260
FXUS66 KSGX 111805
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
1105 AM PDT SAT APR 11 2026
SYNOPSIS
LOW PRESSURE SYSTEMS WILL IMPACT THE REGION THROUGH MONDAY. THESE
ARE GOING TO BE ACCOMPANIED BY COOLER, WETTER. AMD WINDIER
WEATHER. A CHANCE FOR LIGHT SHOWERS WILL OCCUR TONIGHT INTO
SATURDAY MORNING. THESE WEATHER SYSTEMS WILL ALSO BRING THE CHANCE
OF LIGHT TO MODERATE RAINFALL AND HIGH ELEVATION SNOW. THE
HEAVIEST RAINFALL AND MOUNTAIN SNOWFALL IS EXPECTED ON SUNDAY,
WHERE THERE IS A SLIGHT CHANCE OF THUNDERSTORMS WEST OF THE
MOUNTAINS. THIS LOW PRESSURE SYSTEM MAY LINGER OVER THE AREA INTO
MONDAY, BRINGING ADDITIONAL LIGHT SHOWERS. DRIER AND SLIGHTLY
WARMER WEATHER IS EXPECTED BY THE MIDDLE AND END OF NEXT WEEK.
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
TODAY THROUGH TOMORROW NIGHT...
ONSHORE FLOW OUT OF THE SOUTHWEST IS BECOMING ENHANCED BY TROUGHING
UPSTREAM WHICH IS ADVANCING TOWARDS THE REGION. THIS HAS ALLOWED FOR
THE MARINE LAYER TO BECOME MORE ELEVATED AND SOMEWHAT DISPERSED THIS
NIGHT, WITH BEST COVERAGE ALONG THE COASTAL-FACING SLOPES. AS THE
FIRST ASSOCIATED SHORTWAVE WITH THIS TROUGH PROPAGATES OVER SOCAL
TODAY, THERE IS A SLIGHT CHANCE OF A FEW SHOWERS DEVELOPING,
ESPECIALLY AGAINST THE FOOTHILLS AND COASTAL-FACING SLOPES. ANY
MEASURABLE PRECIP THAT FALLS WILL LIKELY BE GENERALLY LESS THAN A
TENTH OF AN INCH, AND POSSIBLY ONLY UP TO A QUARTER OF AN INCH
LOCALLY FOR SOME OF THE MOUNTAINS. HOWEVER, THE ONLY REAL NOTABLE
IMPACT FROM THIS TODAY WILL BE MUCH COOLER TEMPERATURES AND GUSTY
WINDS.
IT WILL BE THE SECONDARY LOW DEEPENING AND PUSHING THROUGH BY
LATER THIS EVENING INTO SUNDAY THAT WILL PROVIDE A BETTER CHANCE OF
SHOWERS. THERE WILL ALSO BE ENOUGH INSTABILITY WITH THE U/L LOW
FEATURE ASSOCIATED WITH THIS THAT IT MAY ALLOW FOR THERE TO BE A FEW
THUNDERSTORMS. BETTER PRECIPITATION AMOUNTS ARE EXPECTED TOMORROW,
WITH AMOUNTS OF GENERALLY A QUARTER TO A HALF AN INCH FOR THE
COASTAL TO INLAND AREAS, AND HIGHER TO AROUND THREE QUARTERS OF AN
INCH FOR THE COASTAL SLOPES AND FOOTHILLS. AMOUNTS WILL TYPICALLY BE
FROM A HALF TO AN INCH FOR THE MOUNTAINS, ALTHOUGH THE COASTAL-
FACING SLOPES OF THE SAN BERNARDINO MOUNTAINS MAY RECEIVE LOCALLY
HIGHER AMOUNTS UP TO 1.5 INCHES. FOR ELEVATIONS ABOVE 5000 FT, THERE
MAY ALSO BE SNOW ACCUMULATIONS RANGING FROM A DUSTING, UP TO 2
INCHES AROUND THE VICINITY OF BIG BEAR LAKE. WINDS WILL ALSO BE
RATHER STRONG AND GUSTY, ESPECIALLY ACROSS THE HIGHER TERRAIN AND
WITHIN THE WIND-PRONED AREAS, ALTHOUGH STRONGEST GUSTS FOR THE MOST
IMPACTED AREAS WILL GENERALLY BE BETWEEN 45 TO 50 MPH, AND SHOULD
PRIMARILY BE BELOW WIND ADVISORY CRITERIA. A MOUNTAINTOP INVERSION,
COUPLED WITH A WEAK MOUNTAIN WAVE SETUP, WILL HELP TO ENHANCE
WINDS SLIGHTLY MORE DURING THE EARLY MORNING HOURS ON SUNDAY, AND
WINDS MAY PEAK OVER CRITERIA ON THE LEEWARD SIDE WITHIN THE LOWER
DESERTS FOR A FEW HOURS DURING THIS TIMEFRAME UNTIL THE WINDS
BETTER MIX BY LATER IN THE MORNING. AGAIN, THIS WILL LIKELY BE
SHORT-LIVED, BUT MAY PRODUCE SOME BLOWING DUST AS A RESULT ACROSS
SOME OF THE LOWER DESERT LOCATIONS DOWNWIND OF THESE STRONGER GAP
FLOW WINDS THROUGH THE PASSES. SUNDAY WILL ALSO HAVE MUCH STRONGER
COLD AIR ADVECTION BEHIND THIS SYSTEM, WITH RAPIDLY DROPPING SNOW
LEVELS BY LATER IN THE EVENING, AND HIGHS BEING THE COLDEST OF
THE WEEK.
