042  
FXUS66 KLOX 190429  
AFDLOX  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA  
929 PM PDT SAT JUL 18 2026  
 
UPDATED AVIATION SECTION  
   
SYNOPSIS  
18/757 PM.  
 
TEMPERATURES ARE EXPECTED TO CHANGE LITTLE OVER THE NEXT FEW  
DAYS, AND MOST AREAS WILL REMAIN NEAR NORMAL. MORNING LOW CLOUDS  
AND FOG WILL RETURN TO MANY COASTAL AREAS EACH NIGHT THROUGH  
MORNING INTO EARLY NEXT WEEK. A WARMING TREND IS EXPECTED BY THE  
MIDDLE OF THE WEEK, AS UPPER LEVEL HIGH PRESSURE BUILDS INTO THE  
AREA WHILE ONSHORE GRADIENTS WEAKEN.  
 
 
   
SHORT TERM (SAT-TUE)  
18/852 PM.  
 
***UPDATE***  
 
EXPECTING SIMILAR MARINE LAYER STRATUS COVERAGE ALONG THE  
CENTRAL COAST TONIGHT INTO THE MORNING. LESS CONFIDENT IN  
THE ORGANIZATION AND EXTENT OF STRATUS ACROSS THE SANTA  
BARBARA SOUTH COAST. WILL HAVE TO WATCH IF AN EDDY DEVELOPS  
AND HOW IT EVOLVES OVER THE SANTA BARBARA CHANNEL. STRATUS  
IS EXPECTED TO COVER SOUTHERN PORTIONS OF THE LA BASIN, AND  
UNLIKELY TO REACH THE SAN GABRIEL & SAN FERNANDO VALLEYS - AT  
LEAST FOR A SUBSTANTIAL PERIOD OF TIME. THE MARINE LAYER SHOULD  
CONTINUE TO BEHAVE SIMILARLY THROUGH THE SHORT-TERM PERIOD.  
 
TEMPERATURES WILL REMAIN NEAR NORMAL WITH LITTLE FLUCTUATION  
THROUGH MONDAY. FOLLOWED BY A WARMING TREND TUESDAY, PEAKING  
WEDNESDAY THROUGH FRIDAY - WITH A 60% CHANCE OF HEAT ADVISORIES  
ACROSS SOME INTERIOR AREAS. THE EPS, AIFS-ENS, & GEFS ENSEMBLE  
SUITES ALONG WITH THEIR DETERMINISTIC COUNTERPARTS SUGGEST THAT  
RIDGING WILL CONTINUE & EVEN MAY STRENGTHEN SOME IN THE EXTENDED.  
 
THOUGHTS ON WINDS AND CONVECTION REMAIN ON TRACK. READ SHORT TERM  
DISCUSSION BELOW.  
 
***FROM PREVIOUS DISCUSSION***  
 
THE 500 MB HEIGHTS WILL REMAIN FAIRLY SIMILAR OVER THE REGION  
(AROUND 589-592 DAM) THROUGH MONDAY AS A LARGE/WIDE HIGH PRESSURE  
SYSTEM PERSISTS OVER THE UTAH/COLORADO/WYOMING AREA. MEANWHILE,  
TROPICAL STORM ELIDA IS FORECAST TO MOVE NORTHWARD, WELL OFF THE  
COAST TO THE WEST, AND WEAKEN. UPPER LEVEL FLOW WILL SHIFT FROM  
THE S TODAY TO MORE SE ON SUNDAY WITH ELIDA'S MOVEMENTS AND SLIGHT  
SHIFTS IN THE AFOREMENTIONED HIGH PRESSURE SYSTEM.  
 
SUNDAY AFTERNOON INTO LATE MONDAY MORNING, SOME OF THE MOISTURE  
FROM ELIDA COULD REACH THE CENTRAL COAST, WITH THE MOST LIKELY  
OUTCOME RESULTING IN AN INCREASE IN MID TO HIGH CLOUDS. HOWEVER,  
THERE IS A 5-10 PERCENT CHANCE OF A SHOWER FOR THE CENTRAL COAST  
SUNDAY. AT THE SAME TIME, SLIGHT SHIFTS IN THE HIGH PRESSURE  
SYSTEM TO THE NE, WILL HELP BRING SOME MONSOONAL MOISTURE FROM THE  
SE SUNDAY AFTERNOON THROUGH MONDAY. THIS WILL RESULT IN AN INFLUX  
OF MID TO HIGH LEVEL CLOUDS ACROSS THE REGION, AS WELL AS A 5-10  
PERCENT CHANCE OF A SHOWER OR THUNDERSTORM FOCUSED OVER VENTURA  
AND L.A. COUNTY INTERIOR MOUNTAINS, MAINLY ON MONDAY.  
 
