909
FXUS66 KLOX 170046
AFDLOX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
546 PM PDT TUE SEP 16 2025
UPDATED AVIATION SECTION
SYNOPSIS
16/146 PM.
IT WILL BE WARM AND MUGGY THROUGH FRIDAY AS REMNANTS OF TROPICAL
STORM MARIO MOVE INTO THE AREA. TEMPERATURES WILL COOL THROUGH THE
PERIOD BUT HUMIDITIES WILL BE MUCH HIGHER THAN NORMAL. RAIN AND
THUNDERSTORM CHANCES WILL BEGIN WEDNESDAY NIGHT AND CONTINUE INTO
AT LEAST EARLY FRIDAY. OVER THE WEEKEND INTO EARLY NEXT WEEK THERE
IS SLIGHT CHANCE OF SHOWERS AS ADDITIONAL MOISTURE FROM THE SOUTH
ARRIVES. TEMPERATURES WILL BE NEAR NORMAL AND THE MUGGY WEATHER
WILL CONTINUE INTO EARLY NEXT WEEK.
SHORT TERM (TDY-FRI)
16/215 PM.
MOISTURE FROM WHAT WAS TROPICAL STORM MARIO IS RAPIDLY MOVING UP
THE BAJA COAST AND WILL BE ENTERING US WATERS OVERNIGHT TONIGHT.
IT'S BEEN AN ACTIVE DAY OF THUNDERSTORMS ACROSS THE SPINE OF
NORTHERN BAJA BUT SO FAR NO CONVECTION ON THIS SIDE OF THE BORDER.
WHILE THERE STILL REMAINS A LOT OF UNCERTAINTIES, CONFIDENCE IS
GROWING THAT MOST AREAS ACROSS THE 4 COUNTY AREA WILL GET AT LEAST
SOME RAIN BETWEEN WEDNESDAY AFTERNOON AND THURSDAY. AMOUNTS ARE
GOING TO BE HIGHLY VARIABLE, WITH SOME AREAS POSSIBLY JUST GETTING
AROUND A TENTH OF AN INCH, AND OTHER AREAS (POSSIBLY NOT THAT FAR
AWAY) AS MUCH AS 1-2 INCHES. AS OF NOW THE HIGHER RAIN AMOUNTS ARE
EXPECTED IN THE MOUNTAINS SOUTH OF PT CONCEPTION, BUT IF MARIO'S
TRACK REVERTS BACK TO ITS FARTHER WEST SOLUTION THEN HEAVIER
AMOUNTS COULD REACH THE CENTRAL COAST. THERE ARE ALSO SOME SIGNALS
IN THE MODELS INDICATING THE POTENTIAL FOR SEVERE WEATHER,
INCLUDING AN ISOLATED SMALL TORNADO. THE BEST CHANCE FOR ANY
LIGHTNING WOULD LIKELY BE AS THE MOISTURE IS JUST ARRIVING
WEDNESDAY NIGHT INTO EARLY THURSDAY, AFTER WHICH THE ENVIRONMENT
MAY BE TOO MOIST WITH WITH TOO MUCH CLOUD COVER TO SUPPORT
THUNDER DEVELOPMENT. RAIN RATES UP TO AT LEAST A HALF INCH ARE
POSSIBLE WITH THE HEAVIER CELLS, AND CAN'T RULE OUT RATES AS HIGH
AS AN INCH PER HOUR GIVEN THE 2+" OF PRECIPITABLE WATER.
NEEDLESS TO SAY IT WILL BECOME INCREASINGLY MUGGY LATER WEDNESDAY
INTO THURSDAY. TEMPERATURES ARE EXPECTED TO COOL A FEW DEGREES IN
MOST AREAS WEDNESDAY AND SEVERAL MORE DEGREES THURSDAY WITH
INCREASING CLOUD COVER AND SHOWERS. OVERNIGHT LOWS WILL BE MUCH
WARMER THAN NORMAL AS WELL AS THE MOISTURE ALOFT WILL TRAP A LOT
OF THE HEAT FROM THE DAYTIME.
PRECIP CHANCES WILL DECREASE LATER THURSDAY NIGHT INTO FRIDAY
MORNING AND SHOULD BE COMPLETELY GONE BY FRIDAY AFTERNOON.
TEMPERATURES WILL STILL BE 5-10 DEGREES BELOW NORMAL, BUT WITH
STILL MUCH HIGHER THAN NORMAL HUMIDITY IT WILL FEEL MUCH WARMER.
LONG TERM (SAT-TUE)
16/231 PM.
THE WEEKEND FORECAST HAS BECOME LESS CERTAIN AS THERE ARE SOME
MODELS NOW BRINGING UP SOME ADDITIONAL MOISTURE AND INSTABILITY
THAT COULD TRIGGER ISOLATED SHOWERS. THIS MAY END UP JUST BEING
OVER THE MOUNTAINS BUT IF THERE'S ANY LEFT OVER INSTABILITY AFTER
MARIO DEPARTS IT MAY NOT TAKE MUCH TO TRIGGER AN BRIEF SHOWER. THE
MOST LIKELY OUTCOME IS A DRY WEEKEND WITH TEMPERATURES WARMING
BACK TO NORMAL LEVELS AND STILL WITH ELEVATED HUMIDITY LEVELS.
