAY NIGHT. EXPERIMENTAL NWS
HEAT RISK VALUES CLIMB FOR WEDNESDAY AND THURSDAY, TRENDING TOWARD
A PERIOD POTENTIALLY DANGEROUS HEAT.
AVIATION
16/1746Z.
AT 1640Z AT KLAX, THE MARINE INVERSION WAS AROUND 3000 FEET DEEP.
THE TOP OF THE INVERSION WAS 4500 FEET WITH A TEMPERATURE OF 14
DEGREES CELSIUS.
HIGH CONFIDENCE IN TAFS FOR KWJF AND KPMD.
MODERATE CONFIDENCE IN TAFS FOR REMAINING SITES. THERE IS A 30%
CHANCE FOR IFR TO MVFR CIGS BETWEEN 12Z AND 18Z AT KPRB. COASTAL
SITES FORECAST TO CLEAR HAVE A 30% CHANCE OF NOT CLEARING, AND 30%
CHANCE FOR SITES FORECAST TO NOT CLEAR TO SCT. DISSIPATION OF CIGS
MAY BE OFF +/- 2 HOURS, AND ARRIVAL MAY BE OFF +/- 3 HOURS.
MINIMUM FLIGHT CAT MAY BE OFF BY ONE CAT FOR KSBP/KSMX.
KLAX...MODERATE CONFIDENCE IN TAF. THERE IS A 30% CHANCE FOR CIGS
TO SCT BETWEEN 20Z AND 03Z. CIGS MAY SCT TOMORROW BETWEEN 20Z AND
00Z. THERE IS A 20-40% CHANCE FOR AN EAST WIND COMPONENT OF 8 KTS
BETWEEN 11Z AND 18Z. BEST CHANCES BETWEEN 14Z AND 18Z.
KBUR...MODERATE CONFIDENCE IN TAF. RETURN OF CIGS MAY BE OFF +/- 3
HOURS, AND THERE IS A 20% CHANCE FOR CIGS 007-009.
MARINE
16/806 AM.
FOR THE OUTER WATERS, MODERATE CONFIDENCE IN CURRENT FORECAST.
TODAY THROUGH TUESDAY, HIGH CONFIDENCE IN COMBINATION OF SMALL
CRAFT ADVISORY (SCA) LEVEL WINDS AND SEAS. FOR SATURDAY AFTERNOON
THROUGH SUNDAY NIGHT, THERE IS A 50-60% CHANCE OF GALE FORCE
WINDS, WITH HIGHER CHANCES SUNDAY AFTERNOON THROUGH LATE NIGHT.
FOR THE INNER WATERS, MODERATE CONFIDENCE IN CURRENT FORECAST.
TODAY THROUGH SUNDAY NIGHT, HIGH CONFIDENCE IN SCA LEVEL WINDS,
ESPECIALLY IN THE AFTERNOON AND EVENING HOURS. THERE IS A 50%
CHANCE OF GALE FORCE WINDS SATURDAY AFTERNOON THROUGH SUNDAY
EVENING. FOR MONDAY THROUGH TUESDAY, THERE IS A 50-70% CHANCE OF
SCA LEVEL WINDS CONTINUING.
FOR THE INNER WATERS SOUTH OF POINT CONCEPTION, MODERATE
CONFIDENCE IN CURRENT FORECAST. THROUGH SATURDAY MORNING, HIGH
CONFIDENCE IN WINDS AND SEAS REMAINING BELOW SCA LEVELS. FOR
SATURDAY THROUGH SUNDAY NIGHT, HIGH CONFIDENCE IN SCA LEVEL
WINDS, FOCUS THROUGH THE SANTA BARBARA AND WESTERN SECTIONS OF THE
SOUTHERN INNER WATERS. ADDITIONALLY, THERE IS A 50% CHANCE OF
GALE FORCE WINDS ACROSS THE SANTA BARBARA CHANNEL SATURDAY EVENING
THROUGH SATURDAY NIGHT, WITH A 30% CHANCE SUNDAY AFTERNOON
THROUGH LATE NIGHT. FOR MONDAY THROUGH TUESDAY, HIGH CONFIDENCE IN
WINDS AND SEAS REMAINING BELOW SCA LEVELS.
LOX WATCHES/WARNINGS/ADVISORIES
CA...WIND ADVISORY IN EFFECT FROM 10 AM TO 9 PM PDT SATURDAY FOR
ZONES 381-383. (SEE LAXNPWLOX).
PZ...SMALL CRAFT ADVISORY IN EFFECT FROM 3 PM THIS AFTERNOON TO 9
PM PDT THIS EVENING FOR ZONE 645. (SEE LAXMWWLOX).
GALE WATCH IN EFFECT FROM SATURDAY AFTERNOON THROUGH LATE
SATURDAY NIGHT FOR ZONES 645-670-673-676. (SEE LAXMWWLOX).
GALE WATCH IN EFFECT FROM SATURDAY EVENING THROUGH LATE
SATURDAY NIGHT FOR ZONE 650. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 2 PM PDT SATURDAY FOR
ZONES 670-673-676. (SEE LAXMWWLOX).
PUBLIC...MW/HALL
AVIATION...LEWIS
MARINE...RAT/LEWIS
SYNOPSIS...MW/HALL
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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