NWS Forecast Discussion
000 FXUS66 KSGX 182019 AFDSGX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN DIEGO CA 200 PM PDT THU MAR 18 2010 .SYNOPSIS...A DEVELOPING MARINE LAYER WILL BRING AREAS OF COASTAL LOW CLOUDS AND FOG FRIDAY MORNING THROUGH THE WEEKEND. OFFSHORE FLOW WILL CAUSE LOCAL GUSTY WINDS THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES FRIDAY. A LITTLE WARMER THROUGH THE WEEKEND UNDER HIGH PRESSURE. ANOTHER LOW WILL BRING MORE CLOUDS AND COOLING EARLY NEXT WEEK. && .DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO... ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES. THIS AFTERNOON THROUGH SUNDAY...RECENT AIRCRAFT SOUNDINGS SHOWED THE MARINE LAYER HAS DEEPENED TO AROUND 1000 FEET. GRADIENTS CONTINUE TO TREND ONSHORE. THE COASTAL EDDY HAS STRENGTHENED AND THE STRATUS HAS MOVED OVER A FEW SPOTS ALONG THE SAN DIEGO COUNTY BEACHES. ELSEWHERE...MOSTLY CLEAR BUT COOLER W OF THE MOUNTAINS UNDER A WEAK UPPER LOW WITH STRONGER ONSHORE FLOW. THE EDDY WILL DEEPEN THE MARINE LAYER THROUGH TONIGHT...ALLOWING THE STRATUS TO MOVE INLAND BY FRIDAY MORNING. WEAK TO LOCALLY MODERATE OFFSHORE FLOW WILL DEVELOP IN THE WAKE OF UPPER TROUGH ON FRIDAY. THE OFFSHORE FLOW WILL CAUSE LOCAL GUSTY WINDS THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES WHICH COULD BRIEFLY REACH ADVISORY STRENGTH WITH GUSTS OVER 35 MPH FRIDAY. HOWEVER...THE OFFSHORE FLOW MAY NOT BE STRONG ENOUGH TO CLEAR OUT THE STRATUS NEAR THE COAST FRIDAY MORNING...ESPECIALLY IN SAN DIEGO COUNTY. WARMER IN SOME AREAS W OF THE MOUNTAINS FRIDAY...EXCEPT NEAR THE IMMEDIATE COAST. COLD AIR ADVECTION WILL BRING COOLING TO THE MOUNTAINS AND DESERTS FRIDAY. WARMER IN MOST AREAS WITH A DECREASING MARINE LAYER SATURDAY AND SUNDAY UNDER HIGH PRESSURE. MONDAY THROUGH THURSDAY...A TROUGH APPROACHING FROM THE NW WILL BRING MORE HIGH CLOUDS AND COOLING MONDAY. DEEPER MARINE LAYER MONDAY NIGHT AND TUESDAY MORNING. THE UPPER LOW WILL MOVE THROUGH TUESDAY AND COULD PRODUCE LIGHT PRECIP. HOWEVER...CHANCES ARE LOW ENOUGH TO KEEP PRECIP OUT OF THE FORECAST AS THERE IS NOT MUCH DEEP LAYER MOISTURE. COOLER STILL ON TUESDAY. DECREASING CLOUDINESS AND WARMER WEDNESDAY AND THURSDAY AS THE TROUGH MOVES E AND HIGH PRESSURE BUILDS ALOFT. && .AVIATION... 181900Z...MARINE LAYER DEEPENED TO AROUND 1100 FEET AFTER SUNRISE THIS MORNING AND SHOULD DEEPEN TO AROUND 2000 FEET THIS EVENING AND OVERNIGHT BEFORE LOWERING...AGAIN...ON FRIDAY TO AROUND 1000 FEET. AREAS OF STRATUS ALONG THE COAST FROM KNZY SOUTHWARD WITH BASES AROUND 1000 FEET MSL SHOULD SPREAD NORTH THROUGH THE AFTERNOON AND INLAND THIS EVENING. STRATUS SHOULD BREAK UP ON FRIDAY AFTER SUNRISE AS OFFSHORE FLOW DEVELOPS OVER THE AREA. ABOVE THE MARINE LAYER...A MOSTLY CLEAR SKY WITH UNRESTRICTED VISIBILITIES WILL CONTINUE THROUGH FRIDAY. HORTON && .SGX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...PG AVIATION...HORTON
NWS SGX Office Area Forecast Discussion