FXUS66 KSGX 262139
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
200 PM PST SAT DEC 26 2009
.SYNOPSIS...THE SHALLOW MARINE LAYER WILL CAUSE PATCHY FOG NEAR THE
COAST DURING THE NIGHTS AND MORNINGS THROUGH SUNDAY. UPPER LEVEL LOW
PRESSURE APPROACHING FROM THE NORTHWEST WILL MOVE THROUGH MONDAY AND
TUESDAY. THIS WILL BRING VARIABLE CLOUDINESS WITH A SLIGHT CHANCE OF
LIGHT SHOWERS SUNDAY NIGHT THROUGH TUESDAY NIGHT. DECREASING CLOUDS
LATER NEXT WEEK IN DRIER NORTHWEST FLOW ALOFT.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
TODAY THROUGH TUESDAY...A FEW LOW CLOUDS LINGER THIS AFTERNOON OVER
THE COASTAL AREAS WITH MID AND HIGH CLOUDS INCREASING AS AN UPPER
LEVEL TROUGH APPROACHES FROM THE NW. RECENT AIRCRAFT SOUNDINGS SHOW
A WEAK INVERSION AT ABOUT 1500 FT WITH LIGHT SOUTHERLY WINDS BLO
10000 FT AND INCREASING NW WINDS ABV. SFC PRESSURE GRADIENTS
CONTINUE TO TREND ONSHORE. THE MARINE LAYER SHOULD LIFT A BIT
TONIGHT AND WILL BE DISRUPTED BY HIGHER CLOUDS. THE HIGH CLOUDS WILL
CONTINUE TO INCREASE AS THE TROUGH MOVES IN FORM THE NW. THIS TROUGH
WILL WEAKEN AS IT PUSHES THE UPPER RIDGE TO THE E AND SPLITS AS IT
MOVES ONSHORE WITH MUCH OF THE ENERGY GOING INTO NRN BAJA. LOW
LEVELS IN MOST AREAS WILL REMAIN FAIRLY DRY WITH WEAK OFFSHORE FLOW
RETURNING FOR A TIME ON MONDAY. HOWEVER...THERE WILL BE MORE MID AND
HIGH LEVEL MOISTURE AND LOW ENOUGH HEIGHTS FOR A SMALL CHANCE OF
LIGHT PRECIP LATE SUNDAY THROUGH MONDAY. TEMPS WILL REMAIN A LITTLE
BELOW SEASONAL AVERAGES IN MOST AREAS. THERE COULD BE A LITTLE
WARMING W OF THE MOUNTAINS MONDAY IN THE WEAK LOW LEVEL OFFSHORE
FLOW. A SHORT WAVE WILL MOVE SWD INTO SRN CA TUESDAY ON THE W SIDE
OF THE DEPARTING TROUGH. THIS WILL MAINTAIN A SMALL CHANCE OF LIGHT
PRECIP THROUGH TUESDAY.
WEDNESDAY THROUGH SATURDAY... GENERALLY DRY AND WEAKLY CYCLONIC NW
FLOW ALOFT WILL PREVAIL WEDNESDAY AND THURSDAY WITH VARIABLE HIGH
CLOUDINESS. WEAK RIDGING FRIDAY AND SATURDAY FOR FAIR WEATHER.
GRADUALLY WARMER DURING THE SECOND HALF OF NEXT WEEK WITH MAX TEMPS
REACHING NEAR SEASONAL THURSDAY THROUGH SATURDAY.
&&
.AVIATION...
262115Z...A WEAK INVERSION BASE WAS AROUND 2000 FT MSL THIS
AFTERNOON. THIS WILL RESULT IN SCT/LOCALLY BKN CONDITIONS NEAR THE
COAST AT THAT HEIGHT TONIGHT INTO SUNDAY MORNING. PATCHY VIS BELOW 5
MILES WILL OCCUR...THOUGH NO DENSE FOG IS EXPECTED TONIGHT/EARLY
SUNDAY. ABOVE THE MARINE LAYER...MOSTLY BKN CLOUDS ABOVE FL150 WILL
OCCUR THROUGH SUNDAY.
&&
.MARINE...
262115Z...A LARGE...LONG PERIOD WEST SWELL IS FORECAST TO MOVE INTO
THE COASTAL WATERS SUN THROUGH TUE DUE TO A DEEP NORTH PACIFIC STORM
THAT HAS BEEN OCCURRING THE PAST FEW DAYS. A HIGH SURF ADVISORY WILL
BE ISSUED THIS AFTERNOON FOR SUNDAY AFTERNOON THROUGH MONDAY. SURF
WILL BE ABOVE NORMAL INTO TUESDAY BUT PROBABLY BELOW HIGH SURF
ADVISORY CRITERIA.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH SURF ADVISORY FROM NOON SUNDAY TO 10 PM MONDAY FOR ORANGE
COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS...SEE
LAXCFWSGX.
&&
$$
PUBLIC...PG
AVIATION/MARINE...MAXWELL
