FXUS66 KSGX 100506
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
905 PM PST WED DEC 9 2009
.SYNOPSIS...CLOUDS WILL GRADUALLY INCREASE THROUGH THURSDAY AHEAD OF
THE NEXT WEATHER SYSTEM. PATCHY FROST WILL OCCUR LATE TONIGHT IN
SOME OF THE INLAND VALLEYS...INCLUDING THE COACHELLA VALLEY. THE
NEXT SYSTEM IS EXPECTED TO BRING RAIN THURSDAY NIGHT AND
FRIDAY...WITH SOME SNOW IN MAINLY THE SAN BERNARDINO COUNTY
MOUNTAINS. A STRONGER STORM SYSTEM WILL MOVE THROUGH CALIFORNIA OVER
THE WEEKEND AND SHOULD BRING MORE SIGNIFICANT PRECIPITATION AND
STRONGER WINDS TO SOUTHERN CALIFORNIA. FAIR WEATHER WILL RETURN
AROUND MONDAY OF NEXT WEEK.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
A FEW HIGH CLOUDS WERE DRIFTING OVER...OTHERWISE SKIES WERE MOSTLY
CLEAR. HIGH CLOUDS WILL GRADUALLY INCREASE OVERNIGHT FROM THE
WEST...BUT OVERALL SKIES WILL BE MORE CLEAR THAN LAST NIGHT...SO IN
THE VALLEYS...MIN TEMPS SHOULD BE SLIGHTLY LOWER DESPITE WARMING AT
850 MB. MID/HIGH CLOUDS WILL GRADUALLY INCREASE THU...AND TEMPS
SHOULD BE VERY SLIGHTLY WARMER THAN TODAY.
STRONG BROAD UPPER LEVEL LOW PRESSURE CONTINUES OVER THE MID NORTH
PACIFIC...AND A FAST-MOVING SHORT WAVE WILL APPROACH SOUTHERN
CALIFORNIA. THE WAVE ITSELF WILL NOT BE VERY STRONG...BUT WE WILL BE
IN THE FRONT-LEFT QUADRANT OF A 110+ KNOT JET...FAVORABLE FOR
PRECIP. WITH MOISTURE UP TO AT LEAST 700 MB AND MODERATE WEST
FLOW...WE SHOULD AVERAGE AROUND 1/2 INCH...WITH LOCAL AMOUNTS OVER
AN INCH ON WEST SLOPES OF THE MTNS. TIMING OF THE PRECIP LOOKS BEST
BETWEEN ABOUT 06Z AND 18Z FRI...BUT AFTER THAT THE ATMOSPHERE STAYS
RATHER MOIST...SO SOME SHOWERS COULD LINGER FRI NIGHT. NOT TOO MUCH
SNOW SHOULD FALL IN THE MTNS AS THE SNOW LEVEL WILL GENERALLY BE
ABOVE 6000 FEET...AND THE WEST FLOW WILL NOT BE IDEAL FOR
OROGRAPHICS IN THE SAN BERNARDINO MTNS. STILL...WE COULD HAVE
AMOUNTS IN THE 2-5 INCH RANGE AT RESORT LEVELS.
A MORE SUBSTANTIAL SYSTEM IS EXPECTED OVER CALIFORNIA OVER THE
WEEKEND AS THE NEXT WAVE WILL BE BROADER...THOUGH IT WILL HIT AREAS
FURTHER NORTH STRONGER THAN HERE. TIMING IS A BIT UNCERTAIN WITH
PRECIP POSSIBLE ANYTIME BETWEEN SAT AND SUN. OROGRAPHICS COULD BE
QUITE STRONG WITH 35+ KNOT SW AT 850 MB...SO SW-FACING
MTNS...ESPECIALLY N OF SAN DIEGO COUNTY...COULD HAVE SEVERAL INCHES
BASED ON CURRENT STORM TRACK PROJECTIONS. THE THERMAL GRADIENTS WILL
BE MOSTLY NORTH OF OUR AREA...SO SNOW LEVELS SHOULD BE HIGH WITH
THIS SYSTEM.
BOTH THE ECM AND GFS MOVE OUT THE MOISTURE ON MON...ALLOWING RIDGING
TO DEVELOP OVER THE AREA. DRY AND MILD WEATHER IS EXPECTED MUCH OF
THE WEEK AS THE RIDGE IS FORECAST TO HOLD.
&&
.AVIATION...
100345Z...MID-HIGH LEVEL CLOUDS AOA FL150 WILL MOVE OVER THE AREA
THROUGH THURSDAY AND GRADUALLY LOWER TO AROUND FL080. STRATUS
IS EXPECTED TO RETURN LATE THURSDAY NIGHT WITH CIGS BETWEEN
3500-5000 FT MSL AS A LOW PRESSURE SYSTEM APPROACHES FROM THE WEST.
&&
.MARINE...
100350Z...A LARGE LONG PERIOD WEST NORTHWEST SWELL WILL IMPACT THE
BEACHES THROUGH FRIDAY WITH SURF 5 TO 7 FEET WITH SETS UP TO 10
FEET. THERE IS A HIGH SURF ADVISORY THROUGH FRIDAY AFTERNOON. THE
SWELL WILL BE UP TO AROUND 6 TO 8 FEET IN THE INNER WATERS TO 7 TO 9
FEET IN THE OUTER WATERS. THE HIGH SURF WILL ALSO GENERATE STRONG
RIP CURRENTS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY...SEE LAXCFWSGX.
HYDROLOGIC OUTLOOK...SEE LAXESFSGX.
&&
$$
PUBLIC...MAXWELL
AVIATION/MARINE...SULLIVAN
