332
FXUS66 KLOX 171007
AFDLOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
307 AM PDT FRI JUL 17 2026
SYNOPSIS
17/305 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
17/0549Z.
AT 0506Z AT KLAX, THE MARINE LAYER WAS 1200 FT DEEP. THE TOP OF
THE INVERSION WAS AT 3600 FT WITH A MAX TEMPERATURE OF 25 C.
HIGH CONFIDENCE IN VFR TAFS FOR KPRB, KBUR, KVNY, KPMD, AND KWJF.
MODERATE CONFIDENCE IN COASTAL TAFS, WHERE MVFR TO IFR CIGS AND
MVFR VSBYS ARE FORECAST TO RETURN. THERE IS A 40% CHANCE FOR
RESTRICTIONS TO BE OFF BY +/- 2 HOURS IN ONSET AND DISSIPATION
TIMING, AND OFF BY ONE CATEGORY IN MINIMUM RESTRICTION. THERE IS
ALSO A 30% CHANCE THAT NO LOW CLOUDS MAY AFFECT KSMX/KSBP AT ALL
LATER TONIGHT INTO FRI MORNING.
KLAX...MODERATE CONFIDENCE IN TAF. ONSET AND DISSIPATION OF MVFR
TO IFR CIGS IS EXPECTED TO OCCUR WITHIN 2 HOURS OF 11Z-18Z ON
FRIDAY. THERE IS LITTLE CHANCE FOR ANY EAST WIND COMPONENT TO
EXCEED 6 KNOTS THRU THE FCST PERIOD.
KBUR...HIGH CONFIDENCE IN VFR TAF.
MARINE
17/153 AM.
FOR THE OUTER WATERS, SMALL CRAFT ADVISORY (SCA) LEVEL WINDS ARE
EXPECTED 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.
FOR THE INNER WATERS N OF POINT SAL, WINDS AND SEAS ARE LIKELY TO
REMAIN BELOW SCA LEVELS THROUGH THE FORECAST PERIOD.
FOR THE SOUTHERN INNER WATERS, CONDS 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
17/305 AM.
OVER THE EASTERN PACIFIC, TROPICAL STORM ELIDA IS EXPECTED TO
STRENGTHEN TO HURRICANE STATUS TODAY AND MOVE TO THE NORTH AND
WEST WELL OFF THE BAJA COAST. ANOTHER TROPICAL DISTURBANCE IS
EXPECTED TO STRENGTHEN EARLY MONDAY AND GENERALLY FOLLOW THE PATH
OF ELIDA TO THE NORTHWEST.
THESE TROPICAL CYCLONES WILL PRODUCE SOUTHERLY SWELLS WHICH WILL
PROPAGATE NORTHWARD AND BEGIN AFFECTING SOUTH-FACING BEACHES BY
SUNDAY WITH BUILDING LONG PERIOD SURF. THIS ACTIVITY WILL LIKELY
PERSIST THROUGH NEXT WEEK. ADDITIONAL SWELLS WILL LIKELY ARRIVE
LATER NEXT WEEK DUE TO STRONG STORMS ACROSS THE SOUTHERN
HEMISPHERE ADDING TO THE MIX, LIKELY PRODUCING MORE SIGNIFICANT
HAZARDOUS BEACH CONDITIONS AT THAT TIME.
LOX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PDT SATURDAY FOR
ZONES 670-673-676. (SEE LAXMWWLOX).
PUBLIC...SIRARD
AVIATION...SIRARD
MARINE...SIRARD
BEACHES...BLACK/CILIBERTI/SIRARD
SYNOPSIS...SIRARD
WEATHER.GOV/LOSANGELES
EXPERIMENTAL GRAPHICAL HAZARDOUS WEATHER OUTLOOK AT:
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=LOX
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