Area Forecast Discussion
Issued by NWS San Diego, CA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS66 KSGX 202151 AFDSGX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN DIEGO CA 145 PM PST THU NOV 20 2014 .SYNOPSIS... A TROUGH OF LOW PRESSURE WILL MOVE SOUTHEAST THROUGH CALIFORNIA TONIGHT AND FRIDAY MORNING...BRINGING SCATTERED LIGHT SHOWERS ALONG AND WEST OF THE MOUNTAINS AND SOME LOCALLY GUSTY WINDS FOR THE MOUNTAINS AND DESERTS. DRY BUT COOL WEATHER WILL FOLLOW THROUGH THE WEEKEND. SURFACE HIGH PRESSURE OVER THE GREAT BASIN WILL RESULT IN DRY OFFSHORE FLOW DEVELOPING NEXT WEEK FOR FAIR AND WARMER WEATHER. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... ANOTHER BEAUTIFUL SOUTHERN CALIFORNIA DAY WITH HIGH TEMPERATURES NEAR TO SLIGHTLY BELOW SEASONAL AVERAGES. HIGH CLOUD COVER IS INCREASING THIS AFTERNOON WITH THE ADDITION OF SCATTERED LOW CLOUDS WEST OF THE MOUNTAINS. CLOUD COVER WILL CONTINUE TO INCREASE THROUGH THIS EVENING AS THE UPPER LEVEL TROUGH OFF THE NORCAL COAST MOVES THROUGH CALIFORNIA. THIS TROUGH WILL BRING MOSTLY LIGHT SHOWERS TONIGHT THROUGH FRIDAY MORNING...WITH THE BULK OF THE PRECIPITATION FALLING EARLY FRIDAY MORNING. RAINFALL AMOUNTS WILL BE MOSTLY LIGHT...ONE-TENTH OF AN INCH OR LESS...WITH A FEW AREAS UP TO ONE-QUARTER OF AN INCH ALONG THE FAVORED UPSLOPE AREAS OF THE COASTAL MOUNTAINS. THE SNOW LEVEL WILL DROP TO AROUND 7000 FEET...BUT SNOW AMOUNTS WILL BE ONLY AROUND ONE HALF INCH OR LESS DUE TO LIMITED MOISTURE AT THAT ALTITUDE. GUSTY WEST WINDS WILL ALSO ACCOMPANY THIS SYSTEM...THOUGH WITH MAX GUSTS ONLY AROUND 35 TO 40 MPH...A WIND ADVISORY WILL NOT BE NEEDED. PRECIPITATION WILL TAPER OFF FRIDAY AFTERNOON AS THE SYSTEM EXITS OUT TO THE EAST. AS WE HEAD INTO THE WEEKEND...A STRONG JET STREAM WILL EXTEND THROUGH THE WEST SETTING UP PERSISTENT DRY AND COOL NORTHWEST FLOW ALOFT WITH A FEW WEAK EMBEDDED SHORTWAVES. THIS COMBINATION WILL SERVE TO KEEP GUSTY WINDS GOING FOR THE MOUNTAINS AND DESERTS THROUGH SUNDAY. WEST TO NORTHWEST WINDS WILL BE MODERATELY STRONG IN THESE AREAS WITH GUSTS 45 TO 50 MPH...LOCALLY UP TO 55 MPH IN THE WIND PRONE LOCATIONS...MAINLY SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON. THEREFORE A WIND ADVISORY WILL LIKELY BE NEEDED FOR THAT TIME. FOR MONDAY AND TUESDAY...SURFACE HIGH PRESSURE BUILDS OVER THE GREAT BASIN RESULTING IN WEAK TO MODERATE OFFSHORE FLOW FOR SOUTHERN CALIFORNIA. THIS WILL RAISE DAYTIME TEMPERATURES INTO THE MID-70S WEST OF THE MOUNTAINS...WITH SOME INLAND VALLEY LOCATIONS REACHING INTO THE LOW 80S FOR TUESDAY. EAST WINDS WILL