417
FXUS66 KLOX 180524
AFDLOX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1024 PM PDT FRI JUL 17 2026
UPDATED AVIATION SECTION
SYNOPSIS
17/832 PM.
TEMPERATURES ARE EXPECTED TO CHANGE LITTLE OVER THE NEXT FEW DAYS,
AND MOST AREAS WILL BE NEAR NORMAL. MORNING LOW CLOUDS AND FOG
WILL RETURN TO MANY COASTAL AREAS EACH NIGHT TO MORNING PERIOD
THROUGH EARLY NEXT WEEK. A WARMING TREND IS EXPECTED BY THE MIDDLE
OF NEXT WEEK AS UPPER LEVEL HIGH PRESSURE BUILDS INTO THE AREA
WHILE ONSHORE GRADIENTS WEAKEN.
SHORT TERM (FRI-MON)
17/831 PM.
***UPDATE***
PRELIMINARY RECORD:
A RECORD HIGH TEMPERATURE OF 86 DEGREES WAS SET AT LOS ANGELES
AIRPORT TODAY. THIS BREAKS THE OLD RECORD OF 85 DEGREES SET IN 2003.
====================================================================
MINOR CHANGES IN PRESSURE GRADIENTS AND HEIGHTS WILL LIKELY RESULT
IN SIMILAR MARINE LAYER COVERAGE AS LAST NIGHT AND THIS MORNING.
PERHAPS A LITTLE BIT MORE NORTHWARD EXTENT ACROSS THE LA BASIN.
30% CHANCE THAT STRATUS BRIEFLY REACHES EASTERN SAN FERNANDO
VALLEY (BURBANK AREA) DURING THE EARLY MORNING HOURS. EXPECTING
THE MARINE LAYER TO BEHAVIOR SIMILARLY THROUGH THE WEEKEND.
NO WIND ISSUES THROUGH SHORT-TERM. 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).
BY SUNDAY AFTERNOON, WEAK MID-LEVEL PERTURBATIONS COULD TAP INTO
MONSOONAL MOISTURE RESULTING IN A NON-ZERO (5-10%) CHANCE OF A
SHOWER OR EVEN A THUNDERSTORM ACROSS THE HIGH TERRAIN OF VTU/L.A
COUNTIES. MOST OF THIS ACTIVITY WILL REMAIN EAST OF OUR CWA IN
MORE CLIMO FAVORED AREAS.
TROPICAL STORM ELIDA IS EXPECTED TO RAPIDLY WEAKEN AS IT MOVES
NORTHWARD WELL OFFSHORE TO THE WEST. THIS WILL RESULT IN MOISTURE
ADVECTION ACROSS THE CENTRAL COAST (PWAT 1.5" OR HIGHER). THE
MOST LIKELY OUTCOME IS MID-UPPER LEVEL CLOUDS WITH NO RAINFALL
SUNDAY/MONDAY ESPECIALLY IF NHC FORECAST REMAINS ON TRACK.
***FROM PREVIOUS DISCUSSION***
NOT MUCH CHANGE IN THE UPPER LEVEL PATTERN OVER SRN CA THRU SUN
WITH THE REGION UNDER THE SW PERIPHERY OF A LARGE WESTERN U.S.
UPPER LEVEL HIGH CENTERED MAINLY BETWEEN WY AND CO. H5 HEIGHTS
OVER THE FORECAST AREA WILL BE GENERALLY IN THE 589-591 DAM RANGE
THRU THE PERIOD. THE UPPER LEVEL FLOW WILL START OUT MOSTLY
SOUTHERLY THRU SAT THEN TURN MORE SE INTO SUN. SOME MONSOONAL
MOISTURE WILL PUSH BACK INTO SW CA THIS WEEKEND WITH AN INCREASE
MID LEVEL CLOUDS AT TIMES, AND BY SUN SOME AFTERNOON CU BUILDUPS
CANNOT BE RULED OUT IN THE MTNS ALONG WITH A NON-ZERO CHANCE
(5-10%) OF A SHOWER OR THUNDERSTORM FOCUSED IN THE VTU/L.A.
COUNTY MTNS WITH ABOUT A 5 PERCENT OF A SHOWER JUST ABOUT ANYWHERE
TONIGHT. EVEN SO, IT LOOKS LIKE THE BULK OF THE MONSOONAL
MOISTURE WILL REMAIN EAST OF L.A. COUNTY THRU SUN. A RAPIDLY
WEAKENING TROPICAL CYCLONE WILL PAST WELL TO THE WEST SUNDAY INTO
MONDAY AND MAY PROVIDE A BUMP IN MOISTURE ACROSS THE REGION
INCLUDING THE CENTRAL COAST BEING CLOSEST TO THE SYSTEM. THE MOST
LIKELY SCENARIO IS A BUMP UP IN MID TO HIGH CLOUDS ESPECIALLY FOR
NORTHERN AREAS, HOWEVER, THERE IS A 5-10 PERCENT CHANCE OF A
SHOWER OR THUNDERSTORM, ESPECIALLY INTO MONDAY.
