616
FXUS66 KSGX 121040
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
240 AM PST THU FEB 12 2026
SYNOPSIS
SLIGHTLY WARMER AND DRIER WEATHER IS EXPECTED TOMORROW THROUGH
SATURDAY, WITH A FEW SHOWERS POSSIBLE OVER THE MOUNTAINS TOMORROW
AFTERNOON. A MORE ROBUST WEATHER SYSTEM WILL ENTER THE AREA SUNDAY
THROUGH THE EARLY PART OF NEXT WEEK. THIS WILL BRING MORE
WIDESPREAD RAINFALL, MOUNTAIN SNOW, AND WINDIER CONDITIONS. COOLER
TEMPERATURES WILL PREVAIL FOR MUCH OF NEXT WEEK.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
AREAS OF LOW CLOUDS CONTINUE OVER PARTS OF THE INLAND VALLEYS THIS
MORNING WITH BANDS OF HIGH CLOUDS MOVING NORTHEAST ACROSS THE
REGION. MORNING WATER VAPOR IMAGERY SHOWS A NEARLY STATIONARY
UPPER LOW OVER CENTRAL CALIFORNIA AND ANOTHER LOW IN THE BASE OF
THE LONG WAVE TROUGH AROUND 850 MI SOUTHWEST OF SAN DIEGO. THE LOW
IN THE BASE OF THE TROUGH WILL CONTINUE TO DIG SOUTH TODAY BEFORE
PROGRESSING EASTWARD ON FRIDAY. AT THE SAME TIME, THE NORTHERN LOW
WITHIN THE TROUGH WILL DROP SOUTH INTO SO CAL ON FRIDAY. FOR
TODAY, THIS WILL MAINTAIN COOL BUT DRY WEATHER WITH HIGHS NEAR
SEASONAL NORMALS. AS THE TROUGH AXIS MOVES ACROSS LATE TONIGHT
INTO FRIDAY MORNING, THERE IS A SLIGHT (15-20%) CHANCE OF
SHOWERS, MAINLY OVER THE RIVERSIDE AND SAN DIEGO COUNTY MOUNTAINS
AND ADJACENT DESERT SLOPES. WEAK OFFSHORE FLOW BRIEFLY DEVELOPS
BEHIND THE TROUGH, PROVIDING A LITTLE WARMING. TRANSITORY UPPER
LEVEL RIDGING FOLLOWS FOR SATURDAY WITH HIGHS INCREASING TO AROUND
2 TO 7 DEGREES ABOVE NORMAL.
A LARGE UPPER LEVEL LOW DROPS OUT OF THE GULF OF ALASKA AND
TOWARDS THE NORTHERN CA COAST THIS WEEKEND. THE INITIAL TROUGH IS
FORECAST TO MOVE INLAND ACROSS CA LATE SUNDAY THROUGH TUESDAY
MORNING. ENSEMBLES ARE SHOWING A WEAK ATMOSPHERIC RIVER WITH THIS
TROUGH SOMETIME MONDAY OR MONDAY NIGHT WHEN THERE IS 80-90%
CHANCE OF IVT OF 250 KG/M/S OR MORE, THOUGH THERE ARE STILL TIMING
DIFFERENCES ON WHEN THIS WILL OCCUR. UNLIKE PREVIOUS AR EVENTS
THIS WINTER, THIS STORM WILL BE MUCH COLDER WITH SNOW LEVELS
SOMEWHERE BETWEEN 5500 AND 6500 FT DURING THE HEAVIEST
PRECIPITATION. IN TERMS OF RAINFALL AMOUNTS FOR THE 48 HOUR PERIOD
FROM 4 AM MONDAY THROUGH 4 AM WEDNESDAY, THE NBM HAS A 75-95%
CHANCE OF 0.50" OR MORE FOR THE MOUNTAINS WESTWARD, A 30-50%
CHANCE OVER THE HIGH DESERTS, AND A 15-30% CHANCE OVER THE LOW
DESERTS. CHANCES OF 1" OR MORE ARE AROUND 40-65% FOR THE MOUNTAINS
WESTWARD, LOCALLY UP TO 95% ON THE SOUTH SLOPES OF THE SAN
BERNARDINO MOUNTAINS, AND A 5-10% CHANCE IN THE DESERTS. FOR THIS
SAME 48 HR PERIOD, THERE IS AROUND AN 80% CHANCE OF 6" OR MORE OF
SNOW ABOVE 6000 FT, AND AROUND A 40-50% CHANCE DOWN TO 5000 FT.
CHANCES OF 12" OR MORE ARE AROUND 60% ABOVE 6000 FT AND 25% DOWN
TO 5000 FT. THIS PERIOD WILL BE MUCH COOLER WITH HIGHS AROUND
5-10 DEGREES BELOW NORMAL. GUSTY SOUTHWEST TO WEST WINDS ARE ALSO
EXPECTED ACROSS THE COASTAL WATERS, MOUNTAINS, AND DESERTS WITH
THIS SYSTEM.
ADDITIONAL TROUGHS WILL MOVE THROUGH INTO AT LEAST THURSDAY,
THOUGH AS TIME GOES ON THE ENSEMBLES BECOME SLIGHTLY OUT OF PHASE,
LEADING TO LOWER CONFIDENCE ON WHEN ADDITIONAL ROUNDS OF
PRECIPITATION WILL OCCUR. IN GENERAL, THESE SUBSEQUENT TROUGHS ARE
CURRENTLY FORECAST TO HAVE LESS MOISTURE AND LOWER PRECIPITATION
ACCUMULATION ASSOCIATED WITH THEM COMPARED TO THE EARLY WEEK
SYSTEM. THE PROBABILITY OF PRECIPITATION FLUCTUATES BETWEEN 20-45%
FOR WEDNESDAY AND THURSDAY, HIGHEST WEDNESDAY MORNING AND LATE
THURSDAY. THESE SYSTEMS ARE ALSO COLDER, WITH A 15-35% CHANCE OF
SNOW LEVELS OF 4000 FT OR LOWER, WITH THE HIGHEST PROBABILITIES
ACROSS THE SAN BERNARDINO MOUNTAINS. IT IS NOT OUT OF THE QUESTION
THAT RESORT LEVELS COULD SEE CLOSE TO 2 FEET OF TOTAL SNOW
ACCUMULATION BY THE END OF THE WEEK.
AVIATION
121030Z...AREAS OF LOW CLOUDS BASED AROUND 2500-4000 FEET MSL
WILL CONTINUE OVER THE COASTAL BASIN, MOST LIKELY OVER VALLEYS
INTO FOOTHILLS THIS MORNING. TERRAIN PARTIALLY OBSCURED BETWEEN
THOSE ELEVATIONS. SCATTER OUT EXPECTED 15-17Z. PATCHY COASTAL LOW
CLOUDS BASED AROUND 1500-2000 FEET MSL TO RETURN AFTER 06Z TONIGHT
INTO FRIDAY. OTHERWISE, VARIABLE HIGH CLOUDS ABOVE 15000 FEET MSL
TODAY AND TONIGHT.
MARINE
NO HAZARDOUS MARINE CONDITIONS ARE EXPECTED THROUGH SUNDAY. A STORM
SYSTEM WILL APPROACH SUNDAY NIGHT. SOUTH WINDS WILL INCREASE SUNDAY
NIGHT AND MONDAY, LIKELY GENERATING HAZARDOUS WINDS AND SEAS.
SKYWARN
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
SGX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.
PUBLIC...SS
AVIATION/MARINE...MM
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