711
FXUS66 KLOX 040517
AFDLOX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1017 PM PDT WED SEP 3 2025
UPDATED AVIATION DISCUSSION
SYNOPSIS
03/130 PM.
HEAT RELIEF IS COMING. TEMPERATURES WILL SLOWLY LOWER THROUGH
FRIDAY, INCLUDING THE ABNORMALLY WARM OVERNIGHT TEMPERATURES.
MONSOONAL MOISTURE WILL REMAIN OVER THE REGION THROUGH THURSDAY,
BUT THE RISKS FOR SIGNIFICANT IMPACTS HAVE LOWERED. SLIGHT WARMING
ON TRACK SATURDAY THROUGH MONDAY, THEN A LIKELY BIG COOL DOWN TO
FOLLOW.
SHORT TERM (WED-SAT)
03/846 PM.
***UPDATE***
ALTHOUGH CLOUDS DEVELOPED OVER THE MOUNTAINS TODAY, NO SHOWERS
DEVELOPED THIS AFTERNOON AND EVENING, IN LINE WITH THE DIRECTION
GUIDANCE WAS TRENDING. TEMPERATURES WERE NEARLY THE SAME AS
TUESDAY'S HIGHS, WITH 90S COMMON FROM THE WARMER VALLEYS TO THE
INTERIOR, AND 70S TO 80S NEAR THE COASTS. WEAKENING HIGH PRESSURE
SHOULD RESULT IN SLIGHTLY COOLER TEMPERATURES THURSDAY, WITH A
MORE SIGNIFICANT COOL DOWN FRIDAY AS AN UPPER LEVEL LOW
APPROACHES FROM THE NORTHWEST. TONIGHT, MARINE LAYER CLOUDS HAVE
FORMED OFF THE CENTRAL COAST, AND EXPECTING TO SEE A DEEPENING
MARINE LAYER WITH POTENTIAL FOR CLOUDS TO INCREASE IN COVERAGE
OVER THE NEXT FEW DAYS. THE CURRENT FORECAST LOOKS ON TRACK,
HOWEVER LOW CONFIDENCE IN SHOWERS FOR THE MOUNTAINS ON THURSDAY.
***FROM PREVIOUS DISCUSSION***
STILL KEEPING THE 10 TO 20 PERCENT CHANCE OF THUNDERSTORMS FOR
EACH AFTERNOON THROUGH TOMORROW OVER THE LOS ANGELES AND VENTURA
COUNTY MOUNTAINS AS THE CONVECTIVE PARAMETERS ARE STILL THERE, BUT
THE CHANCE FOR EVERYTHING TO LINE UP FOR FLASH FLOODING IS
EXTREMELY LOW. THE LATEST CONSENSUS OF TRACKS FOR THE REMNANTS OF
TROPICAL STORM LORENA CONTINUES TO PUSH IT FURTHER TO THE EAST OF
OUR AREA. THIS IS STILL SOMETHING TO MONITOR, BUT STILL LOOKS LIKE
TO BE ANY PART OF OUR STORY. AS A RESULT, PRECIPITABLE WATER
VALUES SHOULD FALL BELOW ONE INCH BY FRIDAY, AND THE THUNDERSTORM
THREAT IS BELOW MENTIONABLE BY THEN. NOT SEEING ANY APPRECIABLE
MONSOONAL SURGE CHANCES THROUGH AT LEAST THE MIDDLE OF NEXT WEEK.
THE HIGH PRESSURE CENTER THAT BROUGHT ALL THE HEAT STRETCHING BACK
TO LAST WEEK WILL CONTINUE TO WEAKEN THROUGH FRIDAY OR SATURDAY.
ONSHORE FLOW AND PRESSURE GRADIENTS WILL ALSO TREND MORE AND MORE
ONSHORE EACH DAY THROUGH SATURDAY. THIS WILL ALL LEAD TO A STEADY
LOWERING OF DAYTIME TEMPERATURES. MORE SIGNIFICANTLY, WITH THE
MONSOONAL MOISTURE STEADILY DECLINING EACH DAY, NIGHT TIME
TEMPERATURES AND OVERALL MUGGINESS WILL NOTICEABLY IMPROVE EACH
DAY. AS SUCH, THE CURRENT HEAT ADVISORIES WILL BE ALLOWED TO
EXPIRE ON TIME AT 6PM THIS EVENING WITH NO CHANGES OR EXTENSIONS
PLANNED.
