FXUS66 KMTR 161145 AFDMTR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 445 AM PDT SAT MAR 16 2013 .DISCUSSION...AS OF 4:30 AM PDT SATURDAY...FOG PRODUCT IMAGERY AND SFC OBS ARE INDC AREAS OF LOW CLOUDS AND FOG ACROSS THE COASTAL WATERS AND IN THE VALLEYS. THE 10Z MODIS IMAGERY IS INDC THAT THE DEPTH OF THE FOG/LOW CLOUDS IS LESS THAN 1000 FEET. A SHORTWAVE IN THE GULF OF ALASKA...WEST OF THE QUEEN CHARLOTTE ISLANDS...WILL MOVE INTO THE PACIFIC NORTHWEST TODAY...AND THEN DIVE SOUTHEAST INTO THE ROCKIES TONIGHT. THE MAIN EFFECT FOR THE DISTRICT WILL BE SLIGHTLY COOLER TEMPS...MAINLY INLAND. WEAK RIDGING WILL KEEP THE DISTRICT DRY RIGHT THROUGH MONDAY ALONG WITH PLEASANT TEMPERATURES. MUCH NEEDED RAIN WILL RETURN TO THE DISTRICT TUESDAY AS A SYSTEM NORTH OF THE HAWAIIAN ISLANDS MOVES TO THE COAST. THE ASSOCIATED COLD FRONT WILL BRING RAIN TO THE DISTRICT BY TUESDAY AFTN...WITH RAIN LIKELY TUESDAY NIGHT. BOTH THE ECMWF AND THE GFS WEAKEN THE SYSTEM AS IT MOVES TO THE COAST...SO WHEREAS RAIN IS LIKELY RAINFALL AMOUNTS WILL NOT BE IMPRESSIVE...GENERALLY LESS THAN ONE HALF INCH. RAIN WILL BECOME SHOWERY BY WEDNESDAY MORNING AS THE UPPER TROUGH MOVES ONTO THE COAST. ALL SHOWER ACTIVITY WILL END WEDNESDAY EVENING...IF NOT SOONER AS THE MEDIUM RANGE MODELS MOVE THIS SYSTEM FAIRLY QUICKLY OUT OF THE AREA. AS HAS BEEN THE COMMON REFRAIN SINCE THE BEGINNING OF THE YEAR RIDGING WILL BUILD RIGHT BACK ALONG THE COAST. THIS WILL RESULT IN DRY WEATHER FOR THE END OF THE WEEK AND INTO NEXT WEEKEND WITH TEMPERATURES WARMING TO ABOVE NORMAL. MOS GUIDANCE IS HINTING AT TEMPS REACHING THE MID 70S IN THE INLAND VALLEYS NEXT SATURDAY... WITH 80S POSSIBLE IN INTERIOR MONTEREY AND SAN BENITO COUNTIES. && .AVIATION...AS OF 10:48 PM PDT FRIDAY...FOR 06Z TAFS. FOG IMAGERY IS SHOWING STRATUS LAYER MAKING A RETURN TO THE COAST WITH HALF MOON BAY REPORTING 800 FOOT CIGS AND 5 MINUTE DATA OUT OF KSFO SHOWING OVERCAST 700 FEET ALREADY. GIVING ONSHORE TRENDS EXPECT CIGS TO FILTER INTO SF BAY AND MONTEREY BAY REGION OVERNIGHT AND INTO THE PRE-DAWN HOURS. LATEST PACKAGE WILL SHOW A BURN OFF AROUND 17Z GIVEN SYNOPTIC PATTERN THERE IS NO OBVIOUS REASON WHY THE LOW CIGS SHOULD STAY AROUND TOO MUCH LONGER. MEDIUM CONFIDENCE. VICINITY OF KSFO...LATEST OBS ALREADY SHOW OVERCAST 700 AT KSFO. EXPECT CIGS TO STAY IN OVERNIGHT THROUGH ABOUT 17Z SATURDAY MORNING. EXPECT GUSTY WEST WINDS AGAIN SATURDAY AFTERNOON. KSFO BRIDGE APPROACH...GIVEN SHALLOW NATURE NOT EXPECTING AS MUCH CIGS OVER SOUTHERN PART OF THE BAY SATURDAY MORNING. MONTEREY BAY AREA TERMINALS...IFR CIGS AT HALF MOON BAY FORECAST TO REACH KMRY AND KSNS OVERNIGHT...THEN SLOWLY MIX OUT BY LATE SATURDAY MORNING. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT REYES TO PIGEON PT 0-10 NM SCA...PIGEON PT TO PT PINOS 0-10 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...PT ARENA TO PT REYES 0-10 NM SCA...PT ARENA TO PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM SCA...SF BAY FROM 2 PM SCA...MRY BAY FROM 2 PM && $$ PUBLIC FORECAST: STROBIN AVIATION/MARINE: CW VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA  FXUS66 KMTR 161626 AFDMTR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 926 AM PDT SAT MAR 16 2013 .DISCUSSION...AS OF 9:30 AM PDT SATURDAY...POCKETS OF DENSE FOG AROUND OUR AREA THIS MORNING WITH SEVERAL OBSERVATION POINTS INDICATING VISIBILITIES AROUND A QUARTER OF A MILE. SATELLITE SHOWS AN INTERESTING SETUP WITH CLOUDS RIGHT AT THE COAST...BAYS...AND ADJACENT VALLEYS WHILE SPOTS MORE OFFSHORE ARE CLEAR. WITH 5 MB FROM THE NORTH AND JUST 1.5 FROM THE WEST STILL EXPECT THAT MOST SPOTS WILL CLEAR OUT BEFORE NOON. HIGHS IN MOST SPOTS WILL RANGE FROM UPPER 50S TO MID 60S AT THE COAST TO MID 60S TO LOWER 70S INLAND. MAIN FORECAST CONCERN REMAINS RAINFALL FOR TUESDAY AND WEDNESDAY. 