Area Forecast Discussion
Issued by NWS San Diego, CA

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000
FXUS66 KSGX 312040
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
200 PM PDT FRI OCT 31 2014

.SYNOPSIS...
A STORM SYSTEM WILL ARRIVE TONIGHT IN SOUTHERN CALIFORNIA AND SPREAD
RAIN...MOUNTAIN SNOW...AND BRISK WINDS ACROSS THE REGION THROUGH
SATURDAY MORNING. A FEW SHOWERS WILL LINGER THROUGH EARLY SUNDAY.
DRY AND WARM DAYS WILL RETURN NEXT WEEK AS HIGH PRESSURE AND
OFFSHORE FLOW DEVELOP.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

A DEEP MARINE LAYER WILL KEEP SKIES MOSTLY CLOUDY IN THE COASTAL
BASIN THROUGH THE EVENING. A LOW PRESSURE TROUGH...OUR FIRST OF THE
SEASON...IS DEEPENING OFF THE WEST COAST TODAY AND IS ALREADY
SPREADING SOME RAIN THROUGH NOCAL. THIS SYSTEM CONTAINS A POTENT
COLD FRONT AND DECENT MOISTURE SUFFICIENT FOR A BROAD BAND OF
PRECIPITATION THAT WILL MOVE THROUGH OUR REGION BETWEEN AFTER
MIDNIGHT TONIGHT THROUGH ABOUT 9 AM SATURDAY. THERE MAY BE SOME
LIGHT SHOWERS BEFORE MIDNIGHT THAT COULD MAKE SOME STREETS WET FOR
HOLIDAY PARTIES...BUT TRICK OR TREATERS FINISHING EARLY ENOUGH
SHOULD AVOID ANY SPOOKY WEATHER. SNOW WILL FALL IN THE HIGHER
ELEVATIONS AND LEVELS WILL DROP TO ABOUT 6000 FEET AFTER THE PASSAGE
OF THE COLD FRONT EARLY SATURDAY. SEVERAL INCHES ARE POSSIBLE ABOVE
7000 FEET...BUT LESS THAN 3 INCHES BELOW. A FEW SHOWERS ARE POSSIBLE
THROUGH SATURDAY MAINLY FOR THE MOUNTAINS AND FAR SOUTHERN SAN DIEGO
COUNTY. WINDS WILL START OUT GUSTY THROUGH MOUNTAIN RIDGES AND
PASSES TONIGHT...BUT BECOME QUITE STRONG AND MORE WIDESPREAD AS THE
COLD FRONT ARRIVES EARLY SATURDAY. THE STRONGEST WINDS WILL BE
SATURDAY MORNING BEFORE DECREASING LATE AFTERNOON. THE LOW PRESSURE
TROUGH HAS A SECOND WAVE; IT IS MUCH WEAKER BUT ROTATES THROUGH OUR
REGION EARLY SUNDAY MORNING. THIS COULD COAX A FEW MORE SHOWERS TO
DEVELOP SATURDAY NIGHT AND SUNDAY MORNING MAINLY IN MOUNTAINS AND
SOUTHERN SAN DIEGO COUNTY...SOME A RESULT OF ISLAND BANDS. TEMPS
OVER THE WEEKEND WILL BE WELL BELOW AVERAGE...WITH HIGHS MOSTLY IN
THE 60S AT LOWER ELEVATIONS. ON MONDAY AND TUESDAY THE TROUGH FINALL
MOVES ASIDE AND A HIGH PRESSURE RIDGE NOSES INTO THE WEST COAST.
MODELS DIFFER ON HOW STRONG OF A RIDGE IT WILL BE...BUT FAIR...DRY
AND MUCH WARMER WEATHER IS COMING. SOME OFFSHORE FLOW SETS UP AT THE
SAME TIME TO ADD TO THE WARMING/DRYING TREND. THERE COULD BE SOME
DECENT OFFSHORE WINDS IN THE USUAL SPOTS. TEMPS WILL HEAD INTO THE
80S EVEN NEAR THE COAST BY WEDNESDAY.

