940
FXUS66 KSGX 161832
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1132 AM 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...
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
161800Z....COAST/VALLEYS...LOW CLOUDS HAVE MOSTLY CLEARED OUT THIS
MORNING, WITH FEW-SCT AND OCCASIONALLY BKN CIGS LINGERING ALONG THE
IMMEDIATE COASTLINE. OTHERWISE, VFR PREVAILS TODAY WITH PERIODS OF
FEW-SCT HIGH CLOUDS AOA 15,000FT MSL AND SOUTHERLY BREEZES.
EXPECTING INITIALLY PATCHY LOW CLOUDS TO BEGIN TO PUSH BACK ASHORE
THIS EVENING AFTER 06Z FRIDAY. LIKELY SIMILAR BASES AND COVERAGE AS
SEEN THIS MORNING, THOUGH CONFIDENCE IS RELATIVELY LOW AS MID-LEVEL
MONSOONAL MOISTURE/CLOUDS MOVE IN OVERNIGHT WHICH MAY LIMIT THE
COVERAGE OF THE MARINE LAYER CLOUDS.
MOUNTAINS/DESERTS
PERIODS OF HIGH CLOUDS AOA 15,000 FT AND VFR
CONDITIONS EXPECTED THROUGHOUT THE PERIOD. SCT CU BASED AROUND
12,000FT MSL ALONG WITH ISO TSRA OVER MOUNTAIN RIDGES THIS AFTERNOON
AFTER 21Z THROUGH ABOUT 03Z FRI.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH MONDAY.
BEACHES
HIGH AMPLITUDE SOUTHERLY SWELL (4-5 FT WITH A PERIOD OF 12-13
SECONDS) WILL BUILD SATURDAY INTO SUNDAY, BRINGING ELEVATED SURF AND
STRONG RIP AND LONGSHORE CURRENTS FOR SUNDAY INTO EARLY NEXT WEEK.
HIGHEST SURF (UP TO 7-8 FT) WILL BE ALONG SOUTH AND SOUTHWEST-FACING
BEACHES.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...HEAT ADVISORY UNTIL 8 PM PDT THIS EVENING FOR ORANGE COUNTY
COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
EXTREME HEAT WARNING UNTIL 8 PM PDT THIS EVENING FOR COACHELLA
VALLEY-ORANGE COUNTY INLAND AREAS-RIVERSIDE COUNTY
MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS-SAN BERNARDINO
AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO
COUNTY DESERTS-SAN DIEGO COUNTY MOUNTAINS-SAN DIEGO COUNTY
VALLEYS-SAN GORGONIO PASS NEAR BANNING-SANTA ANA MOUNTAINS
AND FOOTHILLS.
PZ...NONE.
PUBLIC...APR
AVIATION/MARINE...MUNYAN
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