876
FXUS66 KLOX 171737
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1037 AM PDT FRI JUL 17 2026
SYNOPSIS
17/306 AM.
A FEW DEGREES OF COOLING ARE EXPECTED TODAY WITH TEMPERATURES
RETURNING TO NORMAL OVER THE WEEKEND. MORNING LOW CLOUDS AND FOG
WILL RETURN TO MANY COASTAL AREAS TODAY AND EACH DAY THROUGH
EARLY NEXT WEEK. A WARMING TREND IS EXPECTED BY THE MIDDLE OF NEXT
WEEK AS UPPER LEVEL HIGH PRESSURE BUILDS INTO THE AREA.
SHORT TERM (TDY-SUN)
17/300 AM.
NOT MUCH CHANGE IN THE UPPER LEVEL PATTERN OVER SRN CA TODAY 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 (10%) OF A SHOWER OR THUNDERSTORM ESPECIALLY IN THE
VTU/L.A. COUNTY MTNS. EVEN SO, IT LOOKS LIKE THE BULK OF THE
MONSOONAL MOISTURE WILL REMAIN EAST OF L.A. COUNTY THRU SUN.
PRESSURE GRADIENTS WILL BE ONSHORE AND INCREASE OVER THE NEXT
COUPLE OF DAYS. THIS WILL PROMOTE COOLER TEMPS FROM THE RECENT
VERY HOT WEATHER, ALONG WITH AN INCREASE IN COASTAL NIGHT AND
MORNING LOW CLOUDS AND FOG. OVERALL, IT LOOKS LIKE TEMPS WILL BE
NEAR NORMAL TO SEVERAL DEGREES BELOW NORMAL ACROSS THE REGION
TODAY THRU SUN. 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 (MON-THU)
17/303 AM.
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. BY WED,
AFTERNOON HIGHS ARE FORECAST TO TOP OUT AROUND 100 DEGREES FOR
THE WARMEST VLYS AND LOWER MTNS, WITH 80S EDGING CLOSER TO THE
COAST. WITH POTENTIALLY WEAKER ONSHORE PRESSURE GRADIENTS FOR WED
AND THU, HIGH TEMPS COULD ACTUALLY WIND UP BEING A FEW DEGREES
WARMER THAN IS CURRENTLY FORECAST.
AVIATION
17/1736Z.
AT 1700Z AT KLAX, THE MARINE LAYER WAS 2000 FT DEEP. THE TOP OF
THE INVERSION WAS AT 4500 FT WITH A MAX TEMPERATURE OF 23 C.
HIGH CONFIDENCE IN VFR TAFS FOR KPMD AND KWJF.
LOW CONFIDENCE KPRB, KBUR, AND KVNY. THERE IS A 30% CHANCE FOR
IFR CONDS AT KPRB AFTER 10Z. THERE IS A CHANCE VFR CONDS PREVAIL
AT KBUR (40%) AND KVNY (50%). IF CIGS DO ARRIVE, LOWER CONFIDENCE
IN TIMING OF CIG WHICH COULD BE UP TO 4 HOURS EARLIER THAN
FORECAST, AND MIN CIG HEIGHT MAY BE OFF BY +/- 300 FEET.
MODERATE CONFIDENCE IN REMAINING TAFS. CIGS EXPECTED AT EACH SITE,
EXCEPT FOR A 25% CHANCE NO LOW CLOUDS AT KSBP TONIGHT. FLIGHT CAT
CHANGES MAY BE OFF BY 3 HOURS, WITH LOWEST CONFIDENCE IN TIME FOR
KSBP AND KSBA. MIN CIG HEIGHTS MAY BE OFF BY +/- 200 FEET.
KLAX...MODERATE CONFIDENCE IN TAF. ARRIVAL OF CIGS MAY BE AS EARLY
AS EARLY AS 01Z OR AS LATE AS 06Z. 10% CHANCE FOR BRIEF
OVC008-009 CIGS BEFORE 10Z. 30% CHANCE OF AN EAST WIND COMPONENT
REACHING 6 KT OVERNIGHT INTO SAT MORNING.
