910
FXUS66 KLOX 041006
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
306 AM PDT THU SEP 4 2025
SYNOPSIS
04/221 AM.
A SLIGHT COOLING TREND WILL KNOCK A FEW DEGREES OFF THE DAYTIME
HIGHS THROUGH THE WEEKEND, BRINGING TEMPERATURES BACK TO NEAR
NORMAL LEVELS. THEN NEXT WEEK A LOW PRESSURE SYSTEM WILL ENCOMPASS
THE ENTIRE WEST COAST BRINGING TEMPERATURES DOWN TO 6 TO 12
DEGREES BELOW NORMAL. MONSOON MOISTURE IS NOT EXPECTED TO RETURN
FOR AT LEAST THE NEXT WEEK.
SHORT TERM (TDY-SAT)
04/242 AM.
WEAKENING HIGH PRESSURE WILL CONTINUE THROUGH THE WEEKEND AS THE
PATTERN MAKES A SIGNIFICANT SHIFT FROM HOT AND HUMID CONDITIONS
TO MUCH COOLER AND LESS HUMID WEATHER NEXT WEEK. IN THE MEANTIME,
STILL EXPECTING MOST AREAS TO BE 1-4 DEGREES ABOVE NORMAL
THU/FRI WITH STILL ABOVE NORMAL HUMIDITY. THE NXK SOUNDING
YESTERDAY AFTERNOON SHOWED A MARKED DROP IN PW'S FROM THE LAST FEW
DAYS, DROPPING A HALF INCH FROM WEDNESDAY. THIS LIKELY WAS A
SIGNIFICANT REASON WHY THERE WAS MINIMAL AFTERNOON CONVECTION
ACROSS THE MOUNTAINS, AND EXPECTING SIMILAR IF NOT EVEN LESS
CUMULUS DEVELOPMENT TODAY. WE ARE SEEING A SLIGHT UPTICK IN
STRATUS ACROSS COASTAL LA/VENTURA COUNTIES THIS MORNING, AND EVEN
SNEAKING INTO THE SOUTHERN SALINAS VALLEY, AND WITH HIGH PRESSURE
CONTINUING TO WEAKEN OVER THE WEEKEND AND ONSHORE FLOW INCREASING,
LOW CLOUD COVERAGE IS EXPECTED TO EXPAND ACROSS MORE COASTAL
AREAS AND SOME OF THE VALLEYS.
LONG TERM (SUN-WED)
04/305 AM.
SUNDAY WILL LOOK AND FEEL A LOT LIKE SATURDAY, THOUGH THERE
REMAINS SEVERAL ENSEMBLE SOLUTIONS FAVORING A MINOR WARM UP OF
1-3 DEGREES AS HEIGHTS RISE SLIGHTLY IN RESPONSE TO THE PACNW
UPPER CONTINUING TO DROP SOUTH ALONG 140W. FOR THE MOST PART THIS
WILL JUST BE A MINOR DEVIATION IN WHAT IS EXPECTED TO BE THE
BEGINNING OF A LENGTHY COOLING TREND THAT WILL LAST THE REMAINDER
OF NEXT WEEK AS THAT UPPER LOW TAKES UP CAMP ALONG THE WEST COAST.
BY THE LATTER HALF OF THE WEEK THE UPPER LOW IS EXPECTED TO SIT
RIGHT ALONG THE NORTHERN CALIFORNIA COAST WITH 500MB HEIGHTS DOWN
TO AROUND 570DAM. THIS WILL PRODUCE A HEFTY DOSE OF ONSHORE FLOW
AND MARINE LAYER STRATUS THAT WILL MOST LIKELY PUSH WELL INTO THE
VALLEYS AND KEEP TEMPERATURES 6-12 DEGREES BELOW NORMAL. WOULD NOT
EVEN BE SURPRISED IF WE GET SOME COAST/VALLEY DRIZZLE AT TIMES AS
WELL WITH ONLY LIMITED CLEARING ALONG SOME OF THE BEACHES. GIVEN
THE STRONG SOUTHWEST FLOW ALOFT, MONSOON MOISTURE WILL BE PUSHED
OUT OF CALIFORNIA SO NO AFTERNOON CONVECTION IS EXPECTED NEXT
WEEK.