AT THE SURFACE, LITTLE CHANGE IN THE PRESSURE GRADIENTS WILL  
RESULT IN SIMILAR MARINE LAYER COVERAGE EACH NIGHT. THE LITTLE  
CHANGE IN MARINE LAYER CLOUDS, PRESSURE GRADIENTS, AND 500 MB  
HEIGHTS WILL MEAN LITTLE CHANGE IN TEMPERATURES THROUGH THE  
WEEKEND. TEMPERATURES WILL GENERALLY BE NEAR NORMAL, WITH HIGHS  
IN THE 70S TO LOW 80S FOR THE COAST, MID 80S TO MID 90S FOR THE  
VALLEYS AND LOWER MOUNTAINS/FOOTHILLS, AND 90S TO AROUND 100 FOR  
THE DESERTS. THE ONSET OF A WARMING TREND IS EXPECTED ON TUESDAY,  
ADDRESSED IN MORE DETAIL IN THE SUBSEQUENT SECTION.  
 
AS FOR WINDS, GENERALLY SUB-ADVISORY SW WINDS 25 TO 40 MPH CAN BE  
EXPECTED EACH AFTERNOON/EVENING ACROSS THE ANTELOPE  
VALLEY/ADJACENT FOOTHILLS. LOCALIZED TERRAIN ENHANCEMENT COULD  
RESULT IN A FEW AREAS GUSTING TO 45 MPH (I.E LAKE PALMDALE).  
SUNDOWNER WINDS IN SOUTHERN SANTA BARBARA COUNTIES COULD BEGIN TO  
REACH NEAR ADVISORY THRESHOLDS ON TUESDAY.  
   
LONG TERM (WED-SAT)  
18/146 PM.  
 
THE LARGE WESTERN U.S UPPER LEVEL HIGH PRESSURE CENTER IS  
FORECAST TO DRIFT TO THE AREA AROUND NEW MEXICO AND THE NORTHERN  
TEXAS PANHANDLE BY THURSDAY. SOUTHWESTERN CA WILL CONTINUE TO BE  
ON THE WESTERN PERIPHERY OF THIS LARGE UPPER LEVEL HIGH, WITH 500  
MB HEIGHTS SLOWLY INCREASING TO 592-594 DAM DURING THE EXTENDED  
PERIOD.  
 
AS A RESULT, THE FLOW ALOFT WILL MOSTLY BE FROM THE SE, BRINGING  
MONSOON MOISTURE INTO THE REGION THROUGH MUCH OF THE WEEK.  
PRECIPITABLE WATER (PWAT) VALUES ARE FORECAST TO BE 1.25 TO 1.50  
INCHES THROUGH MUCH OF THE WEEK FOR AREAS SOUTH OF POINT  
CONCEPTION AND THROUGH MID-WEEK FOR NORTH OF POINT CONCEPTION.  
THESE PWATS ARE ABOUT 150 PERCENT OF NORMAL FOR THIS TIME OF YEAR.  
ALTHOUGH THE DEEPEST MOISTURE AND IS FORECAST TO REMAIN EAST OF  
L.A. COUNTY DURING THE EXTENDED PERIOD, IT DOES LOOK LIKE THE BEST  
CHANCE OF AFTERNOON CONVECTION WILL COME WEDNESDAY AND THURSDAY  
OVER THE MOUNTAINS OF AT LEAST VENTURA AND L.A. COUNTIES. HOWEVER,  
RIGHT NOW CHANCES REMAIN AROUND 10% FOR THUNDERSTORMS ACROSS THE  
MOUNTAINS, AND ARE TOO LOW TO INCLUDE IN THE OFFICIAL FORECAST AT  
THIS TIME. AS WE DRAW CLOSER TO EARLY NEXT WEEK, WE SHOULD HAVE A  
BETTER IDEA OF THE CHANCE AND EXTENT OF AFTERNOON CONVECTION FOR  
THE MIDDLE OF NEXT WEEK.  
 
OTHERWISE, IT LOOKS LIKE VARYING AMOUNTS OF NIGHT AND MORNING  
COASTAL LOW CLOUDS AND FOG WILL PREVAIL DURING THE EXTENDED  
PERIOD, WITH A WARMING TREND THROUGH THE MIDDLE OF NEXT WEEK.  
MODERATE TO HIGH HEAT RISK MAY EXPAND INTO WEDNESDAY OR THURSDAY  
AS PRESSURE GRADIENTS WEAKEN AND MAYBE TURN LIGHTLY OFFSHORE IN  
THE MORNINGS WITH THE POTENTIAL FOR 500 MB HEIGHTS BUILDING TO  
594-596 DAM. THERE IS A MODERATE CHANCE (AT LEAST 60 PERCENT  
CHANCE) THAT AT LEAST HEAT ADVISORIES WILL BE NEEDED IN SOME  
AREAS, INCLUDING POTENTIALLY NEAR THE COAST, BY WEDNESDAY. ALSO OF  
NOTE, SUNDOWNER WINDS IN SOUTHERN SANTA BARBARA COUNTIES COULD  
REACH NEAR ADVISORY THRESHOLDS INTO WEDNESDAY AND THURSDAY.  
 
 
   
AVIATION  
19/0429Z.  
 
AT 0349Z AT KLAX, THE MARINE LAYER WAS 900 FT DEEP. THE TOP OF  
THE INVERSION WAS AT 2400 FT WITH A MAX TEMPERATURE OF 25 C.  
 