&&

.AVIATION...
312000Z...MULTIPLE SCT-BKN CLOUD LAYERS WITH BASES 3000-4000 FT MSL
THROUGH THE AFTERNOON. BASES LOWERING BACK TO AROUND 2000 FT MSL
AFTER 01/02Z. A COLD FRONT WILL BRING SCATTERED LIGHT SHOWERS ALONG
AND WEST OF THE MTNS BEGINNING AROUND 01/04-07Z...BECOMING HEAVIER
AND MORE WIDESPREAD AFTER MIDNIGHT WITH LOWERING CIGS. LIGHT SHOWERS
POSSIBLE OVER THE HIGH DESERTS AFTER 01/10Z...WITH LITTLE IF ANY
PRECIP IN THE LOW DESERTS. LOCAL MVFR/IFR CIGS AND VIS POSSIBLE IN
HEAVIER SHOWERS. COASTAL SLOPES OF THE MTNS WILL BE OBSCURED IN
CLOUDS AND PRECIPITATION THROUGH SAT MORNING. SHOWERS ENDING AND
CIGS LIFTING BY LATE SATURDAY MORNING...THOUGH BROKEN CIGS AROUND
5000 FT MSL WILL CONTINUE THROUGH THE AFTERNOON.

SW TO W WINDS 20-30 KT GUSTING TO 40-50 KT OVER MOUNTAIN RIDGES AND
ALONG DESERT SLOPES/ADJACENT DESERT FOOTHILLS WILL CREATE MOD-STG
UDDFS...LLWS AND ROTORS E AND NE OF THE MOUNTAINS AFTER 21Z. VIS
LOCALLY REDUCED TO 5 SM OR LESS IN BLDU/HZ.

&&

.MARINE...
100 PM...NO HAZARDOUS MARINE WEATHER IS EXPECTED TODAY. A COLD FRONT
MOVING OVER THE COASTAL WATERS WILL BRING WEST TO NORTHWEST WINDS
GUSTING TO 25 KT AND STEEP WAVES SATURDAY. A SMALL CRAFT ADVISORY
WILL BE IN EFFECT FROM EARLY SATURDAY MORNING THROUGH LATE SATURDAY
NIGHT...SEE LAXMWWSGX FOR DETAILS. CONDITIONS WILL IMPROVE DURING
THE DAY SUNDAY.

&&

.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED FOR TODAY. SKYWARN MAY BE
REQUESTED FOR LATE TONIGHT AND SATURDAY MORNING...PRIMARILY FOR
URBANIZED AND BURN SCAR FLOODING CONCERNS AND SNOW IN THE HIGHER
ELEVATIONS. WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT
WEATHER CONDITIONS.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...WIND ADVISORY FROM 8 PM THIS EVENING TO 5 PM PDT SATURDAY FOR
     THE APPLE AND LUCERNE VALLEYS...COACHELLA VALLEY...
     RIVERSIDE COUNTY MOUNTAINS...SAN BERNARDINO COUNTY
     MOUNTAINS...SAN DIEGO COUNTY DESERTS...SAN DIEGO COUNTY
     MOUNTAINS.

     WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 2 PM PDT
     SATURDAY ABOVE 6500 FEET FOR THE RIVERSIDE COUNTY
     MOUNTAINS...SAN BERNARDINO COUNTY MOUNTAINS.

     FLASH FLOOD WATCH FROM THIS EVENING THROUGH SATURDAY MORNING FOR
     THE SANTA ANA MOUNTAINS AND FOOTHILLS.

PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 5 AM PDT SATURDAY TO 4 AM
     PST SUNDAY FOR THE COASTAL WATERS FROM SAN MATEO POINT TO
     THE MEXICAN BORDER AND OUT 30 NM...WATERS FROM SAN MATEO
     POINT TO THE MEXICAN BORDER EXTENDING 30 TO 60 NM OUT
     INCLUDING SAN CLEMENTE ISLAND.


&&

$$

PUBLIC...THOR
AVIATION/MARINE...LOKI





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