730
FXUS66 KSGX 101951
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1251 PM PDT MON AUG 10 2026
SYNOPSIS
MINOR TO MODERATE HEATRISK TODAY WITH COOLER WEATHER TUESDAY AND
BEYOND, HIGH TEMPERATURES FALLING BELOW NORMAL BY WEDNESDAY.
MONSOON THUNDERSTORM CHANCES EACH DAY IN THE MOUNTAINS THROUGH
WEDNESDAY, WITH BEST CHANCES AND HEAVIEST RAIN TODAY AND TUESDAY.
DEEPENING MARINE LAYER THROUGH THE END OF THE WEEK WITH BREEZY
WINDS IN THE MOUNTAINS AND DESERTS.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
..UPDATED AVIATION DISCUSSION
MID LEVEL WATER VAPOR SHOWS TROUGHING TO THE NORTHWEST WITH THE
RIDGE IN PLACE OVER THE FOUR CORNERS REGION, POISED TO WEAKEN INTO
TUESDAY AS THE TROUGH BECOMES MORE PRONOUNCED. MINOR TO MODERATE
HEATRISK CONTINUES TODAY FOR MUCH OF THE REGION, ALTHOUGH
TEMPERATURES BEGIN A COOLING TREND TODAY, REACHING NEAR NORMAL BY
TUESDAY AFTERNOON. HIGH CLOUDS WILL CONTINUE TO MOVE INTO THE REGION
TODAY AS SOUTHEASTERLY FLOW SHUNTS MOISTURE NORTHWARD, BUT THESE
CLOUDS SHOULDN'T MEANINGFULLY LIMIT STORM POTENTIAL IN THE MOUNTAINS
THIS AFTERNOON. THE MORNING SOUNDING INDICATED DECENT CAPE AND
INCREASING PWS OF 1.3-1.6", WITH MODELS SIGNALING A WIDE SWATH OF
INSTABILITY TO SET UP TODAY STRETCHING FROM SOUTHWESTERN ARIZONA
INTO SOUTHEASTERN CALIFORNIA. THIS INSTABILITY, ALONG WITH THE AMPLE
MOISTURE IN THE MID AND LOWER LEVELS, WILL BE KEY FOR MORE
WIDESPREAD MONSOONAL THUNDERSTORMS TODAY, LIKELY KICKING OFF AS
EARLY AS NOON. WHILE MUCH OF THE CONVECTION TODAY WILL BE
ANCHORED TO THE MOUNTAINS, A FEW STORMS MAY MIGRATE INTO THE
DESERTS AND/OR FAR EASTERN VALLEYS WITH BRIEF, HEAVY RAINFALL.
RAIN RATES IN THE HIGHER TERRAIN WILL BE A BIT MORE IMPRESSIVE
TODAY, WITH 1"/HR OR HIGHER NOT OUT OF THE QUESTION FOR THE SAN
DIEGO AND RIVERSIDE COUNTY MOUNTAINS. FURTHER NORTH IN SAN
BERNARDINO, THERE WILL BE A SIGNIFICANT CUT OFF OF THE MOISTURE
NEAR THE BORDER WITH LA COUNTY. THEREFORE, LESSER MAX RAIN RATES
CLOSER TO 0.5-0.75"/HR CAN BE EXPECTED, WITH THE STRONGEST STORMS
LIKELY ON THE EASTERN/NORTHEASTERN SLOPES OF THE SB COUNTY
MOUNTAINS. WHILE WIDESPREAD FLOODING ISN'T EXPECTED, SOME
LOCALIZED SPOTS, ESPECIALLY NEAR THE PEAKS OR EASTERN SIDES OF THE
MOUNTAINS, COULD SEE SOME BRIEF FLOODING BOTH TODAY AND TOMORROW.
AS ALWAYS WITH ANY THUNDERSTORM, FREQUENT LIGHTNING, GUSTY WINDS,
AND SMALL HAIL WILL BE POSSIBLE. ENSURE YOU ARE PREPARED TO TAKE
SHELTER IN A STURDY AND ENCLOSED STRUCTURE SHOULD YOU HEAR
THUNDER.
