075
FXUS66 KLOX 080318
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
818 PM PDT WED OCT 7 2026
SYNOPSIS
07/905 AM.
A MAJOR AND LONG LASTING HEAT WAVE WILL PERSIST THROUGH AT LEAST
THURSDAY WITH DANGEROUSLY HIGH TEMPERATURES, THOUGH SOME COOLING
IS EXPECTED NEAR THE COAST. TEMPERATURES WILL TREND COOLER FRIDAY
INTO SUNDAY AND THERE WILL BE AN INCREASING CHANCE OF SHOWERS AND
THUNDERSTORMS DUE TO MOISTURE FROM HURRICANE RACHEL.
SHORT TERM (WED-SAT)
07/818 PM.
***UPDATE***
ANOTHER VERY WARM DAY ACROSS THE AREA TODAY, ALBEIT A BIT COOLER
THAN YESTERDAY. ONLY ONE RECORD WAS SET TODAY, A NEW RECORD HIGH
TEMPERATURE AT BURBANK. LATEST SATELLITE AND SURFACE OBSERVATIONS
INDICATE CLEAR SKIES ACROSS THE AREA, EXCEPT FOR SOME STRATUS/FOG
ALONG THE CENTRAL COAST AND THROUGH THE SANTA BARBARA CHANNEL.
CURRENT SOUNDING DATA INDICATES MARINE INVERSION HOVERING AROUND
800 FEET IN DEPTH.
FORECAST-WISE FOR THE IMMEDIATE SHORT TERM, NO SIGNIFICANT ISSUES
ARE EXPECTED. OVERNIGHT, STRATUS/FOG LOOKS TO BE A BIT MORE
WIDESPREAD ACROSS THE CENTRAL COAST AND ACROSS THE COASTAL PLAIN
SOUTH OF POINT CONCEPTION. DO NOT ANTICIPATE ANY NOTICEABLE
INCREASE IN INVERSION DEPTH OVERNIGHT, SO PATCHY DENSE FOG WILL BE
AN ISSUE ANYWHERE STRATUS/FOG DEVELOPS. OTHER THAN THE MARINE
LAYER ISSUES, SKIES WILL REMAIN CLEAR OVERNIGHT. OVERNIGHT LOWS
WILL REMAIN RATHER WARM, GENERALLY IN THE MID 60S TO MID 70S. SO,
HEAT ISSUES WILL CONTINUE THROUGH THE OVERNIGHT HOURS.
OVERALL, CURRENT FORECAST HAS GOOD HANDLE ON THE IMMEDIATE SHORT
TERM. SO, NO SIGNIFICANT UPDATES ARE EXPECTED. TOMORROW LOOKS TO
BE THE LAST DAY OF SIGNIFICANT HEAT, THEN THE AREA IS STILL ON
TRACK FOR A NOTICEABLE COOLING TREND THIS WEEKEND WITH SOME RAIN
EARLY NEXT WEEK.
***FROM PREVIOUS DISCUSSION***
SYNOPTICALLY, A 590 DAM HIGH EXTENDS FROM THE BAY AREA THROUGH
MEXICO TO OUR SOUTHEAST. BY SATURDAY, THAT HIGH HAS MOVED EAST TO
TEXAS AND A LARGE TROUGH WILL DROP DOWN THE CALIFORNIA COAST,
ALLOWING THE TRACK OF THE TROPICAL SYSTEM TO OUR SOUTHWEST
(RACHEL) TO TURN TOWARDS THE BAJA PENINSULA. WHILE THE TROPICAL
WILL REMAIN WELL SOUTH OF THE CWA, PERIPHERAL MOISTURE AND SWELLS
COULD BRING A RAINY WEEKEND WITH COASTAL IMPACTS.
THE HIGH PRESSURE OVERHEAD WILL SLOWLY WEAKEN TODAY AND THURSDAY.
BY FRIDAY IT WILL BE NOTHING MORE THAN A WEAK RIDGE. AT THE
SURFACE, ONSHORE FLOW WILL INCREASE EACH DAY EXCEPT ACROSS THE
CENTRAL COAST. THIS COMBINATION OF LOWERING HEIGHTS AND
INCREASING ONSHORE FLOW WILL KICK OFF A THREE-DAY COOLING TREND,
ESPECIALLY ON FRIDAY.