BE STRONGEST EARLY EACH MORNING WITH THE HIGHEST WINDS BEING EARLY TUESDAY MORNING GUSTING UP TO 35 MPH ON THE COASTAL MOUNTAIN SLOPES AND IN THE FAR WESTERN VALLEYS...ESPECIALLY IN SAN DIEGO COUNTY WHERE LOCAL GUSTS COULD REACH 45 MPH. FOR THE LATTER HALF OF NEXT WEEK...THE MODELS CONTINUE TO BE IN ALMOST COMPLETE OPPOSITION. THE GFS HOLDS ON TO A RIDGE WITH UNSEASONABLY WARM WEATHER...WHILE THE ECMWF DROPS A COLD TROUGH OUT OF CANADA WITH COLDER WEATHER AND A CHANCE FOR PRECIPITATION. WITH THE ONGOING MODEL UNCERTAINTIES...WILL KEEP THE FORECAST AS A COMPROMISE BETWEEN THE TWO WITH A COOLING TREND BUT REMAINING DRY. && .AVIATION... 202130Z...COASTS/VALLEYS...VFR CONDITIONS THROUGH THIS AFTERNOON. BKN/OVC LOW CLOUDS...WITH BASES AROUND 2500 FT MSL AND TOPS RISING TO AROUND 6000 FT MSL...WILL DEVELOP WEST OF THE MOUNTAINS EARLY THIS EVENING. -SHRA WILL BE POSSIBLE TONIGHT AS A SYSTEM MOVES ACROSS THE AREA. VISIBILITY OF 3-5 SM WILL BE POSSIBLE IN SHOWERS TONIGHT. CONDITIONS WILL IMPROVE BY EARLY FRIDAY AFTERNOON. MOUNTAINS/DESERTS...UNRESTRICTED VIS AND INCREASING CLOUDS AOA 8000 FT MSL THIS AFTERNOON. STRATUS MAY OBSCURE LOWER COASTAL MOUNTAIN SLOPES TONIGHT. WESTERLY WIND GUSTS TO 40 KT WILL DEVELOP TONIGHT INTO FRI MORNING ALONG DESERT MOUNTAIN SLOPES AND ADJACENT DESERTS. && .MARINE... 130 PM...BREEZY WEST-NORTHWEST WINDS AROUND 20-25 KNOTS WILL DEVELOP FRIDAY IN THE OUTER COASTAL WATERS AS A SYSTEM MOVES ACROSS THE AREA. SIMILAR WINDS ARE POSSIBLE SATURDAY EVENING THROUGH SUNDAY MORNING AS ANOTHER DISTURBANCE MOVES ACROSS THE REGION. A SMALL CRAFT ADVISORY FOR WINDS HAS BEEN ISSUED FOR THE OUTER WATERS. OTHERWISE...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH TUESDAY. && .BEACHES... 130 PM...HIGH SURF...WITH SETS TO 6-8 FT...WILL CONTINUE ALONG SAN DIEGO AND ORANGE COUNTY BEACHES THROUGH THIS AFTERNOON. HIGHEST SURF WILL CONTINUE ALONG WESTERLY FACING BEACHES. A HIGH SURF ADVISORY CONTINUES THROUGH 5 PM TODAY. SWELL AND SURF WILL DECREASE TONIGHT INTO FRIDAY. && .SKYWARN... SKYWARN ACTIVATION WILL NOT BE NEEDED TODAY. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...HIGH SURF ADVISORY UNTIL 5 PM PST THIS AFTERNOON FOR THE ORANGE COUNTY COASTAL AREAS...SAN DIEGO COUNTY COASTAL AREAS. PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 10 PM THIS EVENING TO 4 PM PST FRIDAY FOR THE WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING 30 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND. && $$ PUBLIC...TS/JJT AVIATION/MARINE/BEACHES...JJT

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.