112
FXUS66 KLOX 200959
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
259 AM PDT MON OCT 20 2025
SYNOPSIS
19/1154 PM.
DRY AND UNEVENTFUL WEATHER WILL OCCUR TODAY AND TUESDAY WITH HIGH
TEMPERATURES A LITTLE BELOW NORMAL ACROSS THE COASTS AND VALLEYS
AND A LITTLE ABOVE NORMAL ACROSS THE INTERIOR. A DEEP MARINE
LAYER WILL BRING CLOUDS AND SOME DRIZZLE TO ALL OF THE COASTS AND
VALLEYS ON WEDNESDAY. MAX TEMPERATURES ON WEDNESDAY WILL FALL
DRAMATICALLY WITH HIGHS ONLY IN THE MID 60S TO LOWER 70S ACROSS
ALL OF THE COASTS AND VLYS. DRY AND WARMER CONDITIONS ARE SLATED
FOR THE END OF THE WEEK.
SHORT TERM (TDY-WED)
20/258 AM.
PRETTY BORING WEATHER DAY TODAY. SRN CA IS UNDER A WEAK RIDGE WITH
587 DAM HGTS OVERHEAD. TO THE SW A LARGE DRY UPPER LOW IS SPINNING
AND NOT MOVING MUCH. NEAR NEUTRAL FLOW AT THE SFC HAS NOT ALLOW
MUCH IN THE WAY OF MARINE LAYER FORMATION OR PENETRATION. THE HIGH
HGTS HAVE SMOOSHED THE MARINE LAYER LOW ENOUGH TO CREATE POCKETS
OF DENSE FOG ACROSS THE CENTRAL COAST AND THE SANTA YNEZ VLY WHERE
A DENSE FOG ADVISORY IS IN EFFECT UNTIL 900 AM. OTHERWISE IT WILL
BE SUNNY DAY WITH COOLER CONDITIONS AT THE COAST DUE TO WEAKER
OFFSHORE.
NOT MUCH CHANGE ON TUESDAY THE UPPER LOW WILL NUDGE A LITTLE
CLOSER AS IT BEGINS ITS TREK TO THE NE. THERE WILL BE A LITTLE
MORE ONSHORE FLOW AND THIS SHOULD RESULT IN A LITTLE MORE MARINE
LAYER STRATUS ACROSS THE COASTS. THE INCREASED ONSHORE FLOW WILL
BRING 2 TO 4 DEGREES OF COOLING TO THE CSTS/VLYS WHILE THE
INTERIOR SEES LITTLE CHANGE IN TEMPERATURES.
ON TUESDAY NIGHT AND WEDNESDAY THE UPPER LOW TO THE SW WILL MOVE
TO THE NW AND WILL MOVE OVER THE AREA. THE LOWERING HGTS AND LIFT
FROM THE LOWS APPROACH WILL QUICKLY DEEPEN THE MARINE LAYER. IT
WILL LIKELY DEEPEN TO AROUND 5000 FT. THIS WILL BRING LOW CLOUDS
TO ALL OF THE CSTS AND VLYS AS WELL AS THE COASTAL SLOPES AND SOME
MTN PASSES. THE RAPID DEEPENING WILL ALSO LIKELY BRING SOME
DRIZZLE OR EVEN LIGHT RAIN TO THE CSTS/VLYS ESP AREAS NEAR THE
FOOTHILLS. THERE IS A NON ZERO CHANCE OF SOME MTN CONVECTION IN
THE LATE MORNING OR AFTERNOON BUT THE EXACT CHC DEPENDS ON THE
TRACK AND TIMING OF THE LOW'S PASSAGE. WILL KEEP CONVECTION OUT OF
THE FCST FOR NOW AND WILL WAIT FOR THE HI REZ MDL WINDOW TO OPEN
UP. ONE THING IS FOR CERTAIN - THE FALLING HGTS AND CLOUDS WILL
BRING 2 TO 4 DEGREES OF COOLING TO THE CSTS; 5 TO 10 DEGREES FOR
THE VLYS; AND 8 TO 12 DEGREES FOR THE MTNS AND INTERIOR. MAX TEMPS
WILL END UP 5 TO 10 DEGREES BLO NORMAL WITH ONLY UPPER 60S TO MID
70S FOR HIGHS ACROSS THE CSTS/VLYS.