THE COOLING TODAY WILL NOT BE ENOUGH TO ELIMINATE THE HEAT RISK
WITH MOSTLY 90S ACROSS THE COASTS, AND 98 TO 105 IN THE VALLEYS.
IT ONLY HAS REACHED 96 SO FAR TODAY IN DOWNTOWN LA, SO THE
CONSECUTIVE TRIPLE DIGIT DAY STREAK WILL LIKELY END AT 5.
MOST AREAS WILL COOL 2 TO 4 DEGREES ON THURSDAY. MORE NOTICEABLE
COOLING ARRIVES ON FRIDAY; 4 TO 8 DEGREES ACROSS THE BOARD. THIS
WILL BE ENOUGH TO FINALLY ELIMINATE THE HEAT RISK.
SOME LOW CLOUDS WILL LIKELY DEVELOP SOUTH OF PT CONCEPTION AND
THERE WILL BE MORE LOW CLOUDS ACROSS THE CENTRAL COAST AS WELL.
THIS INCREASING TREND WILL CONTINUE FRIDAY MORNING WHERE MOST
COASTAL AREAS WILL WAKE UP TO LOW CLOUDS AND PATCHY FOG.
THE FORECAST FOR SATURDAY WILL DEPEND ON THE EXACT TRACK OF
RACHEL, BUT IT IS LIKELY TO BRING INCREASING CLOUDINESS AND
CONTINUED COOLING. LIGHT RAIN COULD ARRIVE AS EARLY AS SATURDAY
MORNING IN LA AND VENTURA COUNTIES, BUT MORE REALISTICALLY IT WILL
NOT ARRIVE UNTIL SATURDAY NIGHT INTO SUNDAY MORNING.
LONG TERM (SUN-WED)
07/231 PM.
AN EARLY SEASON COLD UPPER LOW MOVES OUT OF BRITISH COLUMBIA AND
INTO THE WEST COAST, DEVELOPING INTO A LARGE TROF AND BY SUNDAY.
ONSHORE FLOW WILL INCREASE AND THERE WILL BE A MUCH MORE ROBUST
MARINE LAYER STRATUS LAYER ACROSS THE COASTS AND SOME VALLEYS.
MAX TEMPS WILL DROP AN ADDITIONAL 4 TO 8 DEGREES ON SUNDAY.
SUNDAY'S MAX TEMPS ACROSS THE COASTS AND VALLEYS SOUTH OF PT
CONCEPTION WILL ONLY BE IN THE 70S AND THE CENTRAL COAST WILL SEE
NOTHING BUT 60S.
THE MOST LIKELY PERIOD OF RAIN FROM RACHEL'S MOISTURE IS 9AM
SUNDAY THROUGH 9AM MONDAY IN LA AND VENTURA COUNTY. SOME LIGHT
RAIN COULD EXTEND INTO SANTA BARBARA AND SLO COUNTIES AS WELL.
AN UPPER LOW WILL MOVE OVER THE CENTRAL COAST DURING THE DAY ON
MONDAY. HGTS COULD FALL AS LOW AS 562 DAM. THIS LOW AND THE
REMNANT MOISTURE WILL BRING A CHANCE OF RAIN SHOWERS AND A 5-10%
CHANCE OF TSTMS TO THE ENTIRE AREA DURING THE DAY.
WHILE SLO AND SBA COUNTIES WILL LIKELY SEE LESS THAN A TENTH OF
AN INCH OF RAIN, VENTURA AND LA COUNTIES AMOUNTS WILL BE MORE LIKE
0.5" THE MOST RAIN IS EXPECTED IN THE EASTERN PORTION OF THE LA
COUNTY MOUNTAINS, WHICH COULD GET UP TO 2 INCHES OF RAIN. THE
UPPER LOW, THE CLOUDS AND THE RAIN WILL BRING ANOTHER 3 OR 4
DEGREES OF COOLING TO MOST AREAS AND HIGHS WILL ONLY RANGE FROM
THE UPPER 60S TO LOWER 70S. LITTLE CHANGE ACROSS THE CENTRAL
COAST.
