724
FXUS66 KSGX 170632
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1132 PM PDT THU JUL 16 2026
SYNOPSIS
ONE LAST DAY OF HEAT ALERTS WITH TEMPERATURES COOLING NEAR AVERAGE
BY FRIDAY INTO MUCH OF NEXT WEEK. INCREASING MONSOONAL MOISTURE WILL
MOVE INTO THE REGION THROUGH FRIDAY, WITH ELEVATED CHANCES OVER THE
MOUNTAINS AND LOCALLY INTO THE DESERTS. MOISTURE DECREASES BY THE
WEEKEND INTO THE FIRST HALF OF NEXT WEEK WITH MINOR CHANCES OVER THE
MOUNTAIN RIDGES, INCREASING AGAIN BY LATE NEXT WEEK.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
..UPDATED AVIATION/BEACHES DISCUSSION
PREVIOUS DISCUSSION...ISSUED 1132 AM PDT THU JUL 16 2026...
SHOWERS AND WEAK THUNDERSTORMS ARE SEEN MOVING FROM NE TO SW OVER
ARIZONA AND SE CALIFORNIA. SOME OF THESE SHOWERS MAY REACH THE
LOWER DESERTS BY THE EARLY AFTERNOON. INCREASED MOISTURE AND
INSTABILITY IS SEEN IN OUR SOUNDING FROM THIS MORNING, AIDING IN A
BETTER SET UP FOR STORMS TO POP OVER THE MOUNTAINS. RAIN RATES
MAY NEAR ONE HALF INCH IN SOME CELLS ALONG THE MOUNTAIN DESERT
SLOPES. A SIMILAR ENVIRONMENT IS SEEN ON FRIDAY, WITH ELEVATED
CHANCES OVER THE MOUNTAINS AND LOCALLY INTO THE DESERTS. PRESSURE
HEIGHTS WILL FALL BY FRIDAY INTO THE WEEKEND, PROVIDING SLIGHT
COOLING WITH HIGH AND LOW TEMPERATURES CLOSER TO AVERAGE. THE
MARINE LAYER WILL BE PATCHIER WITH CLOUDS FORMING NEAR THE COAST
NIGHTS AND MORNINGS, WITH BETTER CLEARING EACH AFTERNOON.
HIGH PRESSURE BECOMES CENTERED OVER THE ROCKIES AND CENTRAL PLAINS,
PIVOTING MONSOONAL MOISTURE FURTHER TO THE EAST THIS WEEKEND.
THIS WILL LEAD TO MINIMAL CHANCES FOR PRECIPITATION OVER THE
MOUNTAINS DURING THIS TIME INTO THE FIRST HALF OF NEXT WEEK. THE
PATTERN STAYS FAIRLY SIMILAR THROUGH TUESDAY, KEEPING TEMPERATURES
CLOSER TO AVERAGE WITH A HEALTHY MARINE LAYER NEAR THE COAST AND
FAR WESTERN VALLEYS EACH NIGHT.
MODELS SHOW A SUBTLE INCREASE IN MOISTURE BY NEXT WEDNESDAY,
POTENTIALLY INTO THE LATTER HALF OF NEXT WEEK. LOOKING BEYOND THIS,
MODELS SHOW A BIT OF SPREAD ON THE MONSOONAL MOISTURE FEED. THE
MAJOR FACTOR WILL BE WHERE THE AREA OF HIGH PRESSURE WILL BE PLACED.
SOME MODELS HAVE THIS FURTHER EAST INTO THE SOUTHERN PLAINS, WHICH
WOULD SHUNT MOISTURE FURTHER OUT OF OUR REGION, OR CLOSER TO THE
CENTRAL ROCKIES, WHICH WOULD FAVOR A GREATER MOISTURE SET UP. NBM
SHOWS HIGH TEMPERATURES STICKING NEAR AVERAGE WITH 80S AND 90S FOR
MANY AREAS BELOW 6000 FEET WITH WARMER/COOLER TEMPERATURES FOR THE
LOWER DESERTS AND ALONG THE COASTAL AREAS.
AVIATION
170630Z....COAST/VALLEYS...INITIALLY PATCHY LOW CLOUDS BASED 700-
1000 FT MSL WILL CONTINUE TO SPREAD THROUGH COASTAL AREAS. IMPACTS
ARE EXPECTED AT THE MAJOR COASTAL SITES (KSAN/KCRQ/KSNA) BY 10Z, BUT
CONFIDENCE IN SPECIFIC COVERAGE IS RELATIVELY LOW AS MID-LEVEL
MONSOONAL MOISTURE/CLOUDS MOVE IN OVERNIGHT, WHICH MAY LIMIT THE
COVERAGE OF THE MARINE LAYER CLOUDS. PATCHY MINOR VIS REDUCTIONS (2-
5SM) EXPECTED ALONG ELEVATED COASTAL TERRAIN. LOW CLOUDS WILL CLEAR
TO THE COAST BY 16-17Z, WITH MORE SOUTHERLY BREEZES EXPECTED NEAR
THE COASTLINE FRIDAY AFTERNOON. LOW CLOUDS SIMILAR IN BASES AND
COVERAGE MOVE INTO SOUTH SD COASTAL AREAS AFTER 05Z SAT, MOVING
NORTH AND INLAND THROUGH ABOUT 12Z SAT.
MOUNTAINS/DESERTS
PERIODS OF HIGH CLOUDS AOA 15,000 FT AND VFR
CONDITIONS EXPECTED THROUGHOUT THE PERIOD. SCT CU BASED 10-12 KFT
AND ISO-SCT SHRA/TSRA REDEVELOP OVER THE MTNS FRIDAY AFTERNOON, MOST
LIKELY 20Z FRI THROUGH 01Z SAT. ANY STORMS THAT DEVELOP MAY PRODUCE
LIGHTNING, GUSTY WINDS, AND VIS REDUCTIONS.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH MONDAY.
BEACHES
HIGH AMPLITUDE SOUTHERLY SWELL (4-6 FT WITH A PERIOD OF 12-13
SECONDS) WILL BUILD SATURDAY INTO SUNDAY, BRINGING ELEVATED SURF AND
STRONG RIP AND LONGSHORE CURRENTS FOR SUNDAY THROUGH AT LEAST
TUESDAY. HIGHEST SURF, UP TO 7-9 FT, WILL BE ALONG SOUTH AND
SOUTHWEST-FACING BEACHES.
SGX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.
PUBLIC...SS
AVIATION/MARINE/BEACHES...CSP
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