055
FXUS66 KLOX 311159
AFDLOX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
459 AM PDT SUN AUG 31 2025
SYNOPSIS
31/357 AM.
A HOT AIR MASS WILL CONTINUE OVER THE REGION THROUGH MUCH OF THE
WEEK AS HIGH PRESSURE ALOFT WILL REMAIN ANCHORED NEAR THE FOUR
CORNERS REGION. MONSOONAL MOISTURE WILL ARRIVE AGAIN ON TUESDAY
AND KEEP A LOW BUT PRESENT RISK OF SHOWERS AND THUNDERSTORMS
THROUGH THE REMAINDER OF THE WEEK. A COOLING TREND IS POSSIBLE FOR
THE UPCOMING WEEKEND.
SHORT TERM (TDY-TUE)
31/356 AM.
THE LATEST WATER VAPOR IMAGERY SHOWS AN UPPER-LEVEL RIDGE OF HIGH
PRESSURE CENTERED OVER SOUTH TEXAS THIS MORNING. THIS RIDGE WILL
EXPAND AND BUILD INTO FOUR CORNERS REGION TODAY AND REMAIN IN
PLACE THROUGH MUCH OF THE WEEK. A WARMING TREND WILL CONTINUE
THROUGH TUESDAY AS 500 MB HEIGHTS CLIMB A BIT EACH DAY. HEAT RISK
VALUES ARE STARTING TO TICK A LITTLE HIGHER AND ARE MARGINAL
ENOUGH TO EXTEND HEAT ADVISORIES ACROSS THE SOUTHLAND TO START
LATER THIS MORNING RATHER THAN MONDAY MORNING. HEAT ADVISORIES
WERE ALSO EXPANDED INTO THE INTERIOR COASTAL SECTIONS OF THE
VENTURA COUNTY COASTAL PLAIN FROM 10 AM THIS MORNING TO 6 PM THIS
EVENING.
TO THE NORTH, HEAT ADVISORIES WILL GO INTO EFFECT LATER THIS
MORNING AS WEAK OFFSHORE FLOW DEVELOPS. BREEZY SANTA LUCIA WINDS
ARE ALREADY IN PLACE THIS MORNING WITH GUSTS BETWEEN 25 AND 30 MPH
BEING RECORDED THIS MORNING. TEMPERATURES WILL WARM TO NEAR
DANGEROUS LEVELS TODAY. SOME FOOTHILLS AND MOUNTAIN STATIONS
INDICATE OVERNIGHT LOW TEMPERATURES ONLY FALLING INTO THE MID TO
UPPER 70S AND LOWER 80S, SO FAR.
WHILE SOME HEAT ADVISORY HEADLINES EXTEND INTO TUESDAY, THERE IS
A CHANCE THAT MONSOONAL MOISTURE COULD SLIP IN ON TUESDAY. THE
LATEST DETERMINISTIC SOLUTIONS AGREE WELL WITH GEFS ENSEMBLE
MEMBERS TO BRING A CLOUDIER PATTERN ACROSS THE REGION ON TUESDAY
WITH SHOWERS CHANCES ENTERING THE FORECAST. THIS COULD END UP
CUTTING INTO TEMPERATURES AND BRING THE THREAT OF SHOWERS AND
ISOLATED THUNDERSTORMS TO MOST AREAS SOUTH OF POINT CONCEPTION.
MUCH WILL DEPEND HOW MUCH CLOUD COVERAGE DEVELOPS AND HOW MUCH
MOISTURE SPILLS INTO THE REGION ON TUESDAY.
LONG TERM (WED-SAT)
31/354 AM.