MONDAY THROUGH FRIDAY...
BY MONDAY, THE SECONDARY MAJOR SHORTWAVE TROUGH IS GOING TO CONTINUE
TO EXIT THE REGION, WITH LINGERING SHOWERS TAPERING OFF THROUGHOUT
THE DAY, MAINLY FOR THE COASTAL-FACING SLOPES. DRIER CONDITIONS WILL
RETURN BY LATER IN THE EVENING ON MONDAY AND GOING INTO TUESDAY AS
WEAK RIDGING ALOFT PROPAGATES OVERHEAD, WHICH WILL FOLLOW INTO
WEDNESDAY WITH DRIER CONDITIONS REMAINING IN PLACE THROUGH THEN.
TEMPERATURES WILL STILL BE QUITE CHILLY ON MONDAY, WITH SOME OF THE
MOUNTAIN LOCATIONS BEING AS MUCH AS 15 DEGREES BELOW AVERAGE, BUT
THEN REBOUND QUITE NICELY WITH NOTABLY WARMER HIGH TEMPS FOR TUESDAY
AND WEDNESDAY. DETERMINISTIC MODELS DO REFLECT GENERAL AGREEMENT
WITH ANOTHER TROUGH DEEPENING OVER THE GREAT BASIN REGION THURSDAY
INTO FRIDAY, WHICH WILL LIKELY JUST INFLUENCE US WITH MORE WINDS IN
SOCAL, ALTHOUGH THIS COULD ALLOW FOR THERE TO BE SOME SHOWERS WEST
OF THE MOUNTAINS, AS WELL AS A REINFORCEMENT OF COOLER TEMPERATURES
ON THURSDAY. THIS WILL TRANSLATE TO A PERSISTENCE OF THE MARINE
LAYER AND ONSHORE FLOW PREDOMINANTLY THROUGHOUT THE WORK WEEK, WITH
TEMPERATURES PRIMARILY BEING BELOW THE SEASONAL AVERAGE FOR THIS
TIME OF YEAR.
AVIATION
111800Z...COASTS/VALLEYS...PRECIPITATION FROM THIS MORNING HAS
CLEARED OUT, WITH FEW-SCT CUMULUS (BASED AROUND 2000-3000FT MSL)
DRAPED ACROSS THE COASTAL BASIN FOR THIS MORNING INTO THE AFTERNOON.
VFR PREVAILS THROUGH THIS EVENING WITH THE NEXT DISTURBANCE BRINGING
THE RETURN OF LARGELY BKN CLOUDS AROUND 3500FT MSL, SET TO FILL
BACK IN ACROSS THE COASTAL BASIN STARTING AFTER 02Z SUNDAY. VERY
SCATTERED -SHRA BECOME POSSIBLE AROUND 12Z, THOUGH A MORE DEFINED
BAND OF PRECIPITATION WILL MOVE FROM NW TO SE FROM 14-22Z SUNDAY
MORNING. THIS BAND OF RAINFALL WILL BRING MVFR CIGS NEAR 2000FT MSL,
WITH VIS 4-6SM IN -RA/BR. POCKETS OF HEAVIER RAINFALL COULD BRING
CIGS BELOW 1000FT WITH VIS CLOSER TO 2-4SM.
MOUNTAINS/DESERTS
WEST TO SOUTHWEST WINDS PICK UP AFTER 19Z
TODAY, WITH GUSTS 35-50 KT THROUGH PASSES, ALONG DESERTS SLOPES AND
LOCALLY INTO THE DESERTS. LOCAL AREAS BLDU (VIS 3-5SM) EXPECTED.
MODERATE UP/DOWNDRAFTS IN LEE OF MTNS. WINDS DECREASE BY ABOUT 10-15
KTS AFTER 06Z, BUT REMAINS ELEVATED INTO THE OVERNIGHT HOURS,
PICKING BACK UP BY 18-21Z SUNDAY.
MARINE
THERE IS A SLIGHT (~10%) CHANCE OF THUNDERSTORMS SUNDAY AFTERNOON.
ADDITIONALLY THERE WILL BE PERIODS OF INCREASED NORTHWEST WINDS WITH
GUSTS 15 TO 20 KT AND CHOPPY SEAS THROUGH THE DAY SUNDAY.
SGX WATCHES/WARNINGS/ADVISORIES
CA...NONE.
PZ...NONE.
PUBLIC...STEWEY
AVIATION/MARINE...MUNYAN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page