928
FXUS66 KLOX 161113
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
413 AM PDT FRI MAY 16 2025
SYNOPSIS
16/412 AM.
STRONG ONSHORE FLOW AND A PERSISTENT MARINE LAYER DEPTH WILL
BRING A COOLING TREND THROUGH THE WEEKEND. GUSTY ONSHORE WINDS ARE
LIKELY, ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS BETWEEN
SATURDAY AND SUNDAY NIGHT ALONG THE COAST AND ACROSS THE INTERIOR
VALLEYS. NIGHT THROUGH MORNING DRIZZLE OR LIGHT RAIN IS POSSIBLE
SATURDAY AND SATURDAY NIGHT. HIGH PRESSURE ALOFT BUILDING IN WILL
BRING A STEADY WARMING TREND THROUGH NEXT WEEK. TEMPERATURES MORE
TYPICAL OF THE SUMMER SEASON ARE LIKELY AWAY FROM THE COAST FOR
THE LATTER HALF OF NEXT WEEK.
SHORT TERM (TDY-SUN)
16/411 AM.
THE LATEST FOG PRODUCT IMAGERY SHOWS A MARINE LAYER LOW CLOUD DECK
BECOMING WELL-ENTRENCHED ACROSS THE REGION THIS MORNING AS AN
EDDY CIRCULATION SPINS UP ACROSS THE SOUTHERN CALIFORNIA BIGHT.
CLOUDS ARE FILLING IN ACROSS THE BIGHT AND MAKING A RUN AT
RETURNING TO THE VALLEYS THIS MORNING.
THE EDDY CIRCULATION WILL LEAD TO STRONGER ONSHORE FLOW ACROSS
THE AREA TODAY AND SATURDAY AND CONTINUE A COOLING TREND INTO
THE WEEKEND. THE MARINE LAYER DEPTH, NEAR 1600 FEET DEEP IN
EARLIER AMDAR SOUNDINGS AT KLAX, WILL LIKELY DEEPEN TO AROUND 2000
FEET DEEP LATER THIS MORNING, THEN START TO DEEPEN SUBSTANTIALLY
THROUGH SATURDAY OR SUNDAY. A WEAK TROUGH WITH A DYING FRONTAL
BOUNDARY OVER ALONG THE NORTH COAST OF CALIFORNIA WILL ADD SOME
DYNAMICS OVER THE COMING NIGHTS AND MORNINGS TO PRODUCE NIGHT
THROUGH MORNING DRIZZLE TONIGHT THROUGH SATURDAY MORNING, AND
AGAIN SATURDAY AND SUNDAY. NAM BUFR TIME HEIGHT SECTIONS SUGGEST
THE MARINE LAYER DEPTH DEEPENING TO NEAR 4500 FEET DEEP AT KLAX
AND 3500 FEET DEEP AT KVBG ON SATURDAY. THIS IS A MORE THAN AMPLE
DEPTH TO PRODUCE NIGHT THROUGH DRIZZLE OR LIGHT SHOWERS ALONG THE
COASTAL SLOPES. MENTIONS OF DRIZZLE REMAIN IN THE FORECAST, BUT
THE POPS WERE INCREASED TO INCREASE THE CHANCES FOR LIGHT RAIN.
WITH THE STRONG ONSHORE FLOW AND A DEEP MARINE LAYER DEPTH,
TEMPERATURES WILL REMAIN ON THE COOL SIDE OF NORMAL. 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 ON
SATURDAY. CLOUDS WILL LIKELY STRUGGLE TO CLEAR THE NEXT SEVERAL
DAYS AND INHIBIT SOLAR INSOLATION.
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
16/1101Z.
AT 0945Z AT KLAX, THE MARINE INVERSION WAS AROUND 900 FEET DEEP.
THE TOP OF THE INVERSION WAS 4000 FEET WITH A TEMPERATURE OF
16 DEGREES CELSIUS.
OVERALL, HIGH CONFIDENCE IN 12Z TAFS FOR KPRB...KWJF AND KPMD.
FOR ALL OTHER SITES, MODERATE CONFIDENCE IN 12Z TAFS. TIMING OF
DISSIPATION OF MVFR TO LIFR CONDITIONS COULD BE +/- 2 HOURS OF
CURRENT FORECASTS. FOR TONIGHT, HIGH CONFIDENCE IN RETURN OF CIG
AND VSBY RESTRICTIONS, BUT MODERATE CONFIDENCE IN TIMING (COULD
BE +/- 2 HOURS OF CURRENT FORECASTS).
KLAX...MODERATE CONFIDENCE IN 12Z TAF. TIMING OF DISSIPATION OF
MVFR CIGS COULD BE +/- 2 HOURS OF CURRENT 21Z FORECAST. FOR
TONIGHT, TIMING OF RETURN OF MVFR CIGS COULD BE +/- 2 HOURS OF
CURRENT 02Z FORECAST. NO SIGNIFICANT EASTERLY WIND COMPONENT IS
EXPECTED.
KBUR...MODERATE CONFIDENCE IN 12Z TAF. TIMING OF DISSIPATION OF
IFR CIGS COULD BE +/- 2 HOURS OF CURRENT 18Z FORECAST. FOR
TONIGHT, TIMING OF RETURN OF MVFR CIGS COULD BE +/- 2 HOURS OF
CURRENT 07Z FORECAST (WITH A 40% CHANCE OF CIGS DEVELOPING AT IFR
LEVELS).
MARINE
16/401 AM.
FOR THE OUTER WATERS, MODERATE TO HIGH 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.
FOR THE INNER WATERS, MODERATE TO HIGH 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 TO HIGH
CONFIDENCE IN CURRENT FORECAST. TODAY THROUGH TONIGHT, HIGH
CONFIDENCE IN WINDS AND SEAS REMAINING BELOW SCA LEVELS. FOR
SATURDAY THROUGH SUNDAY NIGHT, HIGH CONFIDENCE IN SCA LEVEL WINDS,
MAINLY ACROSS WESTERN SECTIONS OF THE SOUTHERN INNER WATERS.
ADDITIONALLY, THERE IS A 50% CHANCE OF GALE FORCE WINDS ACROSS THE
WESTERN HALF OF THE SANTA BARBARA CHANNEL SATURDAY EVENING THROUGH
SATURDAY NIGHT. FOR MONDAY THROUGH TUESDAY, HIGH CONFIDENCE IN
WINDS AND SEAS REMAINING BELOW SCA LEVELS.
LOX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
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...HALL
AVIATION...RAT
MARINE...RAT
SYNOPSIS...HALL
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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