12Z GFS OPERATIONAL RUN JUST IN CONTINUES TO BRING THE COLD FRONT THROUGH TUESDAY NIGHT SO FEEL FAIRLY GOOD ABOUT THE CURRENT PACKAGE. BOTH THE GFS AND ECMWF OVER THE PAST FEW DAYS HAVE BEEN IN GOOD AGREEMENT WITH THE UPCOMING SYSTEM. .PREVIOUS DISCUSSION...FOG PRODUCT IMAGERY AND SFC OBS ARE INDC AREAS OF LOW CLOUDS AND FOG ACROSS THE COASTAL WATERS AND IN THE VALLEYS. THE 10Z MODIS IMAGERY IS INDC THAT THE DEPTH OF THE FOG/LOW CLOUDS IS LESS THAN 1000 FEET. A SHORTWAVE IN THE GULF OF ALASKA...WEST OF THE QUEEN CHARLOTTE ISLANDS...WILL MOVE INTO THE PACIFIC NORTHWEST TODAY...AND THEN DIVE SOUTHEAST INTO THE ROCKIES TONIGHT. THE MAIN EFFECT FOR THE DISTRICT WILL BE SLIGHTLY COOLER TEMPS...MAINLY INLAND. WEAK RIDGING WILL KEEP THE DISTRICT DRY RIGHT THROUGH MONDAY ALONG WITH PLEASANT TEMPERATURES. MUCH NEEDED RAIN WILL RETURN TO THE DISTRICT TUESDAY AS A SYSTEM NORTH OF THE HAWAIIAN ISLANDS MOVES TO THE COAST. THE ASSOCIATED COLD FRONT WILL BRING RAIN TO THE DISTRICT BY TUESDAY AFTN...WITH RAIN LIKELY TUESDAY NIGHT. BOTH THE ECMWF AND THE GFS WEAKEN THE SYSTEM AS IT MOVES TO THE COAST...SO WHEREAS RAIN IS LIKELY RAINFALL AMOUNTS WILL NOT BE IMPRESSIVE...GENERALLY LESS THAN ONE HALF INCH. RAIN WILL BECOME SHOWERY BY WEDNESDAY MORNING AS THE UPPER TROUGH MOVES ONTO THE COAST. ALL SHOWER ACTIVITY WILL END WEDNESDAY EVENING...IF NOT SOONER AS THE MEDIUM RANGE MODELS MOVE THIS SYSTEM FAIRLY QUICKLY OUT OF THE AREA. AS HAS BEEN THE COMMON REFRAIN SINCE THE BEGINNING OF THE YEAR RIDGING WILL BUILD RIGHT BACK ALONG THE COAST. THIS WILL RESULT IN DRY WEATHER FOR THE END OF THE WEEK AND INTO NEXT WEEKEND WITH TEMPERATURES WARMING TO ABOVE NORMAL. MOS GUIDANCE IS HINTING AT TEMPS REACHING THE MID 70S IN THE INLAND VALLEYS NEXT SATURDAY... WITH 80S POSSIBLE IN INTERIOR MONTEREY AND SAN BENITO COUNTIES. && .AVIATION...AS OF 6:56 AM PDT SATURDAY...LOW CLOUDS HAVE MOVED IN OVER THE SAN FRANCISCO BAY AND MONTEREY BAY AREA AFFECTING LOCAL TERMINALS. THE LAYER REMAINS SHALLOW THEREFORE CIGS ARE NOT ANTICIPATED TO LINGER TOO LONG. IFR CIGS AROUND 500 FEET ARE EXPECTED TO BURN OFF AROUND 17Z-18Z THIS MORNING. LIGHT WINDS WILL PERSIST THROUGH THE MORNING THEN STRENGTHEN THIS AFTERNOON. HIGH CONFIDENCE. VICINITY OF KSFO...IFR CIGS WILL BURN OFF AROUND 17Z-18Z THIS MORNING. VFR CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE DAY. LIGHT WINDS WILL PERSIST THROUGH THE MORNING WITH SUSTAINED WINDS AROUND 15 KT AND GUSTS TO 25 KT ANTICIPATED THIS AFTERNOON. HIGH CONFIDENCE. KSFO BRIDGE APPROACH...SIMILAR TO KSFO MONTEREY BAY AREA TERMINALS...IFR CIGS WILL BURN OFF AROUND 17Z THIS MORNING. VFR CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE DAY. LIGHT WINDS WILL PERSIST THROUGH THE MORNING WITH SUSTAINED WINDS OF 10 TO 15 KT AND GUSTS TO 20 KT ANTICIPATED THIS AFTERNOON. HIGH CONFIDENCE. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT REYES TO PIGEON PT 0-10 NM SCA...PIGEON PT TO PT PINOS 0-10 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...PT ARENA TO PT REYES 0-10 NM SCA...PT ARENA TO PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM SCA...SF BAY FROM 2 PM SCA...MRY BAY FROM 2 PM && $$ PUBLIC FORECAST: STROBIN AVIATION/MARINE: CW VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA  FXUS66 KMTR 241154 AFDMTR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 454 AM PDT SUN MAR 24 2013 .DISCUSSION...AS OF 4:45 AM PDT SUNDAY...AS WAS MENTIONED IN LAST EVENINGS DISCUSSION WINDS HAVE DECREASED...AND WITH LESS MIXING IN THE BOUNDARY LAYER DEW PTS ARE HIGHER THIS MORNING. OTHER THAN A FEW HIGH CLOUDS STREAMING OVERHEAD SKIES ARE FOR THE MOST PART MOSTLY CLEAR. THERE IS A LITTLE PATCHY FOG...WITH HALF MOON BAY BEING THE USUAL CULPRIT ALONG WITH NAPA. THE LOW CLOUDS ARE VERY SHALLOW...WITH THE 10Z MODIS IMAGERY INDC THE TOP OF THE STRATUS BETWEEN 500-600 FEET. OFF TO THE BIGGER PICTURE...WATER VAPOR IMAGERY IS SHOWING A WELL DEFINED UPPER LOW NEAR 37/145...WITH THE GOES HIGH DENSITY WINDS INDC THAT THE RIDGE IS CENTERED NEAR 130W. TODAY LOOKS LIKE ANOTHER NICE DAY WITH MILD/WARM TEMPERATURES. THE RIDGE WILL WEAKEN ON MONDAY AS THE UPPER LOW MOVES INTO SOUTHERN OREGON. THIS WILL TURN THE FLOW ONSHORE...BRINGING COOLER TEMPS. THE UPPER LOW WILL BE WEAKENING AS IT MOVES TO THE COAST SO ALL RAIN WILL STAY TO THE NORTH OF THE DISTRICT. HAVE MENTIONED A CHANCE/SLIGHT CHANCE