Expires:No;;297758 FXUS66 KSGX 271647 CCA AFDSGX AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE SAN DIEGO CA 847 AM PST FRI NOV 27 2009 .SYNOPSIS...HIGH PRESSURE ALOFT WEAKENS AS A TROUGH DROPS DOWN THE STATE TODAY. AN UPPER LEVEL LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP WITH THE TROUGH AND MOVE OVER SOUTHERN CALIFORNIA SATURDAY. THE MARINE LAYER WILL DEEPEN RAPIDLY TODAY WITH LOW CLOUDS MOVING OVER THE COAST THIS AFTERNOON. SHOWERS ARE POSSIBLE TONIGHT THROUGH SATURDAY WITH SNOW IN THE HIGHER ELEVATIONS. AN OFFSHORE FLOW DEVELOPS SUNDAY AND INCREASES SUNDAY NIGHT THROUGH MONDAY MORNING... DECREASING MONDAY AFTERNOON. HIGH PRESSURE ALOFT MOVES OVER LATE SUNDAY THROUGH MONDAY...WEAKENING TUESDAY WITH LITTLE CHANGE THROUGH THURSDAY. && .DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO... ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES. WEAK OFFSHORE FLOW CONTINUES THIS MORNING BETWEEN THE GREAT BASIN AND THE COAST BUT IS TRENDING ONSHORE AND SHOULD BECOME ONSHORE THIS AFTERNOON. ALREADY AREAS OF FOG OVER THE COASTAL WATERS WHICH SHOULD REACH THE BEACHES THIS AFTERNOON. COULD BE A BRIEF PERIOD OF DENSE FOG AT THE BEACHES AND ALONG THE COAST AS THE FOG MOVES ONSHORE BUT SHOULD LIFT INTO A STRATUS LAYER FAIRLY RAPIDLY THIS EVENING. SATELLITE PHOTOS SHOW THE COLD FRONT MOVING SOUTHEAST THROUGH CENTRAL CALIFORNIA HOLDING TOGETHER FAIRLY WELL AS IT MOVES SOUTH BUT LOOKING AT QPF AMOUNTS UP NORTH...PRECIPITATION AMOUNTS APPEAR TO BE QUITE LIGHT. HOWEVER...MODELS CONTINUE TO SO THE ASSOCIATED UPPER LOW MOVING SOUTH WITH THE FRONT TO BE MOVING DOWN THE COAST AND COULD PICK UP A LITTLE MORE MOISTURE THE FLOW MOVES ACROSS THE SOUTHERN CALIFORNIA COASTAL WATERS. STILL LOOKS LIKE AMOUNTS SHOULD BE A TENTH OF AN INCH OR LESS ALONG THE COAST AND INLAND VALLEY AREAS AND A QUARTER INCH IN THE MOUNTAINS. THE 12Z NAM CONTINUES THE IDEA OF EARLIER MODEL RUNS WITH THE UPPER LOW MOVING SOUTHEAST OF THE AREA INTO NORTHERN BAJA ON SUNDAY. THIS COULD BRING ENOUGH WRAP AROUND MOISTURE TO THE NORTHERN SLOPES OF THE MOUNTAINS TO CONTINUE SOME CLOUDS AND SHOWERS IN THOSE AREAS AT LEAST INTO SUNDAY MORNING. TIME HEIGHT CROSS SECTION FOR THE SAN DIEGO AREA CONTINUES MOISTURE INTO SUNDAY EVEN WITH THE DEVELOPING OFFSHORE FLOW SO NOT EXPECTING A RAPID DRYING OUT ON SUNDAY. MEDIUM RANGE MODELS CONTINUE TO SHOW DRY CONDITIONS THROUGH THE MIDDLE OF NEXT WEEK BEFORE ANOTHER SHORTWAVE MOVINGS SOUTH LATE IN THE WEEK. && .AVIATION... 271545Z...EXPECT RAPID RETURN OF MARINE LAYER TODAY AND INCREASING SOUTHWEST WINDS OVER MOUNTAINS AND DESERTS. ALREADY HAVE SCATTERED STRATUS LAYER OVER WATER APPROACHING COAST. STRATUS LAYER SPREADING INLAND AFTER 0000 UTC REACHING LOWER COASTAL SLOPES BY 0600 UTC. VERY LOW CEILINGS AND VISIBILITY COULD BRIEFLY IMPACT THE COASTAL AIRPORTS THIS AFTERNOON AND INLAND AIRPORTS DURING EVENING HOURS. MOUNTAINS BECOMING OBSCURED AFTER 0600 UTC AS MARINE LAYER MOISTURE DEEPENS AND MERGES WITH MOISTURE ASSOCIATED WITH APPROACHING TROUGH. NEAR SATURATED AIR MASS EXPECTED BELOW FL090 BY 0900 UTC. SOUTHWEST WINDS 35 TO 60 KT IN THE FL100-FL150 LAYER SHOULD RESULT IN MOUNTAIN WAVE ACTIVITY OVER DESERTS. AIR MASS STILL NEAR SATURATED BELOW FL090 SATURDAY AND FREEZING LEVEL LOWERING TO FL060. && .MARINE... SURF HEIGHTS 5 TO 10 FEET BEING REPORTED OVER SOUTHERN SAN DIEGO COUNTY BEACHES THIS MORNING. INNER BUOYS SHOW +6 FEET AT 17 SECONDS WHILE OUTER BUOYS ARE BOUNCING BETWEEN 8 AND 10 FEET. SWELL/SURF HEIGHTS STILL FORECAST TO INCREASE ANOTHER 2 TO 4 FEET BASED ON WAMIII MODEL. UPDATED SURF FORECAST AND WILL BE ADDING SMALL CRAFT ADVISORY TO INNER WATERS FOR TONIGHT AND SATURDAY DUE TO COMBINED SEAS ABOVE 10 FEET. && .SGX WATCHES/WARNINGS/ADVISORIES... CORRECTED CA...HIGH SURF ADVISORY UNTIL 2 PM PST SUNDAY FOR ORANGE COUNTY COASTAL AREAS. HIGH SURF ADVISORY UNTIL 2 PM PST SUNDAY FOR SAN DIEGO COUNTY COASTAL AREAS. PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 2 PM THIS AFTERNOON TO 8 AM PST SUNDAY FOR WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING 30 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM MIDNIGHT TONIGHT TO MIDNIGHT PST SATURDAY NIGHT FOR COASTAL WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER AND OUT 30 NM. && $$ PUBLIC...HORTON AVIATION/MARINE...BALFOUR