802
FXUS66 KLOX 091019
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
319 AM PDT SUN AUG 9 2026
SYNOPSIS
09/205 AM.
NIGHT THROUGH MORNING LOW CLOUDS AND PATCHY DENSE FOG WILL AFFECT
SOME COASTAL AREAS AND COASTAL VALLEYS THROUGH THE WEEKEND. AWAY
FROM THE COAST, HAZARDOUS HEAT WILL CONTINUE INTO THIS EVENING,
WITH NEAR TO ABOVE NORMAL TEMPERATURES AROUND THE BEACHES.
STARTING MONDAY, A GRADUAL COOLING TREND WILL LAST THROUGH THE
WEEK, WITH NEAR TO BELOW NORMAL TEMPERATURES BY LATE WEEK. OTHER
THAN A SMALL CHANCE OF MOUNTAIN SHOWERS DURING THE AFTERNOON AND
EVENING HOURS THROUGH EARLY NEXT WEEK, DRY CONDITIONS WILL
PREVAIL.
SHORT TERM (TDY-TUE)
09/319 AM.
A STRONG RIDGE OF HIGH PRESSURE ALOFT REMAINS CENTERED NEAR THE
FOUR CORNERS AREA, WITH HIGH PRESSURE EXTENDING WESTWARD ACROSS
SOUTHERN CALIFORNIA. DESPITE THE HIGH PRESSURE SYSTEM REMAINING IN
PLACE, IT WILL START TO WEAKEN, AND 500 MB HEIGHTS OVER THE REGION WILL
START TO FALL FROM HERE ON OUT THROUGH THE FORECAST PERIOD. WHILE 500
MB HEIGHTS WILL FALL TO AROUND 593-594 DAM TODAY, COMPARED TO THE
PEAK OF 596 DAM YESTERDAY, AND A LITTLE BIT OF COOLING WILL BE
POSSIBLE. HOWEVER, MODERATE TO HIGH HEAT RISK WILL STILL IMPACT
THE AREA. HIGH TEMPERATURES TODAY FOR AREAS AWAY FROM THE COAST
WILL BE IN THE LOW 90S TO OVER 100 DEGREES, AND IN THE WARMEST
LOCATIONS, READINGS WERE UP TO 108 DEGREES WILL BE POSSIBLE
(WARMEST OVER THE ANTELOPE VALLEY, NORTHERN VENTURA COUNTY
MOUNTAINS, AND CUYAMA VALLEY, WHERE EXTREME HEAT WARNINGS REMAIN
IN PLACE THROUGH THIS EVENING). ALONG THE IMMEDIATE COAST, THE
MARINE LAYER WILL KEEP THE HIGH TEMPERATURES A LITTLE COOLER, IN
THE 70S AND 80S, ALTHOUGH MORE HUMID CONDITIONS PERSIST THERE DUE
TO WARM OCEAN TEMPERATURES. HIGHS IN MOST AREAS HAVE BEEN RUNNING
ABOUT 5 TO 10 DEGREES ABOVE NORMAL. HEAT ADVISORIES AND EXTREME
HEAT WARNINGS REMAIN IN EFFECT THROUGH THIS EVENING FOR ALL AREAS
AWAY FROM THE IMMEDIATE COAST AS WELL AS THE INTERIOR COAST OF SAN
LUIS COUNTY.
MORE SIGNIFICANT COOLING IS ANTICIPATED FOR EARLY THIS WEEK AS
THE UPPER HIGH WEAKENS AND HEIGHTS DIMINISH OVER THE REGION,
COMBINED WITH INCREASING ONSHORE FLOW. THERE WILL BE A FEW DEGREES
OF COOLING INTO MONDAY, AND MORE SIGNIFICANT COOLING TUESDAY WITH
ALL LOCATIONS LIKELY TO DROP INTO THE 90S OR LOWER.
MEANWHILE, SOUTHEAST FLOW ALOFT WILL RESULT IN CLOCKWISE FLOW
AROUND THE FOUR-CORNERS RIDGE ALOFT, EFFECTIVELY DRAWING
MONSOONAL MOISTURE INTO SOUTHWEST CALIFORNIA. WHILE THE MOISTURE
IS SOMEWHAT MARGINAL, A WEAK SHORTWAVE DISTURBANCE MOVING AROUND
THE RIDGE WILL BRING A SLIGHTLY INCREASED CHANCE OF CONVECTION TO
THE AREA THIS AFTERNOON INTO MONDAY. IT MAY RESULT IN SOME
INCREASED MID TO UPPER LEVEL CLOUDINESS, ALONG WITH A 5-15 PERCENT
CHANCE OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS,
HIGHEST OVER THE LA/VENTURA COUNTY MOUNTAINS AND ANTELOPE VALLEY.
THERE IS ALSO A LOWER (5%) CHANCE OF AN ISOLATED SHOWER OR
THUNDERSTORM OVER THE COAST AND VALLEY AREAS, EXTENDING OUT OVER
THE COASTAL WATERS.
