FXUS66 KMTR 301151 AFDMTR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 451 AM PDT TUE APR 30 2013 ...A WARM WEEK AHEAD WITH WINDY CONDITIONS IN THE NORTH AND EAST BAY HILLS THIS EVENING THROUGH WEDNESDAY MORNING... ...RED FLAG WARNINGS ISSUED FOR THE NORTH AND EAST BAY HILLS FROM 6 PM TODAY THROUGH 6 PM WEDS... .DISCUSSION...AS OF 3:20 AM PDT TUESDAY...SATELLITE AND SURFACE OBS INDICATE ONLY SOME MINOR POCKETS OF LOW CLOUDS AND PATCHY FOG. RIGHT NOW HALF MOON BAY IS THE ONLY SPOT REPORTING REDUCED VISIBILITIES WHILE MONTEREY NOW HAS A CEILING. DETAILS FROM THE OVERNIGHT SATELLITE FOG PRODUCT ARE A BIT DIFFICULT TO MAKE OUT ALTHOUGH LOOKS LIKE THE AREAS ARE VERY SMALL IN NATURE. NORTHERLY SURFACE FLOW REMAINS AROUND 10 MB WHICH WILL HELP TO GREATLY LIMIT IMPACTS TO ALMOST ALL SPOTS. BOTTOM LINE...OUTSIDE OF JUST A FEW SPOTS...SHOULD BE A MOSTLY SUNNY DAY ACROSS OUR AREA. HIGHS YESTERDAY WERE ABOVE NORMAL IN ALMOST ALL LOCATIONS AND APPROACHED RECORD VALUES IN A FEW AREAS. TODAY SHOULD BE A BIT COOLER AS HEIGHTS AND TEMPERATURES ALOFT DROP IN RESPONSE TO A SHORTWAVE TROF THAT WILL DROP SOUTHWARD FROM CANADA INTO THE NORTHERN ROCKIES. MOST LOCATIONS WILL LOWER 5 DEGREES OR SO COMPARED TO MONDAY -- STILL WARM BUT WELL SHORT OF ALMOST ALL RECORDS. COASTAL AREAS SHOULD SEE MORE OF A MARINE INFLUENCE AS THE WESTERLY GRADIENT WILL BE BETWEEN 1 AND 2 MB FOR MOST OF THE DAY. HIGHS WILL RANGE FROM 60S TO LOWER 70S AT THE COAST TO MID 70S TO MID 80S INLAND. WINDS WILL INCREASE BY LATE THIS AFTERNOON AS A RIDGE OF HIGH PRESSURE AT THE SURFACE BUILDS IN TO OUR NORTH WHICH WILL LEAD TO THE NORTHERLY PRESSURE GRADIENT TO GREATLY INCREASE. BY TONIGHT THE SFO-WMC FORECAST CALLS FOR AN IMPRESSIVE 21 MB WHILE 925 MB SPEEDS ARE EXPECTED TO BE AS STRONG AS 45 KT. WIND ADVISORY REMAINS IN PLACE GOING INTO WEDNESDAY AS GUSTS OVER 50 MPH LOOK LIKELY FOR BOTH THE NORTH AND EAST BAY HILLS. SHOULD BE NOTED THAT ALTHOUGH THE GUIDANCE IS CONCENTRATING MORE ON THE NORTH BAY HILLS...GROUND TRUTH FROM PAST EVENTS SHOWS THAT MANY TIMES THE EAST BAY HILLS SEE WINDS AS STRONG (OR LOCALLY STRONGER). MAIN CONCERN REMAINS FOR POTENTIAL FIRE WEATHER ISSUES, SO THE RED FLAG WARNING WILL CONTINUE. A GENERIC WIND ADVISORY ALSO REMAINS IN PLACES FOR LOCAL GUSTS OF 50 TO 60 MPH. TEMPERATURES WILL INCREASE AGAIN FOR WEDNESDAY THROUGH FRIDAY AS THE RIDGE OF HIGH PRESSURE OUT IN THE PACIFIC BUILDS ACROSS OUR AREA. THERE IS A POTENTIAL WE COULD SEE A FAIR NUMBER OF RECORDS FALLING ON FRIDAY WHEN THE