LONG TERM (THU-SUN)
20/1228 AM.
TWO DAYS OF DRY LOW IMPACT WEATHER ON THURSDAY AND FRIDAY. A WEAK
RIDGE WILL NOSE INTO SRN CA FROM THE WEST AND HGTS WILL BUMP UP TO
ABOUT 584 DAM. AT THE SFC THERE WILL BE WEAK ONSHORE FLOW TO THE
EAST AND WEAK OFFSHORE FLOW FROM THE NORTH. NIGHT THROUGH MORNING
LOW CLOUDS WILL LIKELY AFFECT MOST OF THE COASTS, BUT ONLY THE
LOWER VLYS. THE RISING HGTS AND INCREASED SUNSHINE WILL LEAD TO 3
TO 6 LOCALLY 8 DEGREES OF WARMING ON THURSDAY AND 2 TO 4
ADDITIONALDEGREES ON FRIDAY. FRIDAY'S MAX TEMPS WILL COME IN
WITHIN A FEW DEGREES OF NORMAL.
LESS CONFIDENCE IN THE WEEKEND FORECAST AS A VERY LARGE TROF WILL
COVER THE ENTIRE WEST COAST. A WEAK FRONT EMBEDDED IN THIS SYSTEM
WILL MOVE INTO AND THEN PASS THROUGH THE STATE SAT NIGHT AND
SUNDAY. THE MOST LIKELY SCENARIO FAVORED BY MOST OF THE ENSEMBLES
AND THE AI INFUSED EC IS FOR CLOUDY AND DRY CONDITIONS. BUT 20 TO
30 PERCENT OF THE ENSEMBLES DO BRING LIGHT RAIN TO SLO AND SBA
COUNTIES. RAINFALL AMOUNTS, IF ANY, WILL BE UNDER A QUARTER INCH
WITH INCONSEQUENTIAL RAINFALL RATES. MAX TEMPS WILL COOL 2 TO 4
DEGREES EACH DAY WITH THE INCREASED CLOUDS AND LOWERING HGTS. MAX
TEMPS BY SUNDAY WILL MOSTLY SEE HIGHS IN THE 70S ACROSS THE CSTS
AND THE VLYS. THESE MAX TEMPS WILL BE 4 TO 8 DEGREES BLO NORMAL.
LOOKING BEYOND THE 7 DAY FORECAST IT DOES APPEAR THAT A DECENT
WIND EVENT IS SHAPING UP FOR TUE AND WED. ON TUESDAY A NORTH WIND
IS POSSIBLE, BUT ON TUESDAY IT IS LOOKING MORE AND MORE LIKELY
THAT THE FIRST MODERATE SANTA ANA WIND EVENT WILL OCCUR. NOTHING
IS FOR SURE WITH A FORECAST 10 DAYS OUT, BUT IT WILL BE MONITORED.
AVIATION
20/0548Z.
AROUND 0455Z, THE MARINE LAYER DEPTH WAS AROUND 800 FEET DEEP AT
KLAX. THE TOP OF THE MARINE INVERSION WAS NEAR 1400 FEET WITH A
TEMPERATURE AROUND 22 DEGREES CELSIUS.
HIGH CONFIDENCE IN TAFS FOR KPRB, KBUR, KVNY, KPMD, AND KWJF.
MODERATE CONFIDENCE IN TAF FOR KSBA AND CMA, THERE IS A CHANCE
FOR VLIFR TO IFR CONDS FROM 12Z-18Z AT KSBA (15%) AND KCMA (20%).