PRESSURE GRADIENTS WILL BE ONSHORE AND INCREASE OVER THE NEXT
COUPLE OF DAYS. THIS WILL SUPPORT NEAR NORMAL TEMPERATURES ALONG
WITH AN INCREASE IN COASTAL NIGHT AND MORNING LOW CLOUDS AND FOG.
AFTERNOON HIGHS SHOULD RANGE FROM THE 70S TO LOW 80S FOR THE
COAST, MID 80S TO MID 90S FOR THE VLYS AND LOWER MTNS, AND 90S TO
AROUND 100 FOR THE DESERTS.
LONG TERM (TUE-FRI)
17/1224 PM.
THE LARGE WESTERN U.S UPPER LEVEL HIGH CENTER IS FORECAST TO
DRIFT S FROM COLORADO ON MON TO THE AREA AROUND NEW MEXICO AND THE
NORTHERN TEXAS PANHANDLE BY THU. SOUTHWESTERN CA WILL CONTINUE TO
BE ON THE WESTERN PERIPHERY OF THIS LARGE UPPER LEVEL HIGH, WITH
H5 HEIGHTS SLOWLY INCREASING TO 592-594 DAM DURING THE EXTENDED
PERIOD.
THE FLOW ALOFT WILL MOSTLY BE FROM THE SE WITH MONSOONAL MOISTURE
EXPECTED TO CONTINUE TO PUSH INTO THE AREA. PRECIPITABLE WATER
VALUES ARE FORECAST TO BE IN THE 1.25 TO 1.40 INCH RANGE FOR THE
MOST PART WHICH IS ABOUT 150 TO 160 PERCENT OF NORMAL FOR THIS
TIME OF YEAR. ALTHOUGH THE DEEPEST MOISTURE AND INSTABILITY 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. FOR NOW, THERE IS
ONLY A MINIMAL CHANCE OF SHOWERS LATE THU IN THE FCST FOR THE
EASTERN L.A. COUNTY MTNS. OTHERWISE, THERE IS A NON-ZERO CHANCE
(10%) FOR A THUNDERSTORM TO DEVELOP IN THE MTNS ESPECIALLY WED AND
THU. 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 LOOK LIKE VARYING AMOUNTS OF NIGHT AND MORNING
COASTAL LOW CLOUDS AND FOG WILL PREVAIL DURING THE EXTENDED
PERIOD, WITH A WARMING TREND THRU 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. THERE IS A MODERATE (50-60 PERCENT CHANCE) THAT AT LEAST
HEAT ADVISORIES WILL BE NEEDED IN SOME AREAS, INCLUDING POTENTIAL
NEAR THE COAST.
AVIATION
18/0522Z.
AT 0457Z AT KLAX, THE MARINE LAYER WAS 1500 FT DEEP. THE TOP OF
THE INVERSION WAS AT 3400 FT WITH A MAX TEMPERATURE OF 24 C.
HIGH CONFIDENCE IN VFR TAFS FOR DESERT AIRFIELDS (KPMD & KWJF).
LOW TO MODERATE CONFIDENCE IN REMAINING TAFS. TIMING OF CIG/VSBY
RESTRICTIONS MAY BE OFF +/- 2.5 HOURS AND FLIGHT MINIMUMS OFF BY
ONE CATEGORY.
KLAX...LOW TO MODERATE CONFIDENCE IN TAF. ARRIVAL AND CLEARING
TIMES OF CIGS NEAR 012 (+/- 300FT) SHOULD BE ACCURATE WITHIN
+/- 2.5 HOURS OF CURRENT FORECAST. THERE IS A 30% CHC EAST WIND
COMPONENT REACHES 7-8 KNOTS BETWEEN 18/08Z-16Z.
KBUR...MODERATE CONFIDENCE IN TAF. THERE IS A 15% CHANCE OF IFR
CIGS FROM 18/12Z-18Z. OTHERWISE, VFR CONDITIONS WITH NO WIND
ISSUES ARE EXPECTED.
MARINE
17/832 PM.
SMALL CRAFT ADVISORY (SCA) NORTHWEST WINDS (15-25 KT) AND SEAS
WILL IMPACT THE WATERS BEYOND 20 NM FROM SHORE THROUGH TONIGHT.
LOCALIZED GUSTS TO 25 KT MAY OCCUR IN THE FAR WESTERN PORTION OF
THE SANTA BARBARA CHANNEL THROUGH AROUND MIDNIGHT. CONDITIONS ARE
THEN 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. NORTHWEST WINDS WILL BEGIN TO STRENGTHEN
TUESDAY AND SCA CONDITIONS ARE EXPECTED TO OCCUR FROM AROUND
TUESDAY NIGHT 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
17/832 PM.
OVER THE EASTERN PACIFIC, TROPICAL STORM ELIDA IS FORECAST TO MOVE
TO THE NORTH AND WEST WELL OFF THE BAJA 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 SATURDAY FOR
ZONES 670-673-676. (SEE LAXMWWLOX).
PUBLIC...MUNROE/BLACK
AVIATION...BLACK
MARINE...LEWIS/CC
BEACHES...LEWIS/CILIBERTI
SYNOPSIS...LEWIS/CILIBERTI
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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