WARMEST AIR ARRIVES (AND MANY RECORD SHOW A SLIGHT DIP FOR THAT DAY). STANDARD DEVIATIONS OF NEARLY 6 ARE FORECAST FOR TEMPERATURES AT 1000 MB WHICH -- IF IT VERIFIES -- WOULD CAUSE A SLEW OF RECORDS TO BE TOPPLED. STILL SOME UNCERTAINTY IF THE WARMTH WILL EXTEND ALL OF THE WAY TO THE COAST OR ENOUGH OF A FLOW OFF THE WATER WILL KEEP THINGS THERE MORE MODERATED. INTERIOR SPOTS DEFINITELY LOOK VERY WARM TO HOT WITH 850 MB READINGS OF 19-21C POSSIBLE. TEMPERATURES WILL COOL BY THE WEEKEND AND INTO NEXT WEEK AS AN UPPER LEVEL LOW MOVES NEAR OUR AREA. 850 MB TEMPS WILL DROP BY AT LEAST 5C AND 500 MB HEIGHTS WILL LOWER FROM 585 DM TO JUST 560 DM. HIGHS AT THE SURFACE WILL BE IN THE 60S AT THE COAST WILL 70S TO LOWER 80S INLAND ON SUNDAY WITH A FEW ADDITIONAL DEGREES OF COOLING LIKELY FOR NEXT WORK WEEK. && .AVIATION...AS OF 4:50 AM PDT TUESDAY...VFR EXCEPT PATCHY MVFR AROUND MRY BAY THROUGH MID MORNING. FT ORD PROFILER SHOWS MARINE LAYER CLIMBING UP TO 1500 FT HOWEVER NORTH SOUTH SFO-ACV GRADIENT REMAINS OVER 9 MB PREVENTING FURTHER STRATUS INTRUSION. VICINITY OF KSFO...VFR THROUGH THE PERIOD. WEST WINDS INCREASING TO 20 TO 25 KT THIS AFTERNOON. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...SHORT LIVED MVFR THIS MORNING. VIIRS DAY NIGHT SATELLITE AND GOES-R MVFR PROBABILITIES INDICATE CLOUD DECK IS PATCHY. OTHERWISE VFR WITH ONSHORE WINDS. && .FIRE WEATHER...AS OF 3:20 AM TUESDAY...RED FLAG WARNINGS CONTINUE FOR THE NORTH AND EAST BAY HILLS ZONES ABOVE 1000 FEET FROM 6 PM TODAY THROUGH 6 PM WEDNESDAY. ALL OF THE WEATHER FACTORS LINE UP FOR A STRONG RED FLAG EVENT. WILD CARD HAS BEEN THE FUELS WHICH ALL RECENT READINGS SHOW BEING AT OR NEAR RECORD DRY LEVELS FOR LATE APRIL. RED FLAGS IN LATE APRIL OR EARLY MAY ARE ESSENTIALLY UNPRECEDENTED AROUND HERE. HOWEVER WE'VE HAD VERY DRY WEATHER SINCE JANUARY FIRST WITH ABOVE NORMAL TEMPERATURES THE LAST FEW WEEKS IN GENERAL. TEMPERATURES SHOULD COOL A FEW DEGREES TODAY COMPARED TO MONDAY BUT STILL BE ABOVE NORMAL INLAND. A DRY COOL FRONT WILL PASS TO OUR NORTH AND EAST AND INDUCE A VERY STRONG PRESSURE GRADIENT...SIMILAR TO A FALL OFFSHORE WIND EVENT. HOWEVER UNLIKE THE LATE FALL OR WINTER THIS EVENT WILL BE VERY WARM TO HOT. EXPECT MILD TO WARM OVERNIGHT READINGS IN THE HILLS TONIGHT INTO WEDNESDAY WITH HUMIDITY STAYING UNDER 30 PERCENT AND LIKELY AROUND 20 PERCENT. NAM MODEL HAS BEEN VERY CONSISTENT IN SHOWING A SPIKE IN WINDS AT THE 1500-3000 FOOT LEVEL AROUND 06Z (11 PM TUESDAY NIGHT). A SEVERAL HOUR PERIOD