HIGH CONFIDENCE IN VFR TAFS FOR KPMD, KWJF, KBUR, KVNY, & KPRB.  
 
LOW TO MODERATE CONFIDENCE IN REMAINING TAFS. CIG ARRIVAL AND  
CLEARING TIMES MAY BE OFF +/- 3 HOURS AND CIG HEIGHTS OFF BY  
+/- 300 FT.  
 
THERE IS A 50% CHANCE THAT IFR CIGS DO NOT ARRIVE AT KSBA AND  
40% CHANCE FOR KCMA.  
 
KLAX...MODERATE CONFIDENCE IN TAF. ARRIVAL AND CLEARING TIMES OF  
MVFR CIGS 012-015 MAY BE OFF +/- 3 HOURS OF CURRENT FORECAST.  
30% CHANCE CIGS ARRIVE AS IFR 008-010 FOR A COUPLE HOURS BEFORE  
LIFTING TO MVFR. THERE IS A 15% CHANCE CIGS DO NOT ARRIVE OR  
REMAIN INTERMITTENT. NO SIGNIFICANT EAST WIND COMPONENT EXPECTED.  
 
KBUR...MODERATE CONFIDENCE IN TAF. 10% CHANCE FOR IFR CONDS  
BETWEEN 12Z AND 16Z. NO WIND ISSUES EXPECTED.  
 
 
   
MARINE  
18/757 PM.  
 
CONDITIONS ROSE TO SMALL CRAFT ADVISORY (SCA) LEVELS LATE THIS  
AFTERNOON WITH GUSTS OF 25 TO 30 KNOTS ACROSS THE OUTER WATERS AND  
AN ADVISORY WAS ISSUED THROUGH LATE TONIGHT. OTHERWISE, CONDS ARE  
EXPECTED TO REMAIN BELOW SCA LEVELS THROUGH MONDAY EXCEPT FOR  
LOCALIZED SCA LEVEL NORTHWEST WIND GUSTS ACROSS THE OUTER WATERS  
MORE THAN 20 NM FROM SHORE (EXCEPT FOR NEAR POINT CONCEPTION).  
NORTHWEST WINDS WILL BEGIN TO STRENGTHEN TUESDAY, RISING TO SCA  
LEVELS BY WEDNESDAY AND LIKELY TO LAST THROUGH LATE IN THE WEEK.  
 
A SERIES OF MODERATE PERIOD SOUTHERLY SWELLS WILL MOVE THROUGH  
THE WATERS LATE SUNDAY THROUGH MUCH OF NEXT WEEK WHICH MAY IMPACT  
SOUTH FACING HARBORS, INCLUDING THE PORT SAN LUIS AREA.  
 
 
   
BEACHES  
18/757 PM.  
 
OVER THE EASTERN PACIFIC, TROPICAL STORM ELIDA IS FORECAST TO  
MOVE TO THE WEST-NORTHWEST WELL OFF THE BAJA COAST AND EVENTUALLY  
THE CALIFORNIA COAST. ANOTHER TROPICAL DISTURBANCE IS EXPECTED TO  
DEVELOP IN THE SAME AREA AND FOLLOW A SLIGHTLY MORE WESTERLY  
TRACK ALONG 20 N LATITUDE. BOTH SYSTEMS WILL PRODUCE MODERATE  
PERIOD SOUTHERLY SWELLS. HIGH SURF ADVISORIES AND BEACH HAZARDS  
STATEMENTS HAVE BEEN ISSUED ACROSS SOUTHWEST CALIFORNIA FROM  
SUNDAY EVENING THROUGH TUESDAY NIGHT.  
 
THE SECONDARY SYSTEM ON THE HEELS OF ELIDA AND AN INCOMING LONG  
PERIOD SOUTHERN HEMISPHERE SOUTH SWELL ARRIVING LATER NEXT WEEK  
WILL CONTRIBUTE TO CONTINUED AND POTENTIALLY MORE HAZARDOUS BEACH  
CONDITIONS INTO THE FOLLOWING WEEKEND. ADDITIONAL HIGH SURF  
ADVISORIES AND/OR BEACH HAZARDS STATEMENTS ARE LIKELY NEXT WEEK.  
 
 
   
LOX WATCHES/WARNINGS/ADVISORIES  
 
CA...HIGH SURF ADVISORY IN EFFECT FROM 5 PM SUNDAY TO 11 PM PDT  
TUESDAY FOR ZONES 87-354-362-366. (SEE LAXCFWLOX).  
BEACH HAZARDS STATEMENT IN EFFECT FROM SUNDAY AFTERNOON  
THROUGH TUESDAY EVENING FOR ZONES 340-346. (SEE LAXCFWLOX).  
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PDT SUNDAY FOR  
ZONES 670-673-676. (SEE LAXMWWLOX).  
 
 
 
 
 
PUBLIC...LUND/COHEN/BLACK  
AVIATION...BLACK  
MARINE...LEWIS/CILIBERTI  
BEACHES...LEWIS/CC  
SYNOPSIS...LEWIS/CILIBERTI/COHEN  
 
WEATHER.GOV/LOSANGELES  
 
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:  
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX  
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