HIGH PRESSURE ALOFT, ALBEIT WEAKER, WILL LINGER OVER THE
SOUTHWESTERN UNITED STATES INTO WEDNESDAY AND THURSDAY. A VERY
WARM AIR MASS WITH ADDED HUMIDITY FROM THE DESERT MONSOON IS
LIKELY TO PERSIST. TEMPERATURES ABOVE SEASONAL NORMALS SHOULD BE
EXPECTED INTO AT LEAST THURSDAY. THERE IS A MODERATE CHANCE THAT
HEAT HEADLINES MAY BE EXTENDED INTO WEDNESDAY OR THURSDAY. WITH
THE INCREASED MONSOON MOISTURE AND OVERALL HOT AIR MASS IN PLACE,
TUESDAY NIGHT MAY END UP BEING THE WARMEST NIGHT OF THE WEEK,
GIVING DAYTIME HEATING A HEAD START FOR WEDNESDAY. OVERNIGHT LOW
TEMPERATURES ACROSS MUCH OF THE LA METRO AREA COULD REMAIN ABOVE
70 DEGREES, WHILE MANY FOOTHILL AND MOUNTAIN AREAS MAY SEE
OVERNIGHT LOW TEMPERATURES IN THE MID 70S TO LOWER 80S, ADDING TO
THE HEAT RISK.
A COOLING TREND SHOULD DEVELOP ON FRIDAY AND INTO NEXT WEEKEND.
THE LATEST ENSEMBLE MEMBERS SHOWS 500 MB HEIGHT MEANS TRENDING
DOWNWARD THROUGH MUCH OF NEXT WEEKEND.
SOUTHEAST FLOW ALOFT WILL LIKELY BE IN PLACE BETWEEN TUESDAY AND
FRIDAY. THE AREA WILL SIT ON THE WESTERN EDGE OF THE MONSOON, AND
THERE WILL LIKELY BE SHOWER AND THUNDERSTORMS CHANCES IN THE
FORECAST EACH DAY. THE HIGHEST CHANCES OF SHOWERS AND
THUNDERSTORMS WILL LIKELY PERSIST ACROSS THE SAN GABRIEL
MOUNTAINS AND ANTELOPE VALLEY, BUT THERE IS A CHANCE THAT AN
EASTERLY WAVE COULD PUSH UNDERNEATH THE RIDGE INTO SOUTHERN
CALIFORNIA. CHANCES FOR SHOWERS AND THUNDERSTORMS CANNOT BE RULED
OUT ENTIRELY DURING THE LONG TERM PERIOD.
AVIATION
31/1158Z.
AROUND 12Z AT KLAX, THE MARINE LAYER WAS 500 FT DEEP. THE TOP OF
THE INVERSION WAS AT 2800 FT WITH A TEMPERATURE OF 29 C.
LOW CONFIDENCE IN TAFS FOR KOXR, KCMA, KSMO, KLAX, AND KLGB DUE
TO UNCERTAINTY OF LOW CLOUDS. TIMING OF FLIGHT CAT CHANGES MAY BE
OFF +/- 3 HOURS AND MINIMUM CIG HEIGHTS MAY BE OFF +/- 300 FEET.
CIGS MAY SCATTER AND REFORM FREQUENTLY THROUGH 17Z. THERE IS A
10-30% CHANCE FOR VSBYS LESS THAN 1SM, HIGHEST CHANCES AT KOXR AND
KCMA.
HIGH CONFIDENCE IN REMAINING TAFS.
KLAX...LOW CONFIDENCE IN TAF UNTIL 20Z, HIGH CONFIDENCE FROM 20Z
SUN TO 03Z MON, THEN MODERATE CONFIDENCE. CIGS MAY SCATTER AND
REFORM FREQUENTLY THROUGH 17Z, WITH A 40% CHANCE OF NO LOW CLOUDS.
IF LOW CLOUDS DO ARRIVE, THERE IS A 15% CHANCE FOR VSBYS
1/2SM-1SM AT TIMES DUE TO SHALLOW MARINE LAYER. TIMING OF FLIGHT
CAT CHANGES MAY BE OFF +/- 3 HOURS AND MINIMUM CIG HEIGHT MAY BE
OFF 300 FEET. GOOD CONFIDENCE THAT ANY EAST WIND COMPONENT WILL
REMAIN BELOW 7 KT.