OF SUSTAINED NORTHEAST WINDS FROM 20 TO 35 MPH WITH FREQUENT GUSTS TO 50 MPH AND STRONGER GUSTS TO 60 MPH WILL BE STRONG ENOUGH TO BRING DOWN POWER LINES AS WELL AS DROUGHT/DISEASED STRESSED TREES. OBVIOUSLY THE DOWNED LINES COULD SPARK NEW FIRES. HOPING THE RED FLAG WILL INDUCE EXTRA VIGILANCE WITH THE GENERAL PUBLIC FOR THINGS LIKE BARBECUES...WELDING AND SPRING BURNING PROJECTS. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...WIND ADVISORY...NORTH AND EAST BAY HILLS 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 GLW...PT ARENA TO PIGEON PT 10-60 NM SCA...PT ARENA TO PT REYES 0-10 NM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM && $$ PUBLIC FORECAST: BELL AVIATION/MARINE: AC FIRE WEATHER: BELL/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 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 281203 AFDMTR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 503 AM PDT FRI JUN 28 2013 ...HOT INLAND TODAY THROUGH EARLY NEXT WEEK... .DISCUSSION...AS OF 4:27 AM PDT FRIDAY...FORECAST ITEM OF INTEREST FOR THE NEXT SEVERAL DAYS WILL BE PROLONGED PERIOD OF HOT TEMPERATURES INLAND. SIMILAR TO THE EVENT EARLIER THIS MONTH THE MICRO-CLIMATES WILL KICK INTO GEAR WITH HUGE TEMPERATURE DIFFERENCE FROM THE COAST TO THE INLAND VALLEYS. THE CURRENT 24 HOUR TEMPERATURE CHANGES ARE DRAMATIC WITH VALLEY LOCATIONS ABOUT 4-8 DEGREES WARMER THAN YESTERDAY MORNING. HOWEVER THE HILL LOCATIONS ARE RUNNING AS MUCH AS 15 DEGREES WARMER WITH 80 DEGREE READINGS ALREADY SHOWING UP IN THE NORTH AND EAST BAY HILLS. WITH THE LONG DAYS TEMPERATURES WILL SKY ROCKET AS THE SUN COMES UP THIS MORNING. THE FORT ORD PROFILER SHOWS THE FOG DECK IS VERY SHALLOW AT AROUND 200 FEET. SO EVEN THOUGH THE OCEAN IS COVERED IN A SHALLOW CLOUD/FOG DECK THERE WILL BE LITTLE OR NO INLAND MOVEMENT THIS MORNING. THUS EVEN WITH ONSHORE GRADIENTS ALL SIGNS POINT TO ANOTHER SUNNY AND HOT DAY ONCE YOU GET AWAY FROM THE COAST AND OUTSIDE THE BAY. GIVEN THE MUCH WARMER START IN THE HILLS EXPECT TO SEE AN OVERALL WARMING TREND OF 5-10 DEGREES FOR MOST INLAND LOCATIONS. WE HAVE A HEAT ADVISORY STARTING AT 11 AM SATURDAY AND CONTINUING THROUGH SUNDAY EVENING FOR THE INLAND VALLEYS AND HILLS. PART OF THIS IS BASED ON THE CUMULATIVE EFFECTS OF SEVERAL DAYS OF ABOVE NORMAL TEMPERATURES. BASED ON INTER-OFFICE AND PARTNER COORDINATION SEE NO NEED TO MAKE ANY CHANGES TO THE ADVISORY RIGHT NOW. A DISTINCT POSSIBILITY THAT IT WOULD BE EXTENDED FOR ANOTHER DAY BUT GIVEN ITS STILL FRIDAY WE'VE GOT