AVIATION
04/1003Z.
DUE TO A NATIONAL METAR OUTAGE, THERE WILL BE LIMITED OR NO
AMENDMENTS UNTIL OBSERVATIONS ARE RESTORED.
AROUND 0715Z, THE MARINE LAYER DEPTH WAS NEAR 900 FEET DEEP AT
KLAX. THE TOP OF THE MARINE INVERSION WAS AROUND 1700 FEET WITH A
TEMPERATURE NEAR 26 DEGREES CELSIUS. THERE WAS ANOTHER INVERSION
UP TO AROUND 2700 FEET.
HIGH CONFIDENCE IN THE CURRENT FORECAST FOR VALLEY AND DESERT
TERMINALS EXCEPT KPRB WHERE MODERATE CONFIDENCE EXISTS THROUGH
16Z. MODERATE CONFIDENCE EXISTS IN THE CURRENT FORECAST FOR
COASTAL TERMINALS THROUGH 16Z, AND AGAIN AFTER 03Z FRIDAY. THERE
IS A MODERATE TO HIGH CHANCE OF LIFR TO IFR CONDITIONS AT COASTAL
TERMINALS THROUGH 16Z, AND AGAIN AFTER 03Z TONIGHT. THERE IS A LOW
CHANCE OF SHOWERS AND THUNDERSTORMS AT DESERT TERMINALS BETWEEN
20Z AND 02Z.
KLAX...THERE IS A 30 PERCENT CHANCE OF IFR CONDITIONS THROUGH 16Z,
OTHERWISE VFR CONDITIONS WILL LIKELY PERSIST. ANY EASTERLY WINDS
WILL VERY LIKELY REMAIN LESS THAN 7 KNOTS.
KBUR...VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. NO WIND
IMPACTS ARE EXPECTED AT THIS TIME.
MARINE
03/834 PM.
MODERATE TO HIGH CONFIDENCE IN CURRENT FORECAST.
FOR THE OUTER WATERS, SMALL CRAFT ADVISORY (SCA) WINDS WILL BE
PRESENT ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS THROUGH
THE WEEKEND. SEAS WILL PEAK AROUND 7 FEET THURSDAY INTO FRIDAY,
BECOMING SMALL OVER THE WEEKEND.
FOR THE INNER WATERS ALONG THE CENTRAL COAST, MODERATE CHANCES
EACH DAY DURING THE AFTERNOON & EVENING TIMEFRAME FOR SCA LEVEL
WIND GUSTS ESPECIALLY ACROSS NW PORTIONS AND NEARSHORE PORT SAN
LUIS THROUGH THE WEEKEND.
INSIDE THE SOUTHERN CALIFORNIA BIGHT, THERE IS A MODERATE CHANCE
OF SCA LEVEL WINDS THURSDAY THROUGH SATURDAY AFTERNOON AND
EVENING - ESPECIALLY ACROSS WESTERN/SOUTHERN PORTIONS OF THE
SANTA BARBARA CHANNEL, NEAR POINT DUME, & INTO THE SAN PEDRO
CHANNEL. BY SUNDAY, CHANCES FOR SCA LEVEL WINDS IN THE SANTA
BARBARA CHANNEL INCREASE AS WIND SPEEDS AND SPATIAL COVERAGE
INCREASE. SEAS WILL REMAIN SMALL, BUT WILL BEGIN TO INCREASE
SUNDAY AND MONDAY ACROSS THE SANTA BARBARA CHANNEL.
LOX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT FROM NOON TODAY TO 9 PM PDT
THIS EVENING FOR ZONE 645. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT FROM NOON TODAY TO 3 AM PDT
SATURDAY FOR ZONE 670. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PDT SATURDAY FOR
ZONES 673-676. (SEE LAXMWWLOX).
PUBLIC...MW
AVIATION...HALL
MARINE...BLACK/LEWIS
SYNOPSIS...MW
WEATHER.GOV/LOSANGELES
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