NWS Forecast Discussion
000 FXUS66 KSGX 202026 AFDSGX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN DIEGO CA 200 PM PDT SAT MAR 20 2010 .SYNOPSIS...FAIR AND WARM THIS WEEKEND UNDER HIGH PRESSURE AND WEAK OFFSHORE FLOW. A LITTLE COOLER ON MONDAY...THEN ON TUESDAY A TROUGH OF LOW PRESSURE WILL BRING MORE COOLING ALONG WITH INCREASING CLOUDS AND GUSTY WINDS TO THE MOUNTAINS AND DESERTS. WEAK HIGH PRESSURE WILL REBUILD FOR MORE WARM DRY WEATHER WEDNESDAY AND THURSDAY...THEN A LITTLE COOLER AGAIN NEXT FRIDAY AND SATURDAY. && .DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO... ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES. MOSTLY CLEAR THIS AFTERNOON...EXCEPT FOR SOME SHALLOW MARINE LAYER CLOUDS AND FOG LINGERING OVER THE COASTAL WATERS...AS WELL AS SOME HIGH CLOUDS STREAMING OVER SOCAL FROM THE NW. SURFACE PRESSURE GRADIENTS TRENDING OFFSHORE HAVE PRODUCED SOME GUSTY EASTERLY WINDS IN THE RIVERSIDE AND SAN DIEGO COUNTY MOUNTAINS...BUT EXPECT THE WINDS TO WEAKEN OVERNIGHT. THE OFFSHORE FLOW WILL ALSO PUSH THE MARINE LAYER OUT TO SEA TONIGHT...BUT THE SHALLOW MARINE LAYER WITH LOW CLOUDS AND FOG COULD RETURN TO THE COASTAL AREAS LATE TONIGHT INTO SUNDAY MORNING...ESPECIALLY IF THE COALTAL EDDY NOW DEVELOPING PERSISTS THROUGH TONIGHT. SUNDAY WILL BE WARMER IN IN THE MTNS AND DESERTS AS THE COLD AIR ADVECTION WEAKENS...AND COOLER WEST OF THE MTNS AS THE UPPER RIDGE AND THE OFFSHORE FLOW BOTH WEAKEN ALLOWING A STRONGER SEA BREEZE TO DEVELOP TOMORROW. ON SUNDAY NIGHT AND MONDAY...THE UPPER LEVEL RIDGE IS WEAKENED BY A SPLIT FLOW TROUGH THAT WILL BRING EVEN COOLER WEATHER MONDAY AND TUESDAY. THE MODELS COME INTO FAIRLY GOOD AGREEMENT...WITH BOTH THE ECM AND THE GFS INDICATING A COOL BREEZY DAY WITH A DEEPENING MARINE LAYER ON TUESDAY. WEDNESDAY THROUGH SATURDAY...A WEAK UPPER RIDGE REBUILDS OVER CALIFORNIA AS THE TROUGH MOVES EAST...BRINGING FAIR SKIES AND SOME WARMING ON WED AND THU. ANOTHER LOW PRESSURE TROUGH MOVES IN FROM THE NW TO AGAIN BRING SOME CLOUDS AND LOWER TEMPS FRIDAY AND SATURDAY. && .AVIATION... 202130Z...SCT-BKN LOW CLOUDS BASED 300-500 FEET MSL WITH TOPS AROUND 800 FEET MSL OVER THE COASTAL WATERS OTHERWISE MOSTLY CLEAR WITH UNRESTRICTED VISIBILITIES. AFTER 06Z SCT-BKN LOW CLOUDS OVER THE COASTAL WATERS AND REACHING INLAND ABOUT 10 MILES...WITH BASES 300-500 FEET MSL AND TOPS AROUND 800 FEET MSL. AREAS OF VISIBILITIES BELOW 3SM WITHIN 10 SM OF THE COASTLINE...AND LOCALLY 1/2SM IN DENSE FOG. SMALL && .SGX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...PG AVIATION...SMALL
NWS SGX Office Area Forecast Discussion