TIME TO IRON OUT THOSE DETAILS. ONLY ZONE THAT COULD ARGUABLY BE ADDED WOULD BE OUR SANTA CRUZ MOUNTAIN ZONE THAT WILL LIKELY NOW SEE SEVERAL DAYS OF MILD OVERNIGHT LOWS (CURRENTLY 75 IN BEN LOMOND) FOLLOWED BY HOT DAYS WELL INTO THE 90S. OVERALL IT LOOKS LIKE WE'LL GET CLOSE TO SOME RECORD HIGHS OVER THE WEEKEND BUT NOT A SLAM DUNK THAT RECORDS WILL BE BROKEN. UPSHOT IS THAT CURRENT FORECASTS AND PRODUCTS SEEM TO HAVE WEEKEND COVERED PRETTY WELL. NEXT FORECAST CHALLENGE WILL BE TO PREDICT THE ONSET OF THE COOLING TREND. IT LOOKS LIKE HOT WEATHER WILL CONTINUE INLAND AT LEAST THROUGH MONDAY OR TUESDAY OF NEXT WEEK. HOWEVER THE ECMWF IS STARTING TO SHOW THE INFLUENCE OF THE TROUGH OFFSHORE GETTING CLOSER TO THE COAST BY LATER MONDAY OR TUESDAY SO COASTAL AND BAYSIDE COOLING WILL OCCUR EARLY IN THE WEEK. PRETTY STRONG CONSENSUS IN ALL MODELS SHOWING MORE PRONOUNCED INLAND COOLING BY WEDS AND THURSDAY AS THE RIDGE BREAKS DOWN. WILL NEED TO MONITOR FOR POSSIBLE ELEVATED CONVECTION INTRUSION BUT RIGHT NOW NOT SEEING ANY FOCUSED OVER OUR CWA. && .AVIATION...AS OF 5:00 AM PDT FRIDAY...VFR CONDITIONS PREVAIL AT ALL TERMINALS THIS MORNING. A VERY SHALLOW MARINE LAYER EXISTS PER FT ORD PROFILER AND KHAF METARS...APPROX 400 FEET. OVERNIGHT VIIRS SATELLITE IMAGERY DOES SHOW PATCHY STRATUS STRETCHING FROM NEAR THE GOLDEN GATE SOUTH TO THE MONTEREY BAY. HOWEVER...NOT MUCH INLAND PENETRATION WITH THIS STRATUS. ONSHORE GRADIENT IS ABOUT 1.5 MB AS WELL. THAT BEING SAID...DOWNPLAYED STRATUS CHANCES IN SAN FRANCISCO BAY AND MONTEREY BAY. ONSHORE GRADIENT INCREASES THIS AFTERNOON WITH SEA BREEZE. VICINITY OF KSFO...WILL FORECAST VFR CONDITIONS THROUGH THE PERIOD. GUSTY WINDS POSSIBLE AGAIN THIS AFTERNOON. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...CURRENT FORECAST IS FOR MAINLY VFR CONDITIONS. HOWEVER...SATELLITE DOES SHOW SOME PATCHY CLOUDS AROUND THE MONTEREY PENINSULA. A LOOK OUTSIDE ALSO REVEALED CLEAR SKIES OVER MRY TERMINAL. INCLUDED A TEMPO FOR MRY TO A ALLOW FOR A BRIEF CIG. && .CLIMATE...RECORD HIGHS THIS WEEKEND SITE JUNE 29 JUNE 30 --------------------------------------------------------------------- SANTA ROSA 103 IN 1934 103 IN 1972 KENTFIELD 105 IN 1934 106 IN 1972 SAN RAFAEL 99 IN 1956 98 IN 1999 NAPA 104 IN 1934 105 IN 1972 SAN FRANCISCO 95 IN 1934 93 IN 1996 KSFO 87 IN 1959 92 IN 1996 OAKLAND MUSEUM 81 IN 1999 90 IN 1972 OAKLAND AIRPORT 91 IN 1950 90 IN 1950 RICHMOND 95 IN 1985 91 IN 1996 LIVERMORE 107 IN 1934 112 IN 1972 MOUNTAIN VIEW 91 IN 1950 92 