RAIN SHOULD END BY TUESDAY AND DECREASING CLOUDS AND WARMING ARE
EXPECTED BOTH TUESDAY AND WEDNESDAY, AND DOWNTOWN LA SHOULD BE IN
THE MID-70S BY THEN.
AVIATION
07/2305Z.
AT 2230Z AT KLAX, THE MARINE LAYER WAS 600 FEET DEEP. THE TOP OF
THE INVERSION WAS 2100 FEET WITH A TEMPERATURE OF 30 DEGREES
CELSIUS.
FOR 00Z TAF PACKAGE, HIGH CONFIDENCE IN CAVU CONDITIONS FOR KPRB,
KBUR, KVNY, KWJF AND KPMD.
FOR KSMX AND KSBA, MODERATE CONFIDENCE IN 00Z TAFS WITH TIMING OF
FLIGHT CATEGORY CHANGES +/- 2 HOURS OF CURRENT FORECASTS.
FOR KSBA, KOXR, KCMA, KSMO, KLAX AND KLGB, LOW CONFIDENCE IN 00Z
TAFS AS THERE IS A 50% CHANCE THAT CIG/VSBY RESTRICTIONS DO NOT
DEVELOP.
KLAX...LOW TO MODERATE CONFIDENCE IN 00Z TAF. THERE IS A 50%
CHANCE THAT CIG/VSBY RESTRICTIONS DO NOT DEVELOP. IF CIG/VSBY
RESTRICTIONS DO DEVELOP, TIMING OF FLIGHT CATEGORY CHANGES COULD
BE +/- 3 HOURS OF CURRENT FORECASTS WITH AN EQUAL CHANCE OF IFR OR
LIFR CONDITIONS. NO SIGNIFICANT EASTERLY WIND COMPONENT IS
EXPECTED.
KBUR...HIGH CONFIDENCE IN 00Z TAF AS CAVU CONDITIONS ARE EXPECTED
THROUGH THE PERIOD.
MARINE
07/800 PM.
RELATIVELY QUIET CONDITIONS EXPECTED ACROSS THE COASTAL WATERS
THROUGH FRIDAY. LOCALIZED SMALL CRAFT ADVISORY (SCA) GUSTS MAY
OCCUR EACH AFTERNOON AND EVENING BETWEEN POINT CONCEPTION AND SAN
NICOLAS ISLAND. ADDITIONALLY, A SHORT LIVED SCA IS IN EFFECT FOR
THE NORTHERN PORTION OF THE OUTER WATERS (NORTH OF POINT SAL) THROUGH
LATE EVENING FOR NORTHWEST WINDS. NIGHT THROUGH MORNING DENSE FOG
MAY AFFECT PORTIONS OF THE COASTAL WATERS ADJACENT TO THE CENTRAL
COAST AND SOUTH TO SAN NICOLAS ISLAND.
THE BIGGEST CONCERN THIS WEEKEND WILL BE POTENTIAL IMPACTS FROM
THE INTERACTION BETWEEN A TROUGH COMING DOWN FROM THE NORTH AND
REMNANTS OF HURRICANE RACHEL FOCUSED ACROSS THE WATERS ADJACENT TO
LOS ANGELES AND ORANGE COUNTIES. THERE IS STILL A CONSIDERABLE
AMOUNT OF UNCERTAINTY IN REGARDING TO RACHEL'S FINAL TRACK WHICH
WILL DETERMINE THE EXACT DETAILS. THE MOST RECENT GUIDANCE HAS
SHIFTED THE TRACK WELL TO THE SOUTH OF THE COASTAL WATERS, WHICH
WOULD LIMIT IMPACTS. HOWEVER, STRONG SCA W-SW WINDS ARE STILL A
POSSIBILITY AS THE SYSTEM INTERACTS WITH THE TROUGH WITH A 20%
CHANCE OF GALES ESPECIALLY ACROSS THE INNER WATERS. PERIODS OF LIGHT
TO MODERATE RAIN, WITH A 10% CHANCE OF THUNDERSTORMS WILL BE
POSSIBLE ACROSS THE WATERS AS EARLY AS SATURDAY LASTING INTO AS
LATE AS TUESDAY EVENING (HIGHEST CONFIDENCE IN SUNDAY/MONDAY
TIMEFRAME). IN ADDITION, INCREASING WEST TO NORTHWEST WINDS AND
SEAS (10+ FOOT) ARE EXPECTED ACROSS THE OUTER WATERS THIS WEEKEND
INTO MONDAY.
