Weather Service Report


820 
FXUS66 KSGX 311532
AFDSGX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
900 AM PDT FRI OCT 31 2014

.SYNOPSIS...
A TROUGH OF LOW PRESSURE DEEPENING ALONG THE WEST COAST TODAY WILL 
BRING COOLER WEATHER AND A RAPIDLY DEEPENING MARINE LAYER. RAIN AND 
HIGHER MOUNTAIN SNOW ARE LIKELY TONIGHT INTO SATURDAY MORNING WITH A 
FEW SHOWERS POSSIBLE THROUGH SUNDAY MORNING. WARMER DAYS 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...

THE MARINE LAYER HAS DEEPENED CONSIDERABLY WITH SOME CLOUDS REACHING 
UP MOUNTAIN SLOPES TO 5000 FEET AND NEARLY ALL OF THE COASTAL BASIN 
IS SHROUDED. SOME CLEARING IS EXPECTED TODAY...BUT NOT A WHOLE LOT. 
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 WILL CONTINUE TO DIG SOUTHWARD TONIGHT. SOCAL IS 
ON THE SOUTHERN EDGE OF THIS SYSTEM...BUT A LEGITIMATE COLD FRONT IS 
HEADED OUR WAY. MOISTURE BECOMES DEEP ENOUGH AND ENERGY SUFFICIENT 
FOR A BROAD BAND OF PRECIPITATION MOVING THROUGH OUR REGION 
HAPPENING MOSTLY BETWEEN MIDNIGHT AND 10 AM TONIGHT AND SATURDAY 
MORNING. 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 MOST SHOWERS. 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. LINGERING 
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. ALL 
MOUNTAINS AND DESERTS SHOULD PREPARE FOR SOME STRONG WINDS SATURDAY 
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 BELOW AVERAGE...WITH HIGHS MOSTLY IN THE 60S AT 
LOWER ELEVATIONS. ON MONDAY AND TUESDAY THE SECOND WAVE MOVES OFF 
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. ON WEDNESDAY THERE COULD BE SOME 
DECENT OFFSHORE WINDS IN THE USUAL SPOTS. TEMPS WILL HEAD INTO THE 
80S EVEN NEAR THE COAST BY WEDNESDAY. 

&&

.AVIATION...
311530Z...MULTIPLE BKN CLOUD LAYERS WITH BASES 2000-4000 FT MSL WEST 
OF THE MOUNTAINS THROUGH THE MORNING. CLOUDS BECOMING SCT-BKN WITH 
BASES 3000-4000 FT MSL AFTER 16-18Z. BASES LOWERING BACK TO AROUND 
2000 FT MSL AFTER 01/00Z. A COLD FRONT WILL BRING SCATTERED LIGHT 
SHOWERS ALONG AND WEST OF THE MTNS BEGINNING AROUND 
01/01-03Z...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.

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 5SM OR LESS IN BLDU/HZ.

&&

.MARINE...
830 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED TODAY. A COLD FRONT 
MOVING OVER THE COASTAL WATERS WILL BRING WEST TO NORTHWEST WINDS 
GUSTING TO 25-30 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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