403
FXUS66 KSGX 071846
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1146 AM PDT FRI AUG 7 2026
SYNOPSIS
THROUGH SUNDAY MODERATE HEATRISK EXPECTED FOR THE INLAND VALLEYS AND
MOUNTAINS WITH MAJOR HEATRISK IN THE DESERTS. THERE ARE CHANCES OF
SHOWERS AND THUNDERSTORMS IN THE MOUNTAINS EACH AFTERNOON THROUGH
TUESDAY. THERE ARE LOWER CHANCES TODAY AND SATURDAY WITH INCREASED
THUNDERSTORM CHANCES EARLY NEXT WEEK. COASTAL AREAS WILL CONTINUE TO
SEE LOW CLOUDS EACH NIGHT AND MORNING THROUGH THE FORECAST PERIOD.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
AN ISOLATED CONVECTIVE CELL DEVELOPED AROUND 8 AM ALONG THE SAN
DIEGO COAST STARTING IN LA JOLLA AND EVENTUALLY MOVING OFFSHORE NEAR
ENCINITAS. A FEW LIGHTNING STRIKES OCCURRED NEAR SOLANA
BEACH/ENCINITAS. RAINFALL TOTALS OUT OF THAT CELL RANGED FROM 0.03
INCHES OF RAIN TO 0.36 INCHES BETWEEN LA JOLLA AND ENCINITAS. FOR
THE REST OF THE DAY, DRY CONDITIONS ARE EXPECTED WEST OF THE
MOUNTAINS BUT THERE REMAINS SLIGHT CHANCES OF SHOWERS AND ISOLATED
THUNDERSTORMS IN THE MOUNTAINS AND HIGH DESERT. LATEST HIGH
RESOLUTION GUIDANCE IS INDICATING SHOWERS THAT DEVELOP TODAY AND
SATURDAY WILL SEE RAINFALL RATES 0.10 INCH PER HOUR OR LESS, WITH
ONLY A 10 PERCENT CHANCE OF RAINFALL RATES EXCEEDING THAT.
THROUGH SUNDAY HIGH TEMPERATURES ARE EXPECTED TO RUN 5 TO 10 DEGREES
ABOVE AVERAGE FOR INLAND AREAS. LOW TEMPERATURES WILL ALSO RUN ABOVE
AVERAGE, MOST NOTICEABLE IN THE MOUNTAINS AND DESERTS WHERE LOWS
WILL BE 10 TO 15 DEGREES ABOVE AVERAGE. FOR THE INLAND VALLEYS AND
MOUNTAINS MODERATE HEATRISK IS EXPECTED WHICH MEANS THAT FOLKS WHO
ARE SENSITIVE HEAT, ESPECIALLY THOSE WITHOUT CONSISTENT
COOLING/HYDRATION WILL BE MOST IMPACTED. IN THE DESERTS, MAJOR
HEATRISK INDICATES ANYONE MAY SEE NEGATIVE IMPACTS FROM THE HEAT IF
PRECAUTIONS AREN'T TAKEN. MAKE SURE TO STAY HYDRATED AND IF POSSIBLE
AVOID STRENUOUS ACTIVITY DURING THE HOTTEST PARTS OF THE DAY (10 AM
TO 4 PM). HIGH TEMPERATURES ARE EXPECTED TO GRADUALLY DECREASE NEXT
WEEK, BRINGING TEMPERATURES BACK DOWN TO NEAR OR SLIGHTLY BELOW
AVERAGE BY THE MIDDLE OF NEXT WEEK.
SUNDAY THROUGH TUESDAY, THE RIDGE OF HIGH PRESSURE WILL SHIFT EAST
MORE OVER THE FOUR CORNERS REGION. THIS WILL ALLOW FOR ADDITIONAL
INFLUXES OF MOISTURE INTO THE AREA AND INCREASE OUR CHANCES FOR
SHOWERS AND THUNDERSTORMS. LATEST GUIDANCE DOESN'T SHOW A FORCING
MECHANISM OUTSIDE OF THE USUAL DAYTIME HEATING FROM THE SUN BUT THAT
COULD CHANGE AS WE GET CLOSER. THE CURRENT FORECAST KEEPS
THUNDERSTORM CHANCES CONFINED TO THE MOUNTAINS, LOCALLY INTO THE
HIGH DESERT, IN THE AFTERNOONS EACH DAY SUNDAY THROUGH TUESDAY. FOR
SUNDAY, THE LATEST REFS 90TH PERCENTILE HOURLY RAINFALL RATE PEAKS
AT 0.55 INCHES PER HOUR, WITH ONLY 10 PERCENT CHANCE OF EXCEEDING
THAT.
AVIATION
071830Z....COASTS...LOW CLOUDS HAVE BURNED OFF WITH FEW-SCT HIGH CU
AOA 15,000FT MSL MOVING NORTHWARD. PATCHY LOW CLOUDS DEVELOP AGAIN
TONIGHT AFTER 02Z SAT AND MOVE INLAND, WITH BASES AROUND 1000FT MSL.
CLEARING SHOULD OCCUR BACK TOWARDS THE COAST BY 16-17Z SAT.
VALLEYS/MOUNTAINS/DESERTS
VFR WITH FEW-SCT CLOUDS AOA 20,000FT
MSL THROUGH SATURDAY. LOW CHANCE (10%) FOR TSRA OVER THE MOUNTAINS
THIS AFTERNOON BETWEEN 20Z-02Z.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH TUESDAY.
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 SUNDAY FOR RIVERSIDE COUNTY
MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS-SAN BERNARDINO
AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO
COUNTY MOUNTAINS.
HEAT ADVISORY FROM 10 AM SATURDAY TO 8 PM PDT SUNDAY FOR ORANGE
COUNTY INLAND AREAS-SAN DIEGO COUNTY VALLEYS-SANTA ANA
MOUNTAINS AND FOOTHILLS.
EXTREME HEAT WARNING UNTIL 8 PM PDT SUNDAY FOR APPLE AND LUCERNE
VALLEYS-COACHELLA VALLEY-SAN DIEGO COUNTY DESERTS-SAN
GORGONIO PASS NEAR BANNING.
PZ...NONE.
PUBLIC...CO
AVIATION/MARINE...ZUBER
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