IF THUNDERSTORMS DO OCCUR, THERE IS A CHANCE OF ISOLATED DRY
LIGHTNING WITH A RISK OF FIRE STARTS, ADDING TO THE ONGOING FIRE
WEATHER CONCERNS. THE INCREASE IN MONSOONAL MOISTURE ALONG WITH
THE WARMER THAN NORMAL SEA TEMPERATURES WILL ALSO INCREASE
HUMIDITIES, ESPECIALLY FOR THE COAST AND COASTAL VALLEY AREAS.
THIS WILL RESULT IN WARMER OVERNIGHT LOWS AND MORE HUMID DAYTIME
CONDITIONS, ADDING TO THE HEAT IMPACTS.
INCREASING ONSHORE FLOW WILL CAUSE STRONGER SEA BREEZES EACH
DAY DURING THE AFTERNOON AND EVENING HOURS ACROSS INTERIOR
SECTIONS, INCLUDING THE ANTELOPE VALLEY. THE STRONGEST ONSHORE
WINDS ARE EXPECTED TO BE ON SUNDAY AND MONDAY. THE GUSTY WINDS,
ALONG WITH THE HOT AND DRY CONDITIONS WILL PRODUCE ELEVATED TO
BRIEF CRITICAL FIRE WEATHER CONDITIONS. WITH THE ENHANCED
INSTABILITY OVER THE REGION, THERE IS ALSO AN INCREASED RISK OF
LARGE VERTICAL PLUME GROWTH WITH ANY NEW FIRES ACROSS THE INTERIOR
THIS WEEKEND.
LONG TERM (WED-SAT)
09/229 AM.
THE RIDGE OF HIGH PRESSURE WILL FINALLY MOVE EASTWARD AND WEAKEN
AS AN INCOMING TROUGH STARTS TO MOVE INTO THE WEST COAST ON
TUESDAY INTO WEDNESDAY. AT THE SAME TIME, AN UPPER LEVEL
LOW/DISTURBANCE WILL SIT OFF THE CENTRAL COAST MID-WEEK, GETTING
ABSORBED BY THE TROUGH AND POTENTIALLY LINGERINGERING INTO LATE
FRIDAY. AT THE SAME TIME, ONSHORE FLOW WILL INCREASE BOTH TO THE
NORTH AND THE EAST BECOMING STRONGLY ONSHORE IN BOTH DIRECTIONS
DURING THE AFTERNOONS. THE INCREASED ONSHORE FLOW WILL ALLOW THE
MARINE LAYER TO PUSH INTO THE VALLEYS EACH NIGHT THROUGH MORNING.
SLOWER THAN NORMAL CLEARING SKIES WILL BE LIKELY AS THE ONSHORE
FLOW STRENGTHENS, AND SOME WEST FACING BEACHES MAY SEE ONLY
LIMITED CLEARING EACH AFTERNOON AND EVENING. THE COMBINATION OF A
DEEPER MARINE LAYER, STRONGER ONSHORE FLOW, AND FALLING HEIGHTS
WILL BRING COOLING TUESDAY THROUGH THURSDAY. MAXIMUM TEMPS WILL
LARGELY BE BELOW NORMAL BY WEDNESDAY AND THURSDAY.
PWS WILL REMAIN ELEVATED THROUGH THE PERIOD, HOWEVER. IN
COMBINATION WITH WARMER THAN NORMAL OCEAN TEMPERATURES OFF THE
IMMEDIATE COAST, CONDITIONS WILL CONTINUE TO FEEL A LITTLE
MORE HUMID THAN NORMAL. IT WILL ALSO KEEP OVERNIGHT LOWS A LITTLE
WARMER THAN NORMAL. THE REGION WILL REMAIN ON THE FRINGE OF THE
MONSOONAL MOISTURE THROUGH AT LEAST WEDNESDAY, WITH THE ELEVATED
MOISTURE AND INCREASED INSTABILITY KEEPING THE LOW CHANCE (10 TO
15 PERCENT) OF AFTERNOON MOUNTAIN CONVECTION GOING. IN THE
THURSDAY-FRIDAY TIME FRAME, MEDIUM-RANGE MODELS CONTINUE TO
INDICATE THE POTENTIAL FOR AN UPPER LOW TO DEVELOP OFF THE
CENTRAL CALIFORNIA COAST, EAST OF WHICH LARGE-SCALE ASCENT AND
CONVECTIVE CHANCES COULD MODESTLY INCREASE SOMETIME BETWEEN
THURSDAY AND FRIDAY. AT THIS TIME, THE CONVECTIVE CHANCES
ARE STILL IN THE 5-15 PERCENT RANGE ACROSS THE AREA, WITH THE
HIGHEST CHANCES FOCUSED ACROSS THE CENTRAL COAST. LATEST
ECMWF ENSEMBLE DATE SHOWING A WEAK CONVECTIVE SIGNAL IN THAT
THURSDAY-FRIDAY TIME FRAME WITH A SLIGHTLY UPTICK IN MUCAPE
VALUES. IF CONVECTION WERE TO DEVELOP, THE MAIN CONCERN WOULD BE
THE POTENTIAL FOR ISOLATED DRY LIGHTNING STRIKES WITH MINIMAL
RAINFALL, ADDING TO THE FIRE WEATHER THREAT. THIS WILL NEED TO BE
MONITORED CLOSELY ESPECIALLY CONSIDERING THE DRY FUELS IN PLACE
AFTER THIS PROLONGED HEATWAVE.