OF SHOWERS FOR THE DISTRICT FROM TUESDAY NIGHT THROUGH THURSDAY NIGHT AS A SERIES OF WEAK SYSTEMS MOVE INTO THE PACIFIC NORTHWEST. ANY RAIN THAT DOES FALL WILL BE LIGHT. THE PATTERN DOES LOOK TO BE WETTER FOR THE END OF THE WEEK AND INTO NEXT WEEKEND AS A STRONGER UPPER LOW DROPS SOUTHEAST OUT OF THE GULF OF ALASKA. THE ECMWF AND GFS DIFFER ON THE SPEED OF THE UPPER LOW...WITH THE GFS BRINGING IT TO THE CENTRAL CALIFORNIA COAST SATURDAY AFTN AND THE ECMWF ON SUNDAY MORNING. CUT OFF ,LOWS ARE NOTORIOUSLY DIFFICULT TO FORECAST...HOWEVER WITH THE GFS AND ECMWF HAVING SIMILAR SOLUTIONS IT APPEARS THAT NEXT WEEKEND... ESPECIALLY SATURDAY...COULD BE WET. IF FUTURE MODEL RUNS CONTINUE TO SHOW SIMILAR SOLUTIONS POPS WILL NEED TO BE BUMPED UP. ANY RAIN WE GET WILL BE VERY WELCOME. && .AVIATION...AS OF 10:45 PM PDT SATURDAY...A STRONG NORTHERLY PRESSURE GRADIENT WILL CONTINUE TO KEEP VFR CONDITIONS THROUGH THE PERIOD. VICINITY OF KSFO...VFR. KSFO BRIDGE APPROACH...VFR. MONTEREY BAY AREA TERMINALS...VFR. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 8 AM SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 8 AM && $$ PUBLIC FORECAST: STROBIN AVIATION/MARINE: CANEPA VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA  FXUS66 KMTR 241620 AFDMTR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 920 AM PDT SUN MAR 24 2013 .DISCUSSION...AS OF 9:00 AM PDT SUNDAY...MOSTLY CLEAR SKIES WITH LIGHT AND VARIABLE WINDS WERE PRESENT ACROSS THE REGION THIS MORNING...AS AN UPPER LEVEL RIDGE AXIS MOVE EAST TOWARD THE REGION. TEMPERATURES OVERNIGHT FELL INTO THE UPPER 30S TO MID 40S...SIMILAR TO THOSE OBSERVED LAST NIGHT. SOME OF THE COOLEST SPOTS...IN THE NORTH BAY AND SOUTHERN MONTEREY AND SAN BENITO COUNTIES...FELL INTO THE MID TO LOW 30S. UPPER LEVEL HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE AREA TODAY...WITH THE RIDGE AXIS JUST OFFSHORE BY THIS AFTERNOON. TEMPERATURES THROUGH THE REGION ARE FORECAST TO WARM A FEW DEGREES INLAND COMPARED TO YESTERDAY AFTERNOON...WITH READINGS IN THE 60S ALONG THE COAST...TO THE UPPER 60S TO MID 70S INLAND. THE ONE EXCEPTION WILL BE SOUTHERN MONTEREY COUNTY...WHERE 850 MB ARE FORECAST TO RISE TO AROUND 12 DEGREES C...LEADING TO SURFACE TEMPERATURES NEAR 80 DEGREES! CURRENT FORECAST LOOKS RIGHT ON TRACK WITH THE MAIN FOCUS ON THE POTENTIAL FOR RAIN MIDWEEK AND THE MORE PROMISING STORM SYSTEM NEXT WEEKEND. .PREVIOUS DISCUSSION...AS OF 4:45 AM PDT SUNDAY...AS WAS MENTIONED IN LAST EVENINGS DISCUSSION WINDS HAVE DECREASED...AND WITH LESS MIXING IN THE BOUNDARY LAYER DEW PTS ARE HIGHER THIS MORNING. OTHER THAN A FEW HIGH CLOUDS STREAMING OVERHEAD SKIES ARE FOR THE MOST PART MOSTLY CLEAR. THERE IS A LITTLE PATCHY FOG...WITH HALF MOON BAY BEING THE USUAL CULPRIT ALONG WITH NAPA. THE LOW CLOUDS ARE VERY SHALLOW...WITH THE 10Z MODIS IMAGERY INDC THE TOP OF THE STRATUS BETWEEN 500-600 FEET. OFF TO THE BIGGER PICTURE...WATER VAPOR IMAGERY IS SHOWING A WELL DEFINED UPPER LOW NEAR 37/145...WITH THE GOES HIGH DENSITY WINDS INDC THAT THE RIDGE IS CENTERED NEAR 130W. TODAY LOOKS LIKE ANOTHER NICE DAY WITH MILD/WARM TEMPERATURES. THE RIDGE WILL WEAKEN ON MONDAY AS THE UPPER LOW MOVES INTO SOUTHERN OREGON. THIS WILL TURN THE FLOW ONSHORE...BRINGING COOLER TEMPS. THE UPPER LOW WILL BE WEAKENING AS IT MOVES TO THE COAST SO ALL RAIN WILL STAY TO THE NORTH OF THE DISTRICT. HAVE MENTIONED A CHANCE/SLIGHT CHANCE OF SHOWERS FOR THE DISTRICT FROM TUESDAY NIGHT THROUGH THURSDAY NIGHT AS A SERIES OF WEAK SYSTEMS MOVE INTO THE PACIFIC NORTHWEST. ANY RAIN THAT DOES FALL WILL BE LIGHT. THE PATTERN DOES LOOK TO BE WETTER FOR THE END OF THE WEEK AND INTO NEXT WEEKEND AS A STRONGER UPPER LOW DROPS SOUTHEAST OUT OF THE GULF OF ALASKA. THE ECMWF AND GFS DIFFER ON THE SPEED OF THE UPPER LOW...WITH THE GFS BRINGING IT TO THE CENTRAL CALIFORNIA COAST SATURDAY AFTN AND THE ECMWF ON SUNDAY MORNING. CUT OFF ,LOWS ARE NOTORIOUSLY DIFFICULT TO FORECAST...HOWEVER WITH THE GFS AND ECMWF HAVING SIMILAR SOLUTIONS IT APPEARS THAT NEXT WEEKEND... ESPECIALLY SATURDAY...COULD BE WET. IF FUTURE MODEL RUNS CONTINUE TO