Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 03/17/16


AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
841 AM PDT THU MAR 17 2016 .SYNOPSIS... WEAK ONSHORE FLOW WILL CREATE SOME COOLING WEST OF THE MOUNTAINS TODAY...WHILE THE DESERTS HEAT UP. HOWEVER...IT WILL STILL BE WARMER THAN NORMAL IN ALL AREAS TODAY THROUGH SUNDAY AS A RIDGE OF HIGH PRESSURE BUILDS ALOFT. NIGHT AND MORNING LOW CLOUDS AND FOG LIKELY TO OCCUR IN THE COAST AND WESTERN VALLEYS THROUGH SUNDAY...WITH OTHERWISE MOSTLY CLEAR SKIES EXCEPT FOR SOME HIGH CLOUDS PASSING OVER THE REGION THIS WEEKEND. COOLER MONDAY WITH STRENGTHENING ONSHORE FLOW AND A DEEPER MARINE LAYER. A TROUGH OF LOW PRESSURE MOVING INTO THE GREAT BASIN COULD CREATE CONTINUED COOLING...INCREASING CLOUDS...SOME LIGHT PRECIPITATION OVER AND WEST OF THE MOUNTAINS...AND STRONG AND GUSTY WEST WINDS IN THE MOUNTAINS AND DESERTS TUESDAY AND POSSIBLY INTO WEDNESDAY. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... A SHALLOW MARINE LAYER HAS MADE ITS PRESENCE KNOWN THIS MORNING...WITH LOCAL DENSE FOG BEING REPORTED ALONG THE SAN DIEGO COUNTY COAST. VISIBLE SATELLITE SHOWS THE MARINE LAYER FOG AND LOW CLOUDS ABOUT 5 MILES INLAND FROM THE SOUTHERN SAN DIEGO COUNTY COAST AND OVER THE NEARSHORE WATERS. AIRCRAFT SOUNDINGS SHOW A 5 DEGREE MARINE LAYER INVERSION AT AROUND 1000-1100 FEET ABOVE MEAN SEA LEVEL. LOW CLOUDS AND FOG SHOULD CLEAR OUT BY MID-TO-LATE MORNING...MAKING WAY FOR A MOSTLY SUNNY DAY ACROSS THE REGION. WATER VAPOR SATELLITE SHOWS AN UPPER LEVEL RIDGE ALONG THE WEST COAST...WITH A LOW PRESSURE SYSTEM OVER THE NORTHEAST PACIFIC SOUTH OF THE ALEUTIAN ISLANDS. PRESSURE GRADIENTS ARE TRENDING ONSHORE THIS MORNING...WITH THE SAN DIEGO TO TONOPAH GRADIENT INDICATING 4.7 MB OFFSHORE...WHILE IT WAS 7.9 MB OFFSHORE AT THIS TIME YESTERDAY. THUS...WE SHOULD GET A GOOD SEA BREEZE TODAY AND COOLER CONDITIONS OVER THE COAST AND VALLEYS...WHILE THE DESERTS HEAT UP. MODELS INDICATE THE FLOW TURNING COMPLETELY ONSHORE TONIGHT INTO FRIDAY MORNING...WITH LOW CLOUDS/FOG MOVING INTO THE COAST AND WESTERN VALLEYS. THE UPPER LEVEL RIDGE SLOWLY BUILDS OVER THE REGION FRIDAY THROUGH SUNDAY...WITH WEAK ONSHORE FLOW...NIGHT AND MORNING LOW CLOUDS/FOG ALONG THE COAST/WESTERN VALLEYS...AND WARMER THAN NORMAL WEATHER CONTINUING. ON MONDAY...MODELS INDICATE A TROUGH MOVING INTO THE PACIFIC NORTHWEST...WITH INCREASING ONSHORE FLOW...COOLING AND A DEEPENING MARINE LAYER FOR SOUTHERN CALIFORNIA. MODELS THEN SHOW THE TROUGH AMPLIFYING AND MOVING SOUTH INTO THE GREAT BASIN REGION TUESDAY AND POSSIBLY INTO WEDNESDAY...CREATING MORE COOLING...INCREASING CLOUDS...STRONG AND GUSTY WEST WINDS IN THE MOUNTAINS AND DESERTS...AND CHANCES FOR LIGHT SHOWERS OVER AND WEST OF THE MOUNTAINS. THE GFS IS MORE PROGRESSIVE AND DRIER WITH THE TROUGH...AS IT SWINGS IT THROUGH THE GREAT BASIN TUESDAY AND MOVES IT OFF TO THE EAST WEDNESDAY WITH AN UPPER LEVEL RIDGE BUILDING IN BEHIND IT. THE GFS ALSO SHOWS A PLUME OF 0.7 INCH PRECIPITABLE WATER DIRECTED AT SOUTHERN CALIFORNIA ON TUESDAY. THE ECMWF...ON THE OTHER HAND...IS MORE AMPLIFIED AND SLOWER WITH THE TROUGH PROGRESSION...AS IT KEEPS THE TROUGH OVER THE REGION INTO WEDNESDAY...RESULTING IN PERIODS OF LIGHT PRECIPITATION TUESDAY AND WEDNESDAY. AS FAR AS THE WINDS IN THE MOUNTAINS AND DESERTS...WESTERLY 850 MB WINDS OF 25-35 KT ARE INDICATED...WHICH COULD BE ENOUGH TO CREATE WIND GUSTS OF 50-60 MPH. DRY WEATHER LIKELY NEXT THURSDAY INTO FRIDAY WITH POSSIBLE OFFSHORE FLOW AND A BUILDING RIDGE ALOFT. && .AVIATION... 171530Z...AREAS OF LOW CLOUDS WITH BASES AROUND 600 FT MSL AND TOPS AROUND 1100 FT MSL...AND FOG WITH LOCAL VIS BELOW 3SM REMAIN ALONG THE IMMEDIATE COAST THIS MORNING. EXPECT THE LOW CLOUDS AND FOG TO BE PUSHED OFFSHORE BY 17Z. MORE WIDESPREAD CLOUDS AND FOG ARE LIKELY THIS EVENING INTO FRIDAY MORNING. LOW CLOUDS WITH BASES BELOW 900 FT MSL AND AREAS OF VIS BELOW 2 SM ARE EXPECTED AFTER 02Z FRI...SPREADING 10-15 MILES INLAND OVERNIGHT. VIS MAY LOWER TO 1/2 SM OR LESS OVERNIGHT...ESPECIALLY OVER HIGHER COASTAL TERRAIN AND COASTAL MESAS. THERE IS A CHANCE THAT LOW CLOUDS AND FOG COULD IMPACT KONT AFTER 10Z FRI...BUT CONFIDENCE IS LOW AT THIS TIME. ELSEWHERE...MOSTLY CLEAR WITH UNRESTRICTED VISIBILITY THROUGH FRIDAY. && .MARINE... 830 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH SUNDAY. && .SKYWARN... SKYWARN ACTIVATION WILL NOT BE NEEDED TODAY. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC...HARRISON AVIATION/MARINE...PG