KBUR...HIGH CONFIDENCE IN TAF.
MARINE
31/241 AM.
HIGH CONFIDENCE IN 20-30 KT NW WINDS ACROSS THE OUTER WATERS FROM
POINT SAL NORTH TO POINT PIEDRAS BLANCAS CONTINUING THROUGH LABOR
DAY (MONDAY), WITH MODERATE CONFIDENCE IN LOCAL GUSTS UP TO 35 KT
DURING THE AFTERNOON AND EVENING HOURS TODAY. MODERATE CONFIDENCE
IN THE REMAINING OUTER WATERS REMAINING BELOW SMALL CRAFT
ADVISORY (SCA) CRITERIA THROUGH THIS MORNING, WITH A 30% CHANCE OF
WINDS INCREASING TO SCA LEVELS DURING THE AFTERNOON AND EVENING
HOURS TODAY AND MONDAY. TUESDAY INTO THURSDAY, THE BEST CHANCES
FOR SCA WINDS ARE FOCUSED AROUND POINT CONCEPTION SOUTH TO SAN
NICOLAS ISLAND. A RELATIVE LULL IN WINDS WILL BE LIKELY EACH
MORNING.
MODERATE CONFIDENCE IN FORECAST FOR THE NEARSHORE WATERS ALONG
THE CENTRAL COAST, WITH A 30% CHANCE OF SCA CONDS IN THE
AFTERNOON AND EVENINGS TODAY AND MONDAY, THEN LIGHTER WINDS AND
SMALLER SEAS LIKELY.
ASIDE FROM FAIRLY SEASONAL AFTERNOON AND EVENING LOCALIZED NW
WIND GUSTS 20-25 KTS IN THE FAR WESTERN PORTION OF THE SANTA
BARBARA CHANNEL AND 15-20 KTS IN THE SAN PEDRO CHANNEL, LIGHT
WINDS AND SMALL SEAS WILL BE COMMON FOR THE NEARSHORE WATERS SOUTH
OF POINT CONCEPTION THROUGH LABOR DAY. BETTER CHANCES FOR MORE
WIDESPREAD SCA WINDS ON TUESDAY THROUGH THURSDAY DURING THE
AFTERNOON AND EVENINGS.
LOX WATCHES/WARNINGS/ADVISORIES
CA...HEAT ADVISORY REMAINS IN EFFECT FROM 10 AM THIS MORNING TO 6
PM PDT TUESDAY FOR ZONES 38-344-345-353. (SEE LAXNPWLOX).
HEAT ADVISORY IN EFFECT FROM 10 AM THIS MORNING TO 10 AM PDT
MONDAY FOR ZONES 88-352-356>358-369>375. (SEE LAXNPWLOX).
HEAT ADVISORY NOW IN EFFECT FROM 10 AM MONDAY TO 6 PM PDT
TUESDAY FOR ZONES 88-356>358-368>376-378-379-548. (SEE LAXNPWLOX).
BEACH HAZARDS STATEMENT IN EFFECT THROUGH MONDAY EVENING FOR
ZONES 340-346-354-362-366. (SEE LAXCFWLOX).
HEAT ADVISORY REMAINS IN EFFECT FROM 10 AM THIS MORNING TO 6
PM PDT THIS EVENING FOR ZONES 341>343-347>349-351. (SEE LAXNPWLOX).
HEAT ADVISORY IN EFFECT FROM 10 AM THIS MORNING TO 6 PM PDT
THIS EVENING FOR ZONE 355. (SEE LAXNPWLOX).
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PDT MONDAY FOR ZONE
670. (SEE LAXMWWLOX).
PUBLIC...HALL
AVIATION...LUND
MARINE...LEWIS/LUND
SYNOPSIS...HALL
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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