116
FXUS66 KSGX 162045
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
145 PM PDT FRI MAY 16 2025
SYNOPSIS
COOLER CONDITIONS WITH INCREASED WINDS AND CLOUD COVERAGE EXPECTED
OVER THE WEEKEND. LOW CLOUDS ARE EXPECTED TO FILL IN MUCH OF THE
COASTAL BASIN EACH NIGHT AND MORNING. THERE ARE CHANCES OF LIGHT
RAIN AND DRIZZLE WEST OF THE MOUNTAINS TONIGHT INTO SATURDAY AND
SATURDAY NIGHT INTO SUNDAY. WARMER CONDITIONS WITH A SHALLOWER
MARINE LAYER IS EXPECTED FOR NEXT WEEK.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
A TROUGH OF LOW PRESSURE WILL START TO DIG INTO THE PACIFIC
NORTHWEST LATER TONIGHT. CROSS SECTIONS OF OUR LOCAL WRF ARE
INDICATING A FAIRLY DEEP SATURATED LAYER FOR TONIGHT INTO SATURDAY
MORNING. CURRENT INDICATIONS ARE THIS LAYER WILL BE SATURATED ENOUGH
TO PRODUCE AREAS OF DRIZZLE OR LIGHT RAIN WEST OF THE MOUNTAINS AND
ON MOUNTAIN SLOPES DURING THAT TIME. MINIMAL ACCUMULATIONS ARE
EXPECTED WITH CHANCES OF RAINFALL TOTALS REACHING OR EXCEEDING 0.10"
AT 5 PERCENT OR LESS.
AS THE LOW PRESSURE SYSTEM BEGINS TO DIG SOUTH INTO THE GREAT BASIN
SATURDAY AFTERNOON AND EVENING, RAIN CHANCES INCREASE ESPECIALLY FOR
SAN DIEGO COUNTY. ANY RAINFALL IS EXPECTED TO BE LIGHT, BUT MORE
WIDESPREAD ACROSS THE COASTAL BASIN COMPARED TO WHAT IS EXPECTED
TONIGHT INTO SATURDAY MORNING. IT'S UNLIKELY RAINFALL TOTALS WILL
EXCEED 0.20" FOR THE COAST AND VALLEYS AND 0.40" FOR THE COASTAL
MOUNTAIN SLOPES. THE MOST LIKELY PLACES FOR ACCUMULATING RAINFALL
ARE IN THE SAN DIEGO COAST, VALLEYS, AND MOUNTAINS.
STRONGER, GUSTY SOUTHWEST TO WEST WINDS ARE EXPECTED FOR THE DESERT
SLOPES OF THE MOUNTAINS AND DESERTS FOR SATURDAY AFTERNOON INTO
SATURDAY NIGHT. STRONGER GUSTS OF 45 TO 55 MPH WITH ISOLATED GUSTS
TO 70 MPH IN THE NORTHERN COACHELLA VALLEY BELOW THE SAN GORGONIO
PASS ARE EXPECTED. GUSTY WEST WINDS WILL CONTINUE SUNDAY AFTERNOON
AND EVENING BUT NOT QUITE AS STRONG WITH GUSTS TO 40 TO 50 MPH AND
ISOLATED GUSTS TO 65 MPH THROUGH WIND PRONE PASSES.
HIGH PRESSURE WILL BRING DRY WEATHER WITH WARMING MONDAY THROUGH
THURSDAY. CONDITIONS WILL WARM QUITE RAPIDLY BETWEEN SUNDAY AND
MONDAY, ESPECIALLY IN THE VALLEYS AND MOUNTAIN FOOTHILLS DUE TO A
BRIEF PERIOD OF OFFSHORE WINDS. HIGHS IN THE VALLEYS AND FOOTHILLS
WILL BE UP TO 10 DEGREES WARMER ON MONDAY COMPARED TO SUNDAY. AS
EARLY AS TUESDAY, HIGHS ALONG THE COAST AND VALLEYS WILL BE 10 TO 15
DEGREES ABOVE AVERAGE. THE WARMING WILL SPREAD FURTHER INLAND FOR
WEDNESDAY AND THURSDAY. FOR WEDNESDAY AND THURSDAY, NBM CHANCES FOR
HIGH TEMPERATURES IN THE WARMER PORTIONS OF THE INLAND EMPIRE TO
EXCEED 100 ARE AROUND 45 TO 55 PERCENT WITH NBM CHANCES FOR THE
WARMER PORTIONS OF THE LOWER DESERTS TO EXCEED 110 ON THURSDAY AT 5
TO 10 PERCENT. THE MARINE LAYER WILL BECOME SHALLOWER WITH NIGHT AND
MORNING COASTAL LOW CLOUDS NOT EXTENDING INLAND PAST THE FAR WESTERN
VALLEYS FOR WEDNESDAY AND THURSDAY.
AVIATION
162030Z...COAST/VALLEYS...LOW CLOUDS HAVE MOSTLY CLEARED THIS
AFTERNOON WITH ONLY FEW-SCT COVERAGE BASED NEAR 2000 FT MSL
LINGERING ACROSS PORTIONS OF THE COASTS. LOW CLOUDS BASED NEAR 1500-
2000 FT MSL FILL BACK IN AND PUSH ASHORE AFTER 02Z, FILLING THE
ENTIRE COASTAL BASIN TO THE FOOTHILLS BY 09-11Z. PATCHY DRIZZLE IS
POSSIBLE ACROSS THE COASTS AND THE WESTERN VALLEYS BETWEEN 08-18Z
AND MAY LINGER INTO THE AFTERNOON ALONG THE COASTS. DRIZZLE MAY
LOCALLY LOWER VIS TO 4-6 SM AND CIGS NEAR 1000-1500 FT.
MOUNTAINS/DESERTS...SCT HIGH CLOUDS LATE TODAY AND TONIGHT. AFTER
22Z, POCKETS OF WESTERLY SURFACE WINDS INCREASE TO 25-30 KNOTS WITH
GUSTS TO 40 KNOTS THROUGH MOUNTAIN PASSES INTO ADJACENT DESERTS.
THIS COULD PRODUCE INTERMITTENT STRONG UP/DOWNDRAFTS IN THE LEE OF
MOUNTAINS SUCH AS VCNTY KPSP.
MARINE
ONSHORE WINDS GUSTING NEAR 20 KTS LATE SATURDAY INTO EARLY SUNDAY
MAY LEAD TO SOME CHOPPY SEAS IN THE OUTER WATERS NEAR SAN CLEMENTE
ISLAND FOR SATURDAY EVENING. OTHERWISE, NO HAZARDOUS MARINE
CONDITIONS EXPECTED THROUGH WEDNESDAY.
BEACHES
ELEVATED SURF WILL IMPACT BEACHES SUNDAY AND MONDAY. EXPECTED SURF
OF 4-6 FEET WOULD PRODUCE A HIGH RIP CURRENT RISK.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...WIND ADVISORY FROM NOON SATURDAY TO 2 AM PDT SUNDAY FOR APPLE
AND LUCERNE VALLEYS-RIVERSIDE COUNTY MOUNTAINS-SAN
BERNARDINO COUNTY MOUNTAINS-SAN DIEGO COUNTY DESERTS-SAN
DIEGO COUNTY MOUNTAINS-SAN GORGONIO PASS NEAR BANNING.
PZ...NONE.
PUBLIC...CO
AVIATION/MARINE/BEACHES...MUNYAN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page