NEXT WEEK IS ALSO UNCERTAIN AS ANOTHER TROPICAL WAVE OVER MEXICO
MOVES OUT OVER THE PACIFIC. THE UPPER LEVEL PATTERN MAY BE
FAVORABLE TO GET SOME OF THAT MOISTURE INTO THE AREA EARLY NEXT
WEEK BUT WILL HAVE TO SEE HOW THE PATTERN EVOLVES THE NEXT FEW
DAYS. THERE ALSO SOME MODEL SOLUTIONS INDICATING A STRONG HIGH
PRESSURE SYSTEM DEVELOPING OVER SOUTHERN CALIFORNIA WITH THE
POTENTIAL FOR TRIPLE DIGIT HEAT TO RETURN TO THE VALLEYS.
AVIATION
17/0045Z.
AT 0015Z AT KLAX, THE MARINE INVERSION WAS AROUND 600 FEET DEEP.
THE TOP OF THE INVERSION WAS 2800 FEET WITH A TEMPERATURE OF 27
DEGREES CELSIUS.
HIGH CONFIDENCE IN VALLEY AND DESERT TAFS AS VFR CONDITIONS ARE
EXPECTED THROUGH THE PERIOD. 20% CHANCE OF -SHRA POSSIBLE AT KPMD
AND KWJF THROUGH 06Z, AND AFTER 20Z.
FOR COASTAL TAFS, LOW TO MODERATE CONFIDENCE IN TAFS. LOW
CONFIDENCE IN TAFS FOR KSBP. THERE IS A 40% CHANCE LOW CLOUDS TO
NOT MAKE IT TO KSBP TONIGHT. FOR KSMX AND KSBP, 50% CHANCE FOR
VLIFR CONDS AT ANY POINT WHILE CIGS ARE PRESENT. FOR SITES SOUTH
OF POINT CONCEPTION, THERE IS A 20-30% CHANCE FOR LIFR TO IFR
CONDS. THERE IS A 20% CHANCE FOR -SHRA AND -TSRA AFTER 20Z.
CHANCES INCREASE AFTER 00Z THU.
KLAX...MODERATE CONFIDENCE IN TAF. HIGH CONFIDENCE IN VFR
CONDITIONS THROUGH THIS EVENING. FOR TONIGHT, THERE IS A 30%
CHANCE OF CIGS BETWEEN 004-010 FROM 08Z-17Z. 20% CHANCE OF -SHRA
AFTER 20Z, THEN A 30% CHANCE 00Z-06Z. NO SIGNIFICANT EAST WIND
COMPONENT IS EXPECTED.
KBUR...HIGH CONFIDENCE IN TAF. 20% CHANCE FOR -SHRA AFTER 20Z.
MARINE
16/144 PM.
FOR THE OUTER WATERS, MODERATE TO HIGH CONFIDENCE IN CURRENT
FORECAST. TONIGHT THROUGH SATURDAY, HIGH CONFIDENCE IN WINDS AND
SEAS REMAINING BELOW SMALL CRAFT ADVISORY (SCA) LEVELS. ON SUNDAY,
THERE IS A 30-50% CHANCE OF SCA LEVEL WINDS, ESPECIALLY ACROSS
PZZ673/676.
FOR THE INNER WATERS NORTH OF POINT SAL, MODERATE TO HIGH
CONFIDENCE IN CURRENT FORECAST. TONIGHT THROUGH SATURDAY, HIGH
CONFIDENCE IN WINDS AND SEAS REMAINING BELOW SCA LEVELS. ON
SUNDAY, THERE IS A 20-30% CHANCE OF SCA LEVEL WINDS IN THE
AFTERNOON AND EVENING HOURS.
FOR THE INNER WATERS SOUTH OF POINT CONCEPTION, MODERATE TO HIGH
CONFIDENCE IN CURRENT FORECAST. TONIGHT THROUGH SATURDAY, HIGH
CONFIDENCE IN WINDS AND SEAS REMAINING BELOW SCA LEVELS. ON
SUNDAY, THERE IS A 20-30% CHANCE OF SCA LEVEL WINDS ACROSS WESTERN
SECTIONS.
FOR WEDNESDAY THROUGH FRIDAY, THE REMNANTS OF TROPICAL STORM
MARIO WILL IMPACT THE SOUTHERN CALIFORNIA COASTAL WATERS. A
PERIOD OF SHOWERS, MOST LIKELY LATE WEDNESDAY AND THURSDAY, WILL
MOVE OVER THE WATERS. ADDITIONALLY, THERE WILL BE A CHANCE OF
THUNDERSTORMS. ANY THUNDERSTORMS THAT DEVELOP WILL BE CAPABLE OF
FREQUENT LIGHTNING AS WELL AS STRONG AND ERRATIC WINDS. PLEASE
MONITOR THE FORECAST IF YOU HAVE ANY PLANS ON GOING OUT ON THE
WATER THIS WEEK.
LOX WATCHES/WARNINGS/ADVISORIES
CA...HEAT ADVISORY IN EFFECT UNTIL 7 PM PDT THIS EVENING FOR ZONES
88-357-358-362-369>374. (SEE LAXNPWLOX).
PZ...NONE.
PUBLIC...MW
AVIATION...LEWIS
MARINE...RAT
SYNOPSIS...MW
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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