SHOW SIMILAR SOLUTIONS POPS WILL NEED TO BE BUMPED UP. ANY RAIN WE GET WILL BE VERY WELCOME. && .AVIATION...AS OF 5:10 AM PDT SUNDAY...HIGH PROBABILITY VFR WILL CONTINUE THROUGH THE MORNING/DAY. THE ACV-SFO GRADIENT IS 4 MB AND SLOWLY WEAKENING. ONSHORE GRADIENTS ARE WEAK BUT WILL PICK UP A LITTLE THIS AFTERNOON/EVE AND AGAIN MONDAY AFTERNOON/EVE PER THE LATEST NAM MODEL...WITH SFO-SAC PREDICTED TO BE 3 MB EACH DAY. AREA DEWPOINTS HAVE BEEN SLOWLY INCREASING AND ADDITIONAL INCREASES ARE EXPECTED AREA-WIDE TONIGHT AS A VERY WEAK AND DRY TROUGH EMBEDDED WITHIN THE RIDGE MOVES ACROSS THE BAY AREA AND CENTRAL COAST. LOW LEVEL THICKNESS COOLING TONIGHT WILL LIKELY ASSIST WITH COASTAL STRATUS/FOG REDEVELOPMENT WITH WEAK-MODERATE ONSHORE BREEZES BRINGING IN SOME STRATUS/FOG INLAND LATE TONIGHT AND MONDAY MORNING. VICINITY OF KSFO...VFR. WEST WINDS GUSTING TO 20-25 KTS 23Z-04Z AS LOCAL ONSHORE GRADIENTS PICK UP A LITTLE. MVFR STRATUS CIG POSSIBLE BY 16Z MONDAY. KSFO BRIDGE APPROACH...VFR. AREAS MVFR CIGS POSSIBLY DEVELOPING BY MONDAY MORNING. MONTEREY BAY AREA TERMINALS...VFR TODAY. IFR POSSIBLY DEVELOPING 03Z-07Z TONIGHT WITH IFR LATE TONIGHT AND MONDAY MORNING. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...NONE. $$ PUBLIC FORECAST: RILEY/STROBIN AVIATION/MARINE: CANEPA VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA  FXUS66 KMTR 021126 AFDMTR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 426 AM PDT SUN JUN 2 2013 .DISCUSSION...AS OF 3:31 AM PDT SUNDAY...COOLING TREND IS UNDERWAY WITH STRATUS RETURNING TO THE COAST AND NOW STARTING TO PUSH A FEW MILES INLAND. STILL A ROBUST 8.5 MB NORTHERLY GRADIENT BUT THE ONSHORE IS 3.1 MB FROM SFO-SAC. WATER VAPOR IMAGERY SHOWS SEVERAL WEAK SHORTWAVES ROTATING DOWN THE COAST BETWEEN SAN FRANCISCO AND 130W. NAM MODEL VORTICITY AND 500 MB HEIGHT FIELDS DEPICT THESE FIELDS AS WELL WHICH WILL ACT TO ENHANCE THE ONSHORE FLOW AND MARINE LAYER DEPTH. THIS IS ALREADY STARTING TO SHOW UP ON THE FORT ORD PROFILER AND SAN CARLOS SODAR WITH THE INVERSION LAYER INCREASING TO AROUND 1500 FEET. TEMPERATURES WONT COOL TOO MUCH ALONG THE IMMEDIATE COAST WITH THE MOST DRAMATIC COOLING ABOUT 10-20 MILES INLAND. THEN TONIGHT THE MARINE LAYER SHOULD FURTHER DEEPEN WITH LOW CLOUDS AND FOG SPREADING WELL INLAND BY MONDAY MORNING. THEREFORE THE FAR INLAND VALLEYS WILL FEEL COOLING ON MONDAY AS PLACES LIKE CONCORD AND LIVERMORE STRUGGLE TO REACH 80 AFTER A WEEKEND OF TEMPS IN THE 90S. THE SYNOPTIC PATTERN WILL FEATURE A WEAK 500 MB CIRCULATION OFF THE CENTRAL COAST AT LEAST THROUGH WEDS OR POSSIBLY INTO THURSDAY. THIS SHOULD RESULT IN A FAIRLY TYPICAL EARLY SUMMER PATTERN OF EXTENSIVE NIGHT AND MORNING LOW CLOUDS FOLLOWED BY SUNNY AFTERNOONS. TEMPERATURES WILL RUN IN THE 60S COAST...70S INSIDE THE BAY AND 80S INLAND. BIG WEATHER STORY WILL THEN ONCE AGAIN TURN TO WARMING TREND BY FRIDAY. MODEL RUNS ARE PRETTY CONSISTENT IN BUILDING A 590-593 DM HIGH OVER MOST OF NORTHERN AND CENTRAL CALIFORNIA FRIDAY AND SATURDAY. 850 MB TEMPS TEMPS ARE PROGGED TO GET PRETTY OUT OF HAND FROM 25-30 CELSIUS NEXT WEEKEND. THE RIDGE WILL BUILD RIGHT OVER HEAD SO GRADIENTS BECOME NEUTRAL BUT WITH THE RIDGE SO STRONG THE HEAT SHOULD BUILD PRETTY CLOSE TO THE COAST. STILL ALMOST A WEEK OUT SO WILL HOLD OFF ON ANY OUTLOOKS BUT AS CONFIDENCE GROWS WILL NEED TO CONSIDER POSSIBLE HEAT HEADLINES. && .AVIATION...AS OF 4:24 AM PDT SUNDAY...COMPARE TO 24 HOURS AGO...WIDESPREAD STRATUS BLANKETS THE COASTLINE. SODARS/PROFILERS PUT THE INVERSION AROUND 1000-1500 FEET LATEST MODIS- VIIRS IMAGERY ACTUALLY SHOWS A FINGER OF STRATUS SLIDING THROUGH THE GAP JUST NORTH OF KSFO. FARTHER SOUTH...STRATUS HAS MADE IT INTO MONTEREY MORE EASILY. THAT BEING SAID...TOUGH CALL FOR SF BAY REGARDING STRATUS THIS MORNING. WILL ALLOW FOR POSS CIGS DURING THE MORNING HOURS THEN CLEARING THIS AFTERNOON. MRY BAY CIGS THROUGH THE EARLY AFTERNOON THEN POSSIBLE CLEARING. CIGS RETURN EVERYWHERE TONIGHT WITH A BETTER DEFINED MARINE LAYER. VICINITY OF KSFO...PREVAILING CONDITIONS THIS MORNING WILL BE VFR...BUT HAVE INTRODUCED A TEMPO GROUP THROUGH 16Z FOR CIGS UNDER 1K FEET. VFR CIGS THIS AFTERNOON WITH GUSTY ONSHORE FLOW. CIGS RETURN TONIGHT. KSFO BRIDGE APPROACH...AS OF NOW IT APPEAR THAT CIGS WILL BE MORE LIKELY AROUND SFO. A FEW CIGS MAY IMPACT NORTH END OF APPROACH. MONTEREY BAY AREA TERMINALS...IFR/LIFR CONDITIONS AROUND MONTEREY BAY THIS MORNING. CIGS WILL LINGER THROUGH THE EARLY AFTERNOON. A FEW HOURS OF VFR CONDITIONS THIS AFTERNOON BEFORE CIGS RETURN EARLY TONIGHT. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT REYES TO PIGEON PT 0-10 NM SCA...PIGEON PT TO PT PINOS 0-10 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM GLW...PT ARENA TO PIGEON PT 10-60 NM SCA...PT ARENA TO PT REYES 0-10 NM FROM 3 PM GLW...PT ARENA TO PT REYES 0-10 NM UNTIL 3 PM SCA...SF BAY FROM NOON SCA...MRY BAY FROM NOON && $$ PUBLIC FORECAST: RWW AVIATION/MARINE: MM VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA  FXUS66 KMTR 061127 AFDMTR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 427 AM PDT SUN APR 6 2014 .SYNOPSIS...MUCH ABOVE NORMAL DAYTIME TEMPERATURES ARE FORECAST FROM SUNDAY THROUGH TUESDAY AS HIGH PRESSURE BUILDS OVER CALIFORNIA. TEMPERATURES WILL PEAK ON MONDAY AND TUESDAY. A COOLING TREND WILL BEGIN WEDNESDAY AS WEAK LOW PRESSURE APPROACHES THE COAST. THIS SYSTEM WILL MOVE INTO SOUTHERN CALIFORNIA LATE IN THE WEEK...AND IS ONLY EXPECTED TO BRING SOME CLOUDS AND COOLER WEATHER TO THE AREA. THUS...IT LOOKS LIKE A CONTINUATION OF DRY WEATHER THROUGH THE END OF NEXT WEEK AND INTO NEXT WEEKEND. && .DISCUSSION...AS OF 3:00 AM PDT SUNDAY...WATER VAPOR SATELLITE IMAGERY SHOWS AN UPPER RIDGE CENTERED OFFSHORE ALONG 130W...BUILDING SLOWLY EASTWARD OVER CALIFORNIA. SUBSIDENCE UNDER THIS RIDGE IS WARMING THE AIRMASS ALOFT AND GENERATING GREATER LOW LEVEL STABILITY. THE RESULT IS DEVELOPMENT OF PATCHY LOW CLOUDS ALONG THE COAST...MAINLY ALONG THE SAN MATEO COUNTY COAST. EXPECT LOW CLOUDS TO BECOME SOMEWHAT MORE WIDESPREAD BY DAYBREAK. BUT LOW CLOUDS AND PATCHY FOG ARE EXPECTED TO CLEAR RELATIVELY EARLY THIS MORNING AS THE FLOW JUST ABOVE THE SURFACE VEERS MORE TO THE NORTH AND BEGINS TO ADVECT A DRIER AIRMASS ACROSS THE REGION. THIS WARMER AND DRIER AIRMASS WILL MEAN HIGH TEMPERATURES TODAY WILL BE SEVERAL DEGREES ABOVE NORMAL WITH PLENTY OF AFTERNOON SUN...EVEN AT THE OCEAN. THE WARMING TREND WILL CONTINUE INTO MONDAY AS THE UPPER RIDGE AXIS SHIFTS DIRECTLY OVER CALIFORNIA AND LOW LEVEL FLOW CONTINUES OUT OF THE NORTH. BY MONDAY...HIGH TEMPERATURES ARE FORECAST TO CLIMB WELL INTO THE 70S NEAR THE COAST AND INTO THE 80S INLAND. THE WARMING TREND WILL CONTINUE INLAND ON TUESDAY WHEN 850 MB TEMPERATURES ARE FORECAST TO PEAK AT CLOSE TO 18 DEG C ACROSS THE SOUTHERN PART OF OUR AREA. HIGHS IN THE LOWER 90S ARE LIKELY BY TUESDAY ACROSS PORTIONS OF INTERIOR MONTEREY COUNTY AND SAN BENITO COUNTY. COASTAL TEMPERATURES ARE A MORE DIFFICULT TO PREDICT ON TUESDAY AS LOW LEVEL FLOW GRADUALLY TURNS TO THE SOUTH. COASTAL TEMPS LIKELY WON'T WARM ANY FURTHER ON TUESDAY...BUT WILL STILL REMAIN WELL ABOVE NORMAL. ALTHOUGH TEMPERATURES ARE FORECAST TO BE WELL ABOVE NORMAL EARLY THIS WEEK...RECORD HIGHS ARE NOT ALL THAT LIKELY (SEE RECORD HIGHS IN CLIMATE SECTION BELOW). THE UPPER RIDGE AXIS WILL HAVE MOVED WELL OFF TO OUR EAST BY MIDWEEK AND A CUTOFF LOW WILL BEGIN TO APPROACH THE SOUTH-CENTRAL CALIFORNIA COAST. THESE DEVELOPMENTS WILL TRIGGER A RETURN TO ONSHORE FLOW BY WEDNESDAY AND A COOLING TREND DURING THE SECOND HALF OF THE WEEK. COOLING ON WEDNESDAY WILL MOSTLY BE NEAR THE COAST AND IN THE COASTAL VALLEYS...WITH COOLER AIR THEN SPREADING FARTHER INLAND BY THURSDAY. THE MODELS AGREE THAT THE UPPER LOW WILL LOSE MOST OF ITS MOISTURE BY THE TIME IT REACHES THE SOUTHERN CA COAST LATE IN THE WEEK. THUS...THERE APPEARS LITTLE CHANCE OF PRECIPITATION IN OUR AREA. SO WILL CONTINUE TO LEAVE THE FORECAST DRY THROUGH THE NEXT SEVEN DAYS. && .AVIATION...AS OF 4:15 AM PDT SUNDAY...MAJOR OVERHAUL TO FORECAST PACKAGE. WENT MORE OPTIMISTIC WITH VFR CONDITIONS AT ALL TERMINALS. LATEST SPORT MODIS/VIIRS SATELLITE IMAGERY SHOWS THAT STRATUS REMAINS OFF THE COAST WITH LITTLE MOVEMENT INLAND. LATEST HRRR MODEL GUIDANCE ALSO KEEPS STRATUS OUT OF SAN FRANCISCO BAY. VFR TONIGHT AS WELL. CONF IS MED-HIGH. VICINITY OF KSFO...VFR. GUSTY ONSHORE LATER THIS AFTERNOON. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...VFR. && .MARINE AND BEACH...AS OF 4:17 AM PDT SUNDAY...THE MUCH TALKED ABOUT LONG PERIOD SWELL IS TAKING ITS TIME ARRIVING ON THE CENTRAL COAST. HOWEVER...LATEST BUOY REPORTS TO THE N ARE STARTING TO PICK UP ON THE 17-18 SECOND PERIOD. ONCE THE LONGER PERIOD MOVES IN LATER THIS MORNING...IT WILL NOT BE LARGE BUT WILL BE FAST MOVING AND CAPABLE OF WASHING PEOPLE FROM BEACHES AND FISHERMEN FROM ROCKS AND JETTIES IN THE FORM OF SNEAKER WAVES. THEREFORE A BEACH HAZARD STATEMENT REMAINS IN EFFECT FOR THE ENTIRE COAST SUNDAY MORNING THROUGH SUNDAY EVENING. && .CLIMATE...RECORD HIGH TEMPERATURES FOR APRIL 6TH THROUGH 8TH. AT FIRST GLANCE IT APPEARS THAT 1989 FEATURED A MULTI-DAY HEAT SPELL. SF BAY AREA .LOCATION................APRIL 6TH APRIL 7TH APRIL 8TH KENTFIELD...............94/1924 91/1989 91/1989 SAN RAFAEL..............87/1989 88/1989 91/1989 NAPA....................91/1939 89/1989 91/1989 SAN FRANCISCO...........91/1989 92/1989 94/1989 SFO AIRPORT.............89/1989 89/1989 92/1989 OAKLAND (DOWNTOWN)......86/1989 87/1989 88/1989 RICHMOND................89/1989 90/1989 93/1989 LIVERMORE...............89/1939 89/1989 90/1989 SAN JOSE................93/1989 93/1989 94/1989 GILROY..................91/1989 94/1989 96/1989 MONTEREY BAY AREA .LOCATION...............APRIL 6TH APRIL 7TH APRIL 8TH MONTEREY...............90/1989 92/1989 92/1989 SANTA CRUZ.............93/1989 94/1989 90/1989 SALINAS................97/1989 98/1989 78/1980 SALINAS AIRPORT........97/1989 98/1989 95/1989 KING CITY..............98/1989 98/1989 100/1989 && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM SCA...PT ARENA TO PT REYES 0-10 NM SCA...PT ARENA TO PT REYES 10-60 NM SCA...PT REYES TO PIGEON PT 10-60 NM SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 9 AM && $$ PUBLIC FORECAST: DYKEMA AVIATION: MM MARINE: MM CLIMATE: RWW VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA  FXUS66 KMTR 031555 AFDMTR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 855 AM PDT SUN MAY 3 2015 .SYNOPSIS...A RELATIVELY DEEP MARINE LAYER AND PERSISTENT ONSHORE FLOW WILL MAINTAIN AREAS OF NIGHT AND MORNING LOW CLOUDS THROUGH THE MIDDLE OF THE WEEK...ALONG WITH TEMPERATURES NEAR TO SLIGHTLY BELOW NORMAL. AN UPPER LEVEL LOW IS THEN FORECAST TO DEVELOP OVER CALIFORNIA BY THURSDAY. THIS LOW WILL MIX OUT THE MARINE LAYER...BUT ALSO MAINTAIN RELATIVELY COOL WEATHER CONDITIONS INTO THE SECOND HALF OF THE WEEK. THERE IS ALSO A SLIGHT CHANCE OF SHOWERS WITH THIS WEATHER SYSTEM...MAINLY ACROSS THE SOUTHERN PORTION OF OUR AREA FROM LATE THURSDAY NIGHT THROUGH FRIDAY. && .DISCUSSION...AS OF 08:41 AM PDT SUNDAY...DEEP MARINE LAYER THIS MORNING IS SLIGHTLY OVER 2000 FEET AT FORD ORD. LAST NIGHTS MODIS AND EARLY MORNING GOES IMAGERY SHOWS CLOUD THICKNESS AROUND 1000 FEET...DEEPER SOUTH OF THE BAY AREA AND SHALLOWER NORTH BAY. IMPLICATION IS FOR EARLIER DISSIPATION NORTH BAY AND INLAND...BUT STRENGTH OF ONSHORE FLOW SHOULD KEEP COASTAL AREAS IN THE STRATUS MUCH OF THE DAY. CURRENT FORECAST LOOKS ON TRACK WITH MORNING TEMPERATURES IN THE 50S CLIMBING TO THE 60S ALONG THE COAST TO 70S INLAND THIS AFTERNOON. ONSHORE FLOW TO CONTINUE NEXT FEW DAYS WITH EXTENSIVE PUSH OF STRATUS INLAND NIGHTS AND MORNINGS. LATEST NAM STRENGTHENS ONSHORE GRADIENT TO 3.7 MB SFO TO SAC MONDAY AFTERNOON. MONDAY MAY ACTUALLY BE THE COOLEST DAY OF THE NEXT SEVERAL...THEN MARINE LAYER MIXING INCREASES TOWARD MIDWEEK WITH UPPER LEVEL TROFING DEVELOPING ALONG THE COAST AND COASTAL TEMPERATURES MAY WARM SLIGHTLY. && .PREV DISCUSSION...AS OF 3:10 AM PDT SUNDAY...THE COOLING TREND THAT BEGAN ON FRIDAY WILL CONTINUE TODAY...ALTHOUGH THE MAGNITUDE OF TODAY'S COOLING IS EXPECTED TO BE LESS THAN WHAT OCCURRED DURING THE PAST TWO DAYS. A WEAK UPPER TROUGH CURRENTLY OFF THE WEST COAST IS FORECAST TO SHIFT EASTWARD OVER THE CA COAST