LOW CONFIDENCE IN REMAINING COASTAL TAFS. FLIGHT CAT CHANGE TIMING
MAY BE OFF BY +/- 2 HOURS. FOR KSMX AND KSBP, CIGS FLIGHT CATS
MAY RAPIDLY CHANGE BETWEEN VLIFR AND VFR THROUGH EARLY MON MORNING
BEFORE CIGS REMAIN IN PLACE. THERE IS A 30% CHANCE FOR VLIFR
CONDS AT KOXR, KSMO, KLAX, AND KLGB. THERE IS A 20-40% CHANCE
FOR NO LOW CLOUDS AT KOXR, KSMO, KLAX AND KLGB, HIGHEST AT KOXR.
KLAX...LOW CONFIDENCE IN TAF. 30% CHANCE FOR VSBYS OF 1/2SM AND
OVC002 CIGS ONCE LOW CLOUDS ARRIVE TONIGHT. HOWEVER, 20% CHANCE
FOR NO LOW LOW CLOUDS. ARRIVAL OF LOW CLOD AND TRANSITION TO VFR
MAY BE OFF +/- 2 HOURS. NO SIGNIFICANT EAST WIND COMPONENT
EXPECTED.
KBUR...HIGH CONFIDENCE IN TAF.
MARINE
20/215 AM.
PATCHY DENSE FOG IS CURRENTLY OBSERVED ACROSS PORTIONS OF THE
COASTAL WATERS AND IS EXPECTED TO LAST INTO LATE THIS MORNING.
PLEASE REFER TO THE MARINE WEATHER STATEMENT FOR MORE
INFORMATION.
A MODERATE TO LONG PERIOD NORTHWEST SWELL WILL CONTINUE TO BRING
7-11 FOOT SEAS TO THE OUTER WATERS AND NEARSHORE WATERS ALONG THE
CENTRAL COAST THROUGH THE WEEK. A SMALL CRAFT ADVISORY (SCA) HAS
BEEN ISSUED FOR THIS AFTERNOON THROUGH LATE TONIGHT AS SEAS ARE
EXPECTED TO REACH 10-11 FEET FOR THE OUTER WATERS ADJACENT TO THE
CENTRAL COAST MORE THAN 20 NM AWAY FROM THE COAST. PERIOD OF SCA
LEVEL SEAS WILL CONTINUE OFF AND ON THROUGH THE WEEK. SEAS WILL
BEGIN TO INCREASE TO 11-13 FEET LATE FRIDAY THROUGH THE WEEKEND.
SEAS ARE EXPECTED REMAIN RELATIVELY SMALL INSIDE THE SOUTHERN
CALIFORNIA BIGHT, ALTHOUGH STEEP AND CHOPPY WIND WAVES WILL OCCUR
WEDNESDAY.
HIGH CONFIDENCE IN WINDS REMAINING REMAINING RELATIVELY LIGHT
THROUGH WEDNESDAY MORNING, THEN NORTHWESTERLY WINDS WILL INCREASE
TO 20-30 KNOTS ACROSS THE WATERS SOUTH OF POINT CONCEPTION,
INCLUDING THE INNER WATERS. WINDS INSIDE THE SOUTHERN CALIFORNIA
BIGHT WILL DECREASE LATE WEDNESDAY NIGHT, BUT SCA LEVEL
NORTHWESTERLY WINDS WILL CONTINUE ACROSS THE OUTER WATERS AND
EXPAND TO THE NORTH THURSDAY THROUGH FRIDAY.
LOX WATCHES/WARNINGS/ADVISORIES
CA...DENSE FOG ADVISORY IN EFFECT UNTIL 9 AM PDT THIS MORNING FOR
ZONES 340-341-346>348. (SEE LAXNPWLOX).
HIGH SURF ADVISORY IN EFFECT FROM 9 AM THIS MORNING TO 9 PM
PDT WEDNESDAY FOR ZONES 340-346. (SEE LAXCFWLOX).
PZ...SMALL CRAFT ADVISORY IN EFFECT FROM NOON TODAY TO 9 PM PDT
THIS EVENING FOR ZONES 670-673. (SEE LAXMWWLOX).
PUBLIC...RORKE
AVIATION...LEWIS
MARINE...LEWIS
SYNOPSIS...30
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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