958 FXUS66 KSGX 091741 AAA AFDSGX AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE SAN DIEGO CA 942 AM PST SAT FEB 9 2013 .SYNOPSIS... LOW PRESSURE ALOFT OVER THE SOUTHWEST STATES WILL MOVE EAST THROUGH SUNDAY. HOWEVER...SOME MOISTURE WILL LINGER...AND IT WILL REMAIN SEASONALLY COOL. THE MOIST AND COOL CONDITIONS WILL LEAD TO MORE NIGHTTIME FOG AND AREAS OF FROST TONIGHT AND AGAIN ON SUNDAY NIGHT. GRADUAL WARMING THROUGH NEXT WEEK WITH LOCALLY GUSTY NORTH WINDS DEVELOPING NEAR THE COASTAL FOOTHILLS SUNDAY AND MONDAY. STRONGER NORTHEAST WINDS ARE POSSIBLE AGAIN ON THURSDAY AND FRIDAY AS A LARGE AREA OF HIGH PRESSURE REBUILDS OVER THE GREAT BASIN. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... SKIES HAD CLEARED WEST OF THE MOUNTAINS EARLY THIS MORNING...EXCEPT FOR PATCHY FOG...BUT SATELLITE IMAGERY SHOWED SOME CLOUDS LINGERING NEAR THE COASTAL MOUNTAIN SLOPES. AT LOWER ELEVATIONS...TEMPERATURES FELL INTO THE 30S WHERE SKIES CLEARED. IT WAS MUCH COLDER OVER THE MTNS WHERE RESORT TEMPS WERE IN THE TEENS. WINDS WERE STILL IN THE 20 TO 30 MPH RANGE OVER THE RIDGES AND DESERT SLOPES...SUPPORTED BY 4-6 MB ONSHORE GRADIENTS TO THE DESERTS. THE 12Z MIRAMAR SOUNDING SHOWED CONTINUED COOLING ABOVE 700 MBS AND A PROFILE CLOSE TO SATURATION BELOW 7K FT. A FAIRLY STEEP LAPSE RATE EXTENDED FROM THE SFC TO 500 MBS. GIVEN THE 12Z SOUNDING...EXPECT THE MOSTLY CLEAR SKIES WEST OF THE MTNS WILL GIVE WAY TO AREAS OF STRATOCU AS SFC HEATING BEGINS TO CONVECT THE DEEP MOIST LAYER. NO PCPN IS EXPECTED AT THIS TIME...BUT THE CLOUDS AND MOISTURE WILL RETARD ANY BIG WARM-UP FOR TODAY. THE CLOUDS WILL LIKELY REMAIN FAIRLY THICK ON THE COASTAL MTN SLOPES AS ONSHORE FLOW CONTINUES TO LIFT THE MOIST LAYER ONTO THE SLOPES. TONIGHT...THE MODELS HANG ONTO THE MOIST BOUNDARY LAYER AS A VERY WEAK SHORT-WAVE SLIDES SOUTH AROUND THE BACK SIDE OF THE LARGE UPPER-LOW OVER THE GREAT BASIN. MODELS ARE HINTING AT THE POSSIBILTY OF SOME SNOW FLURRIES IN THE MTNS OVERNIGHT AS IT MOVES THROUGH...BUT ANY ACCUMULATION SHOULD BE NEGLIGIBLE. OTHERWISE SKIES SHOULD BE MOSTLY CLEAR. THAT SHOULD RESULT IN AREAS OF FOG WEST OF THE MOUNTAINS...AND FROST WHERE WINDS STAY LIGHT...INCLUDING THE LOWER COACHELLA VALLEY. THE BACK SIDE OF THE HIGH AMPLITUDE TROUGH REMAINS OVER THE SW THROUGH MON...KEEPING ANY RISE IN HEIGHT/THICKNESS OVER CA MUTED. STILL...WE SHOULD SEE A MARGINAL INCREASE IN DAYTIME TEMPS. ONCE IT MOVES FAR ENOUGH TO THE EAST SUN NIGHT/MON...HIGH PRESSURE WILL BUILD OVER THE GREAT BASIN...AND THE NORTHERLY FLOW ALOFT SHOULD AID IN THE DEVELOPMENT OF LOCALLY GUSTY OFFSHORE WINDS THROUGH THE SAN BERNARDINO AND SANTA ANA MTN GAPS. THIS WILL BEING A DRY PUSH INTO THOSE AREAS FOR MON....WHICH WILL SPREAD SOUTH THROUGH THE DAY. BY TUE MORNING...OFFSHORE FLOW SHOULD HAVE PUSHED MOST OF THE LOW-LEVEL MOISTURE BACK OUT TO SEA. THIS SETS US UP FOR WARMER DAYS AS HIGH PRESSURE EXPANDS OVER THE EAST PACIFIC. A STRONGER SHORT-WAVE TROUGH IS FCST TO MOVE SOUTH THROUGH NV ON BOTH THE GFS/ECMWF MODELS THU. THIS ONE COULD GENERATE FAIRLY STRONG OFFSHORE FLOW IF THE 00Z ECMWF RUN VERIFIES...BUT THE OTHER GLOBAL MODELS AND ENSEMBLES ARE WEAKER. MAIN CONCERNS FOR THE NEXT 24 TO 36 HOURS WILL BE FOR AREAS OF DENSE FOG AND FROST OVERNIGHTS. NO ADVISORIES ARE OUT AT THIS TIME BUT ARE BEING CONSIDERED. && .AVIATION... 091630Z...AIR MASS STILL MOIST AND CONDITIONALLY UNSTABLE ACROSS SW CALIFORNIA. OVER AND NEAR MTNS...SCT-BKN CLOUDS BASES 2500-3500 FT MSL TOPS 8000 FT MSL AND ISOLD 2-3SM SHSN WITH TOPS TO 20000 FT MSL...OVER WATER/COASTAL AIRPORTS SCT CLDS BETWEEN 2500-5000 FT MSL WITH ISOLD SHRA-...DESERTS MOSTLY SKC. LITTLE CHANGE EXPECTED THROUGH 10/1600 UTC. && .MARINE... LOWERED SMALL CRAFT ADVISORY DUE TO LACK OF REPORTS OF MODERATE OR STRONGER WIND GUSTS AND RAPID DOWNWARD TREND IN COMBINED SEA HEIGHTS AT OUTER BUOYS. PLAN TO DROP THE COASTAL HAZARD ADVISORY SHORTLY AFTER 1000 PST UNLESS MORNING LIFEGUARD OBS COME IN WITH WIDESPREAD +7 FT SURF HEIGHTS. && .SGX WATCHES/WARNINGS/ADVISORIES...UPDATED CA...NONE. PZ...NONE. && $$ PUBLIC...JAD AVIATION/MARINE...BALFOUR