THE RIDGE CONTINUES TO WEAKEN ON TUESDAY WITH SOME MODELS NOW
INDICATING A WEAK EASTERLY WAVE MAY MOVE ACROSS TUESDAY MORNING,
WHICH COULD ALLOW FOR SOME MORNING RAINFALL FOR THE DESERTS AND FAR
INLAND AREAS. SHOULD THIS COME TO PASS, A RUMBLE OF THUNDER OR TWO
CANNOT BE RULED OUT. THIS WILL BE SOMETHING TO CLOSELY WATCH AS ANY
MORNING CONVECTION COULD LIMIT AFTERNOON STORMS IN THE MOUNTAINS. AS
IT STANDS NOW, ADDITIONAL MOISTURE WILL BE PUSHED INTO THE REGION ON
TUESDAY WITH A SLIGHT DECREASE IN THE INSTABILITY, ALLOWING FOR
ANOTHER ROUND OF MONSOONAL THUNDERSTORMS TUESDAY AFTERNOON.
CONDITIONS LOOK CONDUCIVE FOR A RINCE-AND-REPEAT OF MONDAY, BUT WITH
THE POTENTIAL FOR SLIGHTLY HIGHER RAIN RATES/LOCALIZED FLOODING AS
PWS PEAK ABOVE 1.5". AGAIN, MUCH OF THIS WILL DEPEND ON WHAT OCCURS
TUESDAY MORNING WITH ANY EASTERLY WAVE, BUT FOR NOW, WILL CONTINUE
TO MESSAGE WIDESPREAD MOUNTAIN THUNDERSTORMS FOR TUESDAY AFTERNOON.
AFTER TUESDAY, THE AFOREMENTIONED UPPER LEVEL TROUGH WILL ENCOMPASS
MUCH OF CALIFORNIA AS THE STATE EXPERIENCES A SIGNIFICANT COOLDOWN,
WITH TEMPERATURES FALLING TO 3-10 DEGREES BELOW NORMAL WED-FRI AND
THE MARINE LAYER DEEPENS EACH DAY. THIS WILL BE THE FIRST TIME IN
NEARLY A MONTH THAT HIGHS WILL BE BELOW NORMAL, SO TAKE ADVANTAGE OF
THE COOLER WEATHER! MONSOONAL MOISTURE WILL LINGER IN THE REGION
WHICH COULD ALLOW FOR SOME ABNORMALLY WARMER MORNINGS, BUT WITH
LIMITED FORCING, AFTERNOON THUNDERSTORM CHANCES WILL BE FALLING
THROUGH THE END OF THE WEEK. STILL, MODELS CONTINUE TO PUSH FOR A
FEW STORMS OVER THE SAN BERNARDINOS WEDNESDAY AFTERNOON AS THE
TROUGH BEGINS TO MOVE IN. OTHERWISE, QUIETER WEATHER FOR THE END OF
THE WEEK AND WEEKEND WITH COOLER WEATHER/A MORE ROBUST MARINE LAYER
AND AFTERNOON BREEZY WINDS IN THE DESERTS AND MOUNTAIN PASSES.
AVIATION
101945Z....COAST...VFR CONDITIONS EXPECTED THIS AFTERNOON AND
EVENING. PATCHY LOW CLOUDS TO GRADUALLY DEVELOP OVERNIGHT,
INCREASING IN COVERAGE AND DURATION, WITH BEST CHANCES OF CIGS
BETWEEN 11-15Z TUESDAY. BASES AROUND 700-1000 FEET MSL. SCATTER OUT
OF ANY CIGS TUESDAY BY 17Z.
VALLEYS/MOUNTAINS/DESERTS...SCT-BKN CLOUDS MOSTLY ABOVE 15000 FEET
THROUGH 18Z TUE. SCATTERED TSRA OVER MTNS WITH AN ISOLD TSRA OR TWO
IN THE HIGH DESERT TO 02Z TUE WITH BASES AROUND 9000 FEET MSL WITH
TOPS TO 50000 FEET. ANY TSRA COULD PRODUCE LIGHTNING, STRONG
UP/DOWNDRAFTS AND ASSOCIATED VIS REDUCTIONS.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH SATURDAY.
BEACHES
HIGH TIDES WILL EXCEED 7 FEET DURING EVENINGS TODAY THROUGH
WEDNESDAY BETWEEN 800-930 PM, RESULTING IN MINOR TIDAL OVERFLOW OF
LOW-LYING AREAS ALONG THE BEACH. SURF WILL BE LOW AND IS NOT
EXPECTED TO ADD MUCH TO THE FLOODING POTENTIAL. CHECK THE COASTAL
FLOOD ADVISORY FOR DETAILS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...COASTAL FLOOD ADVISORY FROM 6 PM THIS EVENING TO 11 PM PDT
WEDNESDAY FOR ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY
COASTAL AREAS.
PZ...NONE.
PUBLIC...ZUBER
AVIATION/MARINE/BEACHES...SMALL
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