063
FXUS66 KSGX 190937
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
237 AM PDT SUN JUL 19 2026
SYNOPSIS
NEAR SEASONAL TEMPERATURES THROUGH THE FIRST HALF OF THE WEEK
FOLLOWED BY MINOR WARMING WEDNESDAY THROUGH SUNDAY. CHANCES FOR
AFTERNOON SHOWERS REMAIN CONFINED TO THE HIGHER MOUNTAIN PEAKS
THROUGH WEDNESDAY, WITH THE POTENTIAL FOR MORE WIDESPREAD SHOWER
AND THUNDERSTORM ACTIVITY FOR THE LATTER HALF OF NEXT WEEK. THE
MARINE LAYER WILL REMAIN MOSTLY CONFINED TO THE COAST, REACHING
INTO PORTIONS OF THE VALLEYS AT TIMES.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
..UPDATED AVIATION DISCUSSION
MARINE LAYER LOW CLOUDS CONTINUE TO FILL IN ALONG THE COAST AND UP
TO 10 MILES INLAND THIS MORNING, OTHERWISE JUST A FEW MID LEVEL
CLOUDS ARE MOVING WEST FROM EARLIER CONVECTION OVER AZ. LOW CLOUDS
WILL CLEAR BY LATE MORNING. THE 00Z KNKX SOUNDING SHOWS
PRECIPITABLE WATER HAD DECREASED TO AROUND 1.5" WITH STABLE
CONDITIONS. ENSEMBLES SHOW LITTLE CHANGE IN MOISTURE AND
INSTABILITY TODAY AND MONDAY, WITH ANY SHOWERS LIMITED TO THE
HIGHER PEAKS OF THE SAN BERNARDINO MOUNTAINS (15% CHANCE) AND
THUNDERSTORM CHANCES ARE LESS THAN 10%. MOISTURE DECREASES
SLIGHTLY ON TUESDAY FOR EVEN LOWER CHANCES OF SHOWERS AND
THUNDERSTORMS (10% OR LESS).
AN UPPER LEVEL HIGH REMAINS OVER THE CENTRAL ROCKIES INTO TUESDAY
WITH LITTLE DAY TO DAY CHANGES IN THE WEATHER OVER SO CAL. HIGH
TEMPERATURES WILL BE NEAR SEASONAL AVERAGES - GENERAL MID TO UPPER
70S AT THE BEACHES TO MID 80S TO MID 90S IN THE VALLEYS, UPPER 70S
TO MID 80S IN THE MOUNTAINS, MID 90S TO AROUND 100 IN THE HIGH
DESERT, AND 100-110 IN THE LOW DESERT. AREAS OF NIGHT AND MORNING
LOW CLOUDS WILL CONTINUE ALONG THE COAST AND INTO THE FAR WESTERN
VALLEYS.
FOR THE LATTER HALF OF THE WEEK, THE UPPER LEVEL HIGH SHIFTS SOUTH
TOWARDS OK/TX WED-THU AND THEN SLOWLY SHIFTS WESTWARD INTO NEXT
WEEKEND. ENSEMBLES CONTINUE TO SHOW AN INCREASE IN PW DURING THIS
PERIOD, AS WELL AS INCREASING MUCAPE OVER THE MOUNTAINS. HOWEVER,
ENSEMBLES ARE ALSO SHOWING THE EAST-WEST RIDGE AXIS DIRECTLY
OVERHEAD, WHICH WOULD HELP SUPPRESS CONVECTION DURING THE
AFTERNOONS. NBM POPS HAVE TRENDED DOWNWARDS FOR THURSDAY (15-30%
CHANCE OVER THE MOUNTAINS) BUT REMAIN HIGHER FOR FRIDAY (25-40%
CHANCE). WARMING IS MORE CERTAIN, ESPECIALLY WEST OF THE
MOUNTAINS, FOR THE LATTER HALF OF THE WEEK WITH HIGH TEMPERATURES
INCREASING TO AROUND 5 DEGREES ABOVE NORMAL. LESS CERTAINTY IN THE
LOW DESERTS AS ANY LOW-LEVEL MOISTURE SURGES WILL KEEP DAYTIME
TEMPERATURES LOWER - NOT THAT IT WILL FEEL ANY BETTER WITH AN
INCREASE IN HUMIDITY. OTHERWISE A SHALLOWER MARINE LAYER WITH THE
POTENTIAL FOR PATCHIER CLOUD COVER DURING THE NIGHTS AND MORNINGS.
AVIATION
190930Z....COAST/VALLEYS...LOW CLOUDS BASED 1100-1500 FT MSL ARE
COVERING MOST OF THE SD/OC LOWLANDS UP TO 20 MILES INLAND, THOUGH
STILL PATCHY IN SPOTS. VIS RESTRICTIONS WHERE CLOUDS INTERSECT
TERRAIN AND IN ELEVATED EASTERN VALLEY SITES LIKE KRNM. BR/HZ (VIS 4-
6SM) LOCALLY IN WESTERN PARTS OF THE INLAND EMPIRE 12-16Z. LOW
CLOUDS SCATTER OUT 15-16Z WITH FEW-SCT CLOUDS REMAINING ABOVE 10 KFT
MSL AND VFR PREVAILING. LOW CLOUDS WITH SIMILAR BASES RETURN TO THE
COAST 02-05Z MON, REACHING INTO OC 06-08Z.
MOUNTAINS/DESERTS
VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH
FEW-SCT MID-LEVEL CLOUDS GENERALLY AOA 15,000FT MSL. FEW-SCT CU
BASED 10-12 KFT MSL MAY DEVELOP OVER THE MOUNTAIN RIDGETOPS SUNDAY
AFTERNOON, WITH A SMALL (10%) CHANCE FOR ISO SHRA/TSRA, MOST LIKELY
AFTER 21Z THROUGH 01Z MON.
OTHERWISE, WEST WINDS GUSTING 20-35 KTS ALONG DESERT SLOPES
02-09Z MON (UP TO 45 KTS THROUGH THE BANNING PASS).
MARINE
WEDNESDAY AFTERNOON, THERE IS AROUND A 50% CHANCE FOR NORTHWESTERLY
WIND GUSTS TO EXCEED 20 KTS IN THE OUTER WATERS NEAR SAN CLEMENTE
ISLAND. OTHERWISE, NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED
THROUGH THURSDAY MORNING.
BEACHES
HIGH AMPLITUDE SOUTHERLY SWELL (4-5 FT WITH A PERIOD OF 11-13
SECONDS) WILL BUILD TODAY, BRINGING ELEVATED TO HIGH SURF AND STRONG
RIP AND LONGSHORE CURRENTS THROUGH AT LEAST TUESDAY. HIGHEST SURF,
UP TO 7-8 FT, WILL BE ALONG SOUTH AND SOUTHWEST-FACING BEACHES.
FURTHER DETAILS CAN BE FOUND IN THE HIGH SURF ADVISORY. SURF FALLS A
BIT TUESDAY AND INTO WEDNESDAY BEFORE ANOTHER SOUTHERLY SWELL (4-5
FT WITH A PERIOD OF ~15 SECONDS) BRINGS ANOTHER ROUND OF ELEVATED TO
HIGH SURF FOR THE END OF THE WEEK AND INTO THE EARLY WEEKEND. THE
HIGH RISK FOR STRONG RIP CURRENTS WILL REMAIN THROUGH THE END OF THE
WEEK.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...HIGH SURF ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM PDT TUESDAY
FOR ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL
AREAS.
PZ...NONE.
PUBLIC...SS
AVIATION/MARINE/BEACHES...WESTERINK
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