708
FXUS66 KSGX 191655
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
955 AM PDT MON MAY 19 2025
SYNOPSIS
DRY WEATHER WILL CONTINUE THROUGH NEXT WEEKEND. HIGH TEMPERATURES
FOR THE COAST AND VALLEYS WILL WARM THROUGH WEDNESDAY AND FOR THE
DESERTS THROUGH THURSDAY WITH HIGH TEMPERATURES AROUND 10 DEGREES
ABOVE AVERAGE. THE MARINE LAYER WILL BECOME SHALLOWER THROUGH THE
MIDDLE OF THE WEEK WITH NIGHT AND MORNING COASTAL LOW CLOUDS
SPREADING LOCALLY INTO PORTIONS OF THE WESTERN VALLEYS AT TIMES.
THIS WILL BE FOLLOWED BY A COOLING TREND WITH HIGH TEMPERATURES
FOR NEXT WEEKEND AROUND AVERAGE.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
UPDATE: MOST OF THE LOW CLOUDS HAVE SCATTERED OUT COMPLETELY, WITH
ONLY A FEW AREAS OF BROKEN SKIES RIGHT ALONG THE IMMEDIATE COAST OF
SOUTHERN SAN DIEGO COUNTY. THERE LOOKS TO BE A RESURGENCE OF THE
MARINE LAYER AGAIN TONIGHT, ALTHOUGH CONFIDENCE IS LOW AS TO WHICH
AREAS WILL BECOME OVERCAST GIVEN WEAK OFFSHORE FLOW OVERNIGHT. THERE
COULD ALSO BE SOME PATCHY AREAS OF FOG FOR SOME OF THE COASTAL AREAS
AND AROUND 5 TO 10 MILES INLAND, ESPECIALLY FOR SAN DIEGO COUNTY.
THERE COULD ALSO BE SOME AREAS OF FOG DEVELOPING DURING THE EARLY
MORNING HOURS TOMORROW FOR PORTIONS OF THE WIND-SHELTERED VALLEYS.
THE INVERSION WILL CONTINUE TO LOWER OVER THE NEXT FEW DAYS AS THE
RIDGE BUILDS WITH INCREASED SUBSIDENCE, WHICH WILL ALSO HELP TO ALSO
HINDER THE MARINE LAYER DEVELOPMENT OVERNIGHT BY WEDNESDAY AND
THURSDAY. MODELS ARE STILL ON TRACK FOR A COOLDOWN TO MORE SEASONAL
TEMPERATURES BY THIS UPCOMING WEEKEND AS THE RIGHT BEGINS TO BREAK
DOWN AND TROUGHING UPSTREAM ADVANCES CLOSER TO THE REGION.
(PREVIOUS DISCUSSION SUBMITTED AT 250 AM):
SHORT TERM (TODAY THROUGH WEDNESDAY)
A WARMING TREND IS EXPECTED THROUGH WEDNESDAY FOR THE COAST AND
VALLEYS AND FOR THE DESERTS THROUGH THURSDAY. ENSEMBLE GUIDANCE
FOR WEDNESDAY AND THURSDAY WAS WARMEST FOR THE MODEL RUNS AROUND
FRIDAY OF LAST WEEK AND HAS SINCE COOLED A FEW DEGREES DEPENDING
ON LOCATION. WITH THE WARMING, HIGH TEMPERATURES WILL STILL BE
AROUND 10 DEGREES ABOVE AVERAGE ON WEDNESDAY WITH HIGH
TEMPERATURES RANGING FROM THE LOWER 70S NEAR THE COAST TO THE
LOWER TO MID 90S FOR THE INLAND EMPIRE WITH 102 TO 106 FOR THE
LOWER DESERTS.
THE MARINE LAYER IS STILL AROUND 4000 FEET DEEP, BUT WITH LIMITED
COVERAGE OF LOW CLOUDS FOR COASTAL LAND AREAS. THERE WILL BE WEAK
NORTHERLY LOWER LEVEL FLOW THIS MORNING WITH NORTHERLY WIND GUSTS
TO AROUND 30 MPH ALONG THE COASTAL SLOPES OF THE MOUNTAINS. THE
MARINE LAYER WILL DECREASE IN DEPTH TO AROUND 1500 TO 2000 FEET
FOR THE MIDDLE PART OF THE WEEK WITH NIGHT AND MORNING COASTAL
LOW CLOUDS SPREADING INTO PORTIONS OF THE WESTERN VALLEYS AT
TIMES.
LONG TERM (THURSDAY THROUGH SUNDAY)
ON THURSDAY, HIGH TEMPERATURES FOR THE DESERTS WILL CONTINUE TO
WARM ANOTHER FEW DEGREES WHILE THE COAST AND VALLEYS COOL A FEW
DEGREES. THAT COOLING WILL SPREAD INLAND THROUGH NEXT WEEKEND AS
HIGH PRESSURE ALOFT WEAKENS AND ONSHORE FLOW STRENGTHENS. WITH THE
COOLING, HIGH TEMPERATURES FOR NEXT WEEKEND WILL BE AROUND
AVERAGE. HIGH TEMPERATURES FOR NEXT SUNDAY WILL RANGE FROM THE MID
TO UPPER 60S NEAR THE COAST TO THE LOWER TO MID 80S FOR THE
INLAND EMPIRE WITH THE LOWER DESERTS AROUND 100.
AVIATION
191530Z...COAST...PATCHY LOW CLOUDS WILL CONTINUE TO SCATTER OUT
THIS MORNING, FULLY BY 17Z. LOW CLOUDS WITH BASES AROUND 600-900
FEET MSL WILL GRADUALLY INCREASE AFTER 06Z AND OVERNIGHT, BUT WITH
SOMEWHAT RANDOM COVERAGE AND LESS INLAND COVERAGE. MOST LIKELY
COVERAGE BETWEEN 10-16Z TUESDAY, AND SCATTER OUT BY 16Z.
INLAND...CLEAR WITH UNRESTRICTED VIS THROUGH TUESDAY MORNING.
MARINE
NO HAZARDOUS MARINE CONDITIONS EXPECTED THROUGH SATURDAY.
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...17
AVIATION/MARINE...MARTIN
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