PLEASE CONTINUE TO MONITOR THE FORECAST.
BEACHES
07/225 PM.
THE COASTAL FLOOD ADVISORIES HAVE BEEN EXTENDED INTO TUESDAY
AFTERNOON. SOUTHERLY SWELLS INCLUDING FROM HURRICANE RACHEL
WILL CONTINUE TO IMPACT THE LA/VTA COASTLINE. 180-190 AT
12 SECONDS WILL POSE THE MOST RISK FROM MALIBU TO VENTURA
THURSDAY AND FRIDAY. LONG BEACH AREA IS ALSO AT A RELATIVELY
HIGHER RISK DUE TO VULNERABILITIES FROM PREVIOUS COASTAL EVENTS.
HIGH TIDES WILL REMAIN SIMILAR IN HEIGHT AT 6.5-7.0 FT THROUGH
THURSDAY AND WITH A 0.3 FT REDUCTION IN THE EVENING TIDES ON
FRIDAY.
HURRICANE RACHEL IS EXPECTED TO TURN NORTHEAST AND WILL PICK UP
IN MOVEMENT SPEED LIKELY MAKING LANDFALL SUNDAY SOMEWHERE IN
NORTHERN BAJA CALIFORNIA OR IN THE VICINITY OF THE MEXICO UNITED
STATES BORDER (AS A POST-TROPICAL SYSTEM). THE EXACT TRACK WILL
BECOME MORE CLEAR LIKELY IN A DAY OR TWO AS THE SYSTEM TURNS TO
THE NORTHEAST. DEVIATIONS IN THE FINAL TRACK COULD INFLUENCE THE
MAGNITUDE OF IMPACTS FOR THE AREA. THE MOST REASONABLE SOLUTION AT
THIS TIME WILL LIKELY HAVE CONSIDERABLE TO SIGNIFICANT IMPACTS
ESPECIALLY FOR VULNERABLE BEACHES SUCH AS LONG BEACH. THE TIME
WINDOW FOR MOST CONCERN IS SUNDAY ESPECIALLY DURING THE MORNING
HIGH TIDE.
THE TIDE IS EXPECTED TO BE 7.5 FT (+/- 0.5 FT). IF RACHEL TAKES A
MORE NORTHERLY TRACK, THE COMBINATION OF THE INCREASED WIND WAVE
AND LOWER SFC PRESSURE WOULD RESULT IN HIGHER TIDES- VICE VERSA.
FOR THE CENTRAL COAST, HIGH SURF ADVISORIES WILL BE NEEDED SATURDAY
THROUGH MONDAY. IN ADDITION, THERE IS A MODERATE RISK FOR SOME
BEACH EROSION AND ISOLATED, MINOR COASTAL FLOODING.
COASTAL FLOODING CONCERNS WILL CONTINUE INTO EARLY NEXT WEEK
REFER TO CFWLOX FOR MORE DETAILS AND PLEASE CONTINUE TO MONITOR
THE FORECAST FOR THE LATEST INFORMATION.
LOX WATCHES/WARNINGS/ADVISORIES
CA...EXTREME HEAT WARNING IN EFFECT UNTIL 8 PM PDT THURSDAY FOR
ZONES 38-87-88-349>358-362-366>375-548-550. (SEE LAXNPWLOX).
COASTAL FLOOD ADVISORY IN EFFECT UNTIL 2 PM PDT TUESDAY FOR
ZONES 87-354-362-366. (SEE LAXCFWLOX).
HEAT ADVISORY IN EFFECT UNTIL 8 PM PDT THURSDAY FOR ZONES
340>348. (SEE LAXNPWLOX).
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PDT THURSDAY FOR
ZONE 670. (SEE LAXMWWLOX).
PUBLIC...RORKE/JLD/THOMPSON
AVIATION...RAT
MARINE...BLACK/KL
BEACHES...BLACK
SYNOPSIS...MW
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