OTHER THAN THAT, WE ARE LOOKING AT A PRETTY BENIGN REST OF THE
WEEK. THE FLOW ALOFT WILL TURN FROM MOIST SOUTHEAST TODAY TO DRY
SOUTHWEST BY SATURDAY. SOME GUSTY SUNDOWNER WINDS WILL FORM EACH
EVENING, AS WELL AS SOME GUSTY ONSHORE WINDS OVER THE INTERIOR,
BUT NOTHING LOOKS TO APPROACH ADVISORY LEVELS.
LONG TERM (SUN-WED)
03/220 PM.
HIGH PRESSURE ALOFT WILL PEAK ON SUNDAY OR MONDAY (AROUND 590
DECAMETERS) WITH ONSHORE PRESSURE GRADIENTS WEAKENING TO AROUND +1
MILLIBARS. THIS SHOULD ALLOW TEMPERATURES TO PUSH BACK UP TO A FEW
DEGREES ABOVE NORMAL. THANKFULLY OVERNIGHT TEMPERATURES WILL
CHANGE LITTLE DUE TO THE DRY AIRMASS (NOTHING LIKE THE VERY WARM
NIGHTS WE HAVE BEEN HAVING). THE RISK FOR HEAT ADVISORIES IS
CLOSE TO ZERO.
MORE AND MORE OF THE ENSEMBLE PROJECTIONS (ON THE ORDER OF 70%)
ARE NOW ON BOARD FOR A LARGE TROUGH OF LOW PRESSURE QUICKLY
DROPPING OVER THE WEST COAST ON TUESDAY THEN MOVING VERY SLOWLY
FOR THE REST OF NEXT WEEK. THIS SURELY MEANS AN EXTENDED PERIOD OF
TEMPERATURES MUCH BELOW NORMAL FROM TUESDAY ONWARD AND A LIKELY
DEEP AND EXPANSIVE MARINE LAYER. SOME SOLUTIONS HAVE THE CORE OF
THE LOW CUTTING OFF AND DRIFTING RIGHT OVER SOUTHERN CALIFORNIA ON
FRIDAY. SUCH A SOLUTION COULD BRING A FEW SHOWERS BUT WE HAVE SOME
TIME TO FIGURE THAT OUT.
AVIATION
04/0516Z.
DUE TO A NATIONAL METAR OUTAGE, THERE WILL BE LIMITED OR NO
AMENDMENTS UNTIL OBSERVATIONS ARE RESTORED.
AT 0424Z AT KLAX, THE MARINE LAYER WAS 700 FT DEEP. THE TOP OF
THE INVERSION WAS AT 1400 FT WITH A TEMPERATURE OF 28 C.
HIGH CONFIDENCE IN VFR TAFS FOR KPRB, KBUR, KVNY, KPMD, AND KWJF.
LOW CONFIDENCE IN ARRIVAL OF LOW CLOUDS FOR KOXR AND KCMA. THERE
IS A 40% CHANCE FOR LOW CLOUDS TONIGHT. IF LOW CLOUDS ARRIVE, 40%
CHANCE FOR LIFR CONDS.
MODERATE CONFIDENCE IN REMAINING TAFS. DISSIPATION MAY BE OFF +/-
90 MINUTES FOR KSBP AND KSMX. THERE IS A 20% CHANCE FOR VSBYS
LESS THAN 1SM AT KSMX AND KSBP. THERE IS A 15% CHANCE FOR IFR
CONDS AT KSMO, KLAX, AND KLGB BETWEEN 10Z AND 17Z.
KLAX...MODERATE CONFIDENCE IN TAF. THERE IS A 15% CHANCE FOR IFR
CONDITIONS 10Z TO 17Z THURSDAY. NO SIGNIFICANT EAST WIND COMPONENT
EXPECTED.
KBUR...HIGH CONFIDENCE IN VFR TAF.
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 TO 9 PM PDT THURSDAY
FOR ZONE 645. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT FROM NOON THURSDAY TO 3 AM PDT
SATURDAY FOR ZONE 670. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PDT THURSDAY FOR
ZONES 673-676. (SEE LAXMWWLOX).
PUBLIC...PHILLIPS/KITTELL
AVIATION...LEWIS
MARINE...BLACK/LEWIS
SYNOPSIS...RK
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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