ADDITIONALLY, THE STRONG ONSHORE FLOW TO THE EAST WILL PRODUCE
NEAR ADVISORY LEVEL WIND GUSTS ACROSS THE WESTERN ANTELOPE VALLEY
AND THE WESTERN FOOTHILLS EACH AFTERNOON AND EVENING. GUSTY
SUNDOWNER WINDS WILL ALSO BE POSSIBLE EARLY THIS WEEK IN SOUTHERN
SANTA BARBARA COUNTY.
AVIATION
09/0953Z.
AT 0600Z AT KLAX, THE MARINE LAYER WAS 1000 FEET DEEP. THE TOP OF
THE INVERSION WAS AT 3100 FEET WITH A TEMPERATURE OF 30 C.
HIGH CONFIDENCE IN VFR TAFS FOR KPRB, KBUR, KVNY, KPMD & KWJF.
LOW TO MODERATE CONFIDENCE IN REMAINING TAFS THROUGH 16Z, WITH
LOWEST CONFIDENCE FOR SITES SOUTH OF POINT CONCEPTION. MID- LEVEL
MOISTURE AND WARM SSTS WILL DISRUPT THE FORMATION OF MARINE
LAYER CLOUDS. THIS WILL LIKELY RESULT IN INTERMITTENT CIGS
ESPECIALLY FOR KLAX, KSMO, & KLGB. CIG HEIGHTS ACCURATE WITHIN +/-
200 FT OF CURRENT FORECAST.
KLAX...FAIR CONFIDENCE IN TAF. INTERMITTENT CIGS (007-010)
POSSIBLE THROUGH 15Z SUN. NO SIGNIFICANT EAST WIND COMPONENT
EXPECTED.
KBUR...HIGH CONFIDENCE IN VFR TAF. NO WIND ISSUES EXPECTED.
MARINE
09/201 AM.
CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY (SCA) ACROSS
THE COASTAL WATERS THROUGH AT LEAST WEDNESDAY NIGHT. THE ONLY
EXCEPTION IS A 20% CHANCE OF SCA LEVEL NW WINDS ACROSS THE EXTREME
NORTHWEST PORTION OF THE OUTER WATERS NORTH OF POINT SAL (PZZ676)
THIS AFTERNOON AND EVENING.
DENSE FOG MAY AFFECT PORTIONS OF THE COASTAL WATERS THROUGH THIS
MORNING AND POSSIBLY THE NEXT NIGHT THROUGH MORNING PERIODS
THROUGH TUESDAY.
BEACHES
09/201 AM.
HIGH ASTRONOMICAL TIDES ARE EXPECTED TO AFFECT LOW-LYING BEACHES
SOUTH OF POINT CONCEPTION WITH THE POSSIBILITY OF MINOR COASTAL
FLOODING STARTING WITH THE EVENING HIGH TIDE ON MONDAY AND
CONTINUING THROUGH AT LEAST WEDNESDAY. AS A RESULT, A COASTAL
FLOOD ADVISORY HAS BEEN ISSUED.
PREDICTED TIDE HEIGHTS OF UP TO 7.5 FEET ARE EXPECTED BETWEEN
ABOUT 8 AND 10 PM EACH EVENING. THESE TIDES, COMBINED WITH A SMALL
INCREASE IN A LONG-PERIOD SOUTHERLY SWELL, COULD RESULT IN MINOR
FLOODING OF SEA WATER AROUND THE TIME OF HIGH TIDE OVER LOW-LYING
COASTAL AREAS SUCH AS PARKING LOTS, BEACHES, AND WALKWAYS. BEACHES
MOST SUSCEPTIBLE TO POTENTIAL MINOR COASTAL FLOODING ISSUES
INCLUDE THOSE AROUND POINT DUME AND NEAR LONG BEACH.
LOX WATCHES/WARNINGS/ADVISORIES
CA...EXTREME HEAT WARNING IN EFFECT UNTIL 8 PM PDT THIS EVENING
FOR ZONES 38-377-381>383. (SEE LAXNPWLOX).
HEAT ADVISORY IN EFFECT UNTIL 8 PM PDT THIS EVENING FOR ZONES
88-342>345-348-349-351>353-356>358-367>376-378>380-548. (SEE LAXNPWLOX).
COASTAL FLOOD ADVISORY IN EFFECT FROM 6 PM MONDAY TO MIDNIGHT
PDT WEDNESDAY NIGHT FOR ZONES 349-350-354-362-366. (SEE LAXCFWLOX).
PZ...NONE.
PUBLIC...KL/GOMBERG
AVIATION...LUND
MARINE...KL/BLACK
BEACHES...SIRARD
SYNOPSIS...KL/COHEN/CILIBERTI
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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