BY MONDAY MORNING. BOTH THE NAM AND WRF MODELS INDICATE THIS WILL RESULT IN AN EVEN GREATER INLAND SURGE OF MARINE LAYER CLOUDS TONIGHT...AS WELL AS CONTINUED COOL CONDITIONS INTO MONDAY. AFTER THE WEAK UPPER TROUGH MOVES INLAND ON MONDAY...SURFACE HIGH PRESSURE WILL STRENGTHEN OFF THE NORTHERN CA COAST...RESULTING IN INCREASING NORTHWEST WINDS ALONG THE COAST ON MONDAY NIGHT AND TUESDAY. THESE WINDS SHOULD PRODUCE SUFFICIENT MIXING TO CLEAR OUT MUCH OF THE LOW CLOUDINESS BY TUESDAY AFTERNOON AND THUS BRING ABOUT SLIGHT WARMING ON TUESDAY. AN UPPER LOW IS FORECAST TO DEVELOP OVER THE PAC NW BY MIDWEEK. THE GFS AND ECMWF AGREE REASONABLY WELL IN DROPPING THAT LOW DUE SOUTH ACROSS NORTHERN AND CENTRAL CALIFORNIA FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...AND THEN EJECTING THAT LOW EASTWARD ON FRIDAY. BOTH MODELS ALSO FORECAST SCATTERED LIGHT PRECIPITATION ACROSS PORTIONS OF OUR AREA FROM THURSDAY AFTERNOON THROUGH LATE FRIDAY...WITH THE MOST WIDESPREAD SHOWER ACTIVITY PROJECTED TO OCCUR ACROSS THE SOUTHERN PART OF OUR AREA LATE THURSDAY NIGHT AND FRIDAY MORNING AS SHORTWAVE ROTATES INLAND OVER THE CENTRAL COAST. THE AIRMASS OVER OUR AREA WILL COOL SEVERAL DEGREES FROM LATE WEDNESDAY INTO THURSDAY AS THE UPPER LOW DROPS IN FROM THE NORTH. THIS COOLING WILL BE SUFFICIENT TO MIX OUT THE MARINE LAYER ACROSS THE NORTHERN PART OF OUR AREA BY LATE WEDNESDAY AND IN ALL AREAS BY THURSDAY. TEMPERATURES WILL COOL BELOW NORMAL IN ALL AREAS BY THURSDAY AND REMAIN COOL THROUGH THE END OF THE WEEK. THE UPPER LOW IS FORECAST TO MOVE WELL OFF TO OUR EAST BY LATE FRIDAY...AND SHORTWAVE RIDGING IS EXPECTED TO PRODUCE DRY AND SLIGHTLY WARMER WEATHER NEXT WEEKEND. BUT THE LONGER RANGE MODELS MAINTAIN AN UNSETTLED PATTERN...WITH ANOTHER WEAK WEATHER SYSTEM PROJECTED TO APPROACH CALIFORNIA EARLY NEXT WEEK. && .AVIATION...AS OF 4:36 AM PDT SUNDAY...AS NOTED ABOVE DEEP MARINE LAYER IN PLACE WITH WIDESPREAD MVFR CIGS WITH A FEW POCKETS OF IFR CONDITIONS. KSJC AND KLVK ARE ON THE EDGE AND LATEST TRENDS SUGGEST STRATUS AROUND SUNRISE. BASED ON LATEST GUIDANCE CLEARING WILL BE MID MORNING FOR MANY LOCATIONS WITH VFR THIS AFTERNOON. CIGS RETURN AGAIN TONIGHT. CONF IS MEDIUM-HIGH. VICINITY OF KSFO...MVFR CIGS WITH CLEARING 17-18Z. BRIEF PERIOD OF NE WINDS POSSIBLE. STRONGER WEST PUSH OF WINDS THIS AFTERNOON. SFO BRIDGE APPROACH...SIMILAR TO SFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH 18Z. VFR THIS AFTERNOON. && .BEACHES...AS OF 4:36 AM PDT SUNDAY...NO REAL CHANGE FROM PREVIOUS FORECAST. A SERIES OF LONG PERIOD SOUTHERLY SWELLS WILL IMPACT THE CENTRAL COAST TODAY. PT CONCEPTION BUOY IS ALREADY SHOWING 3.5 FT AT 25 SECONDS. ALTHOUGH THE WAVE HEIGHTS ASSOCIATED WITH THESE LONG PERIOD WAVES WILL BE RELATIVELY SMALL...4 TO 6 FEET...THE POWERFUL NATURE OF LONG PERIOD WAVES WILL RESULT IN EXCEPTIONALLY STRONG RIP CURRENTS ALONG THE COAST ESPECIALLY ON SOUTHERLY FACING BEACHES SUCH AS STINSON BEACH IN MARIN COUNTY AND THE BEACHES ALONG THE MONTEREY BAY COAST OF SANTA CRUZ COUNTY. ADDITIONALLY...THESE LONG PERIOD WAVES WILL ALSO RESULT IN LARGE SHORE BREAK AT TWIN LAKES STATE BEACH AND THE SANTA CRUZ BOARDWALK BEACH. LARGE SHORE BREAK CAN RESULT IN NECK AND BACK INJURIES. IF YOU PLAN ON ENTERING THE WATER PLEASE DO SO NEAR A LIFEGUARD AND ALWAYS KEEP AN EYE ON THE OCEAN WHEN VISITING THE BEACH. && .MARINE...AS OF 04:31 AM PDT SUNDAY...GUSTY NORTHERLY WINDS WILL CONTINUE OVER THE NORTHERN OUTER WATERS THROUGH EARLY NEXT WEEK. ELSEWHERE...SOUTHERLY FLOW WILL CONTINUE TODAY. NORTHERLY FLOW WILL DEVELOP OVER MOST OF THE COASTAL WATERS TONIGHT AND MONDAY AS HIGH PRESSURE BUILDS OVER THE REGION. A LONG PERIOD SOUTHERLY SWELL WILL IMPACT THE COASTAL WATERS SUNDAY AND CONTINUE THROUGH TUESDAY. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 3 PM && $$ PUBLIC FORECAST: KBB AVIATION/MARINE: MM VISIT US AT WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA WWW.YOUTUBE.COM/NWSBAYAREA  FXUS66 KMTR 232158 AFDMTR Area Forecast Discussion National Weather Service San Francisco Bay Area 158 PM PST Fri Feb 23 2018 .SYNOPSIS...Mostly sunny skies will prevail around the Bay Area today. Another very cool night is forecast for Friday night. Dry weather and slightly warmer temperatures are expected over the weekend. Cooler, unsettled weather is expected to return by early next week with another system bringing rain to the area later next week. && .DISCUSSION...as of 01:58 PM PST Friday...Abundant sunshine blankets the Bay Area this afternoon and most of the state for that matter. Despite the afternoon sunshine temperatures are still running several degrees below normal. Max temps will likely top in the lower to mid 50s for most locations. The higher peaks in the region a much colder: Diablo low 30s, Mt Hamilton and Chews Ridge mid-upper 20s. Afternoon MODIS imagery still shows some lingering snow over the higher peaks in Monterey/San Benito Counties. For tonight, clear skies will continue leading to another cold night, especially away from the coast and major urban centers. Lows tonight will be in the 20s to lower 30s across the interior and inland valleys. Closer to the coast and major urban centers will be mid 30s to lower 40s. Needless to say some frost will be possible. Dry weekend ahead as the Bay Area remains in a cold dry northwest flow. There is a slight uptick in 500 mb heights and 850 mb temps, especially on Sunday, leading to a slight warming trend. That being said, temperatures will still be below normal for this time of year, but interior locations may crack 60 degs by Sunday. Overnight lows will still be cold and frost will be possible again Saturday night. Want to at least mention that embedded in the long wave trough a weak short-wave trough slides through NE California on Saturday afternoon/evening. Moisture seems limited to NE of the Bay Area. Therefore, will not include any precip at this time. Latest model guidance continues to bring another re-enforcing upper trough late Sunday into Monday. Better dynamics and better moisture will allow for an increased chance of precip. Current forecast will bring showers into the North Bay early Monday and then spread southward through the day and even into early Tuesday. Rainfall amounts will generally be a few hundredths to a few tenths over the higher peaks. Snow levels will initially be 2,500 feet and above and then gradually drop through the day. Similar to the last few system minor snow accumulations will be possible with the Santa Lucias receiving the most. Brief break Tuesday into Wednesday with a short-wave ridge. If the long are right, and they have been showing this solution for several runs now, late next week could be interesting. Deterministic and ensembles means bring one of the more "robust" storm system into CA as of late. Lots of details will need to be sorted out between now and then, but timing looks to be right at the end of the month. Stay Tuned... && .AVIATION...as of 9:40 AM PST Friday...for 18Z TAFs. VFR conditions through the period with mainly clear skies. Winds west to northwest at 10 to 20 kt in the afternoon. Vicinity of KSFO...VFR conditions are expected to prevail with mainly clear skies. West to northwest winds 10 to 20 kt before decreasing in the evening. SFO Bridge Approach...Similar to KSFO. Monterey Bay Terminals...VFR through the period with mainly clear skies. Possibly FEW to SCT low clouds tonight into tomorrow morning. Onshore winds this afternoon. && .MARINE...as of 08:15 AM PST Friday...Gale-force northerly winds over the outer waters will subside later this morning. High pressure over the eastern Pacific will continue to produce moderate to strong winds over the coastal waters into the weekend. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...SCA...Pigeon Pt to Pt Pinos 0-10 nm until 10 PM SCA...Pt Arena to Pigeon Pt 10-60 nm SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm until 9 PM SCA...Pt Arena to Pt Reyes 0-10 nm SCA...Pt Reyes to Pigeon Pt 0-10 nm && $$ PUBLIC FORECAST: MM AVIATION: AS MARINE: AS Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/nwsbayarea www.twitter.com/nwsbayarea www.youtube.com/nwsbayarea