023
FXUS66 KSGX 310357
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
857 PM PDT WED JUL 30 2025
SYNOPSIS
CONDITIONS WILL CONTINUE TO WARM INTO THE WEEKEND, BRINGING
TEMPERATURES TO NEAR SEASONAL NORMALS. TEMPERATURES WEST OF THE
MOUNTAINS WILL CONTINUE TO BE NEAR AVERAGE INTO EARLY NEXT WEEK,
WITH HIGHS IN THE LOW DESERT UP TO 5 DEGREES ABOVE AVERAGE. LOW
CLOUDS AND FOG WILL SPREAD INTO PORTIONS OF THE WESTERN VALLEYS EACH
NIGHT.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
UPDATE: LATEST SATELLITE IMAGERY SHOWS THAT MOST OF THE COASTAL
AREAS OF SAN DIEGO COUNTY ARE BEGINNING TO FILL IN WITH THE MARINE
LAYER. THIS WILL CONTINUE TO ADVANCE INLAND BY LATER IN THE EVENING,
ALTHOUGH LIKELY NOT PENETRATE AS FAR EASTWARD DUE TO BASES BEING
SLIGHTLY LOWER AND THINNER. THERE COULD BE SOME AREAS OF PATCHY FOG,
ESPECIALLY WITHIN THE VALLEYS WEST OF THE I-15 AND ALONG THE COASTAL
TERRAIN. THERE WILL BE SIMILAR TIMING OF CLEARING OUT TOMORROW
MORNING AND FILLING BACK IN BY LATE AFTERNOON/EVENING. THIS MARINE
LAYER WILL CONTINUE TO BECOME THINNED OUT AND LOWER TO THE SURFACE,
WITH INCREASING CHANCES OF ALSO SEEING PATCHY FOG OUT OVER THE
COASTAL WATERS THROUGHOUT THE NEXT COUPLE OF DAYS AS HIGH
PRESSURE INCREASES AT THE SURFACE OVER THE REGION.
THE OVERALL PATTERN WILL SEE VERY LITTLE CHANGE OVER THE NEXT
WEEK AS THE TROUGHING REMAINS IN PLACE OVER THE EAST PACIFIC
WATERS, AND RIDGING TO THE EAST. THIS WILL ALSO KEEP CONDITIONS
DRY AS SW'LY WINDS AT THE 500 MB LEVEL KEEP ANY MONSOONAL MOISTURE
CONFINED OVER ARIZONA WITH GENERALLY LITTLE FLUCTUATION IN
TEMPERATURES THROUGH THEN, AND RIGHT AROUND THE SEASONAL AVERAGE
FOR THIS TIME OF YEAR. ENSEMBLES CONFIRM THIS, REVEALING NEGATIVE
PWAT ANOMALIES OVER OUR MOUNTAINS THROUGH THE NEXT 10 DAYS,
TRANSLATING TO A MUCH LESSER PROBABILITY OF AFTERNOON THUNDERSTORM
ACTION THROUGH THEN AS WELL. MOREOVER, GIVEN AT HOW SIGNIFICANT
THE NEGATIVE ENSEMBLE PWAT VALUES ARE OVER THE SIERRA MADRE
OCCIDENTAL RANGE IN MEXICO THROUGH 15 DAYS, THIS IS A GOOD
INDICATION THAT THE MONSOONAL FLOW WILL BE SUPPRESSED AND NOT BE
QUICK TO IMPACT OUR REGION ANYTIME IN THE NEAR FUTURE.
(PREVIOUS DISCUSSION SUBMITTED AT 124 PM):
MINIMAL CHANGES IN HIGH TEMPERATURES EXPECTED INTO THE WEEKEND,
KEEPING CONDITIONS NEAR OR SLIGHTLY ABOVE THE SEASONAL AVERAGE.
CHANCES OF THE INLAND EMPIRE REACHING OR EXCEEDING 100 DEGREES IS 25
TO 50 PERCENT ON SATURDAY, AND 40 TO 60 PERCENT CHANCE ON SUNDAY.
CHANCES OF THE LOW DESERT REACHING OR EXCEEDING 110 DEGREES ARE 75
TO 95 PERCENT OVER THE WEEKEND. THE MARINE LAYER WILL FLUCTUATE
BETWEEN 1500 AND 2000 FEET IN DEPTH WITH AREAS OF NIGHT AND MORNING
COASTAL LOW CLOUDS SPREADING INTO PORTIONS OF THE WESTERN VALLEYS
LATE EACH NIGHT THROUGH THE FORECAST PERIOD.
A FEW DEGREES OF COOLING IS EXPECTED FOR MONDAY AND TUESDAY OF NEXT
WEEK. SOME LOCATIONS WEST OF THE MOUNTAINS WILL BE UP TO 5 DEGREES
BELOW AVERAGE EARLY NEXT WEEK. HIGHS ON TUESDAY WILL RANGE FROM THE
LOW TO MID 70S NEAR THE COAST TO THE UPPER 80S TO MID 90S FOR THE
INLAND EMPIRE WITH 105 TO 110 FOR THE LOWER DESERTS. WEDNESDAY WILL
BE A FEW DEGREES WARMER THAN TUESDAY.
AVIATION
310330Z....COASTS/WESTERN VALLEYS...LOW CLOUDS AND PATCHY FOG WITH
BASES 600-1000 FEET MSL ARE LINGERING AT THE COAST THIS EVENING,
SLOWLY CREEPING INLAND THROUGH THE NIGHT HOURS. AFTER 08Z THU, FOG
WILL DEVELOP ALONG COASTAL TERRAIN AND VALLEYS WEST OF I-15 WITH VIS
1-5SM, LOCALLY LESS THAN 1SM. SCATTER OUT THURSDAY AROUND 16-17Z.
WIDESPREAD VFR CONDITIONS EXPECTED THURSDAY AFTERNOON. LOW CLOUDS
WITH SIMILAR BASES START MOVING INLAND AGAIN 04-06Z FRI.
INLAND VALLEYS/MOUNTAINS/DESERTS
MOSTLY CLEAR WITH VFR CONDITIONS
THROUGH THURSDAY.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH MONDAY.
BEACHES
FOR BEACHES AND HARBOR...SMALL WATER LEVEL FLUCTUATIONS WILL
CONTINUE PERIODICALLY THROUGH THIS EVENING FROM THE DIMINISHING
TSUNAMI. THE TSUNAMI ADVISORY WAS CANCELLED AT 520 AM THIS MORNING.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.
UPDATE...STEWEY
PUBLIC...CO
AVIATION/MARINE/BEACHES...WESTERINK
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