KBUR...LOW CONFIDENCE IN TAF AFTER 06Z. 40% CHANCE VFR CONDS
PREVAIL. IF CIGS DO ARRIVE, LOWER CONFIDENCE IN TIMING OF CIG
WHICH COULD BE UP TO 4 HOURS EARLIER THAN FORECAST, AND MIN CIG
HEIGHT MAY BE OFF BY +/- 300 FEET.
MARINE
17/929 AM.
FOR THE OUTER WATERS, MARGINAL SMALL CRAFT ADVISORY (SCA) LEVEL
WINDS ARE LIKELY TO PERSIST FOR THE MOST PART THROUGH LATE
TONIGHT, THEN WINDS AND SEAS WILL LARGELY BE BELOW SCA LEVELS
ACROSS THESE WATERS SATURDAY THROUGH TUESDAY NIGHT. SOME LOCALIZED
AREAS MAY SEE WINDS REACH SCA LEVELS AT TIMES DURING THE PERIOD.
FOR THE INNER WATERS N OF POINT SAL, MARGINAL SCA LEVEL WINDS WILL
OCCUR THIS AFTERNOON AND EVENING, THEN WINDS AND SEAS ARE LIKELY
TO REMAIN BELOW SCA LEVELS THROUGH THE REMAINDER OF THE FORECAST
PERIOD.
FOR THE SOUTHERN INNER WATERS, CONDITIONS WILL LARGELY REMAIN
BELOW SCA LEVELS THROUGH THE FORECAST PERIOD, EXCEPT OVER THE
WESTERN SBA CHANNEL THERE IS A 20% CHANCE OF SCA WIND GUSTS SUNDAY
EVENING AND A 40% CHANCE OF SCA WIND GUSTS TUESDAY EVENING.
BEACHES
17/928 AM.
OVER THE EASTERN PACIFIC, TROPICAL STORM ELIDA IS STILL FORECAST
TO STRENGTHEN TO HURRICANE STATUS TODAY OR TOMORROW. IT IS
EXPECTED TO MOVE TO THE NORTH AND WEST WELL OFF THE BAJA COAST.
ANOTHER TROPICAL DISTURBANCE IS EXPECTED TO STRENGTHEN NEXT WEEK
AND GENERALLY FOLLOW THE PATH OF ELIDA TO THE NORTHWEST. THESE
TROPICAL SYSTEMS WILL PRODUCE GENERALLY 10-15 SECOND PERIOD
SOUTHERLY SWELLS, WHICH WILL PROPAGATE NORTHWARD AND BEGIN
AFFECTING SOUTH-FACING BEACHES AS EARLY AS SUNDAY EVENING. WHILE
THERE IS QUITE A BIT OF UNCERTAINTY IN TIMING AND EXACT MAGNITUDE
OF THESE SWELLS, IT IS LIKELY THAT HAZARDOUS CONDITIONS WILL
PREVAIL AT THE BEACHES FOR MUCH OF NEXT WEEK.
ADDITIONALLY, A LONG PERIOD SOUTHERN HEMISPHERE SOUTH SWELL IS
FORECAST TO ARRIVE SOMETIME LATE NEXT WEEK, LIKELY CONTRIBUTING TO
CONTINUED AND POTENTIALLY MORE HAZARDOUS BEACH CONDITIONS INTO
THE FOLLOWING WEEKEND.
LOX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT FROM 3 PM THIS AFTERNOON TO 10
PM PDT THIS EVENING FOR ZONE 645. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PDT SATURDAY FOR
ZONES 670-673-676. (SEE LAXMWWLOX).
PUBLIC...SIRARD
AVIATION...LEWIS
MARINE...LEWIS
BEACHES...LEWIS
SYNOPSIS...SIRARD
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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