IN 1996 SAN JOSE 102 IN 1934 100 IN 1996 GILROY 105 IN 1976 98 IN 1999 MONTEREY 80 IN 1996 89 IN 1996 SANTA CRUZ 102 IN 1934 98 IN 1996 SALINAS 87 IN 1996 94 IN 1996 KING CITY 110 IN 1925 109 IN 1950 && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 3 PM SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 3 PM SCA...PT ARENA TO PT REYES 0-10 NM FROM 9 AM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM && $$ 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 141143 AFDMTR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 443 AM PDT FRI MAR 14 2014 .SYNOPSIS...AFTER A BIT OF COOLING TODAY...A WARM AND DRY UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BUILD STRONGLY INTO THE WEST COAST OVER THE WEEKEND. THIS WILL RESULT IN AFTERNOON TEMPERATURES REACHING WELL ABOVE SEASONAL NORMS...AND POSSIBLY TO NEAR RECORD LEVELS FOR THESE DATES. THIS WARM-UP WILL BE SHORT-LIVED HOWEVER...WITH INCREASED ONSHORE FLOW AND A SIGNIFICANTLY COOLER AIR MASS MOVING IN ALOFT THE FIRST PART OF NEXT WEEK. DRY CONDITIONS ARE EXPECTED TO CONTINUE THROUGH MID WEEK...BUT THEN WITH UPPER LEVEL TROUGHING AND A CHANCE OF RAIN FOR THE OUTER PORTION OF THE FORECAST PERIOD. && .DISCUSSION...AS OF 4:10 AM PDT FRIDAY...THE DRY TAIL END OF A WEATHER SYSTEM MOVING IN TO THE PACIFIC NORTHWEST IS APPROACHING OUR DISTRICT...AND RESULTING IN ENHANCEMENT OF THE MARINE LAYER AND A RETURN OF THE MARINE STRATUS. LATEST GOES FOG PRODUCT IMAGERY...AND IN RATHER SPECTACULAR DETAIL JUST REC'D SUOMI VIIRS NIGHTTIME HIGH RES VISUAL IMAGE...SHOW COVERAGE ALONG MUCH OF THE COAST FROM PT REYES SOUTH TO THE VICINITY OF THE MONTEREY PENINSULA...AND A BROAD SWATH EXTENDING INLAND ACROSS SAN FRANCISCO AND THROUGH THE GOLDEN GATE TO THE EAST BAY. LATEST BODEGA BAY AND FT ORD PROFILER DATA INDICATE A MARINE LAYER DEPTH OF ABOUT 1300 FT. SOME THIN HIGH CLOUDS ARE ALSO PASSING THROUGH ABOVE. NAM MODEL AND IN-HOUSE LOCAL WRF MODEL BOUNDARY LAYER RH OUTPUT BOTH INDICATE STRATUS SHOULD GENERALLY CLEAR BY MIDDAY...EXCEPT ALONG THE SAN MATEO COAST AND IN THE VICINITY OF THE MONTEREY PENINSULA. EXPECT AFTERNOON HIGHS TO BE AROUND 3 TO 5 DEGS COOLER THAN ON THURSDAY...BUT STILL WELL ABOVE SEASONAL NORMS ESPECIALLY INLAND. THEN BEGINNING FRIDAY NIGHT AND CONTINUING THROUGH THE WEEKEND...MODELS ARE IN EXCELLENT AGREEMENT THAT AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BUILD STRONGLY INLAND THROUGH NORTHERN AND CENTRAL CALIFORNIA...WITH WARMING OF TEMPS ALOFT AND LOW-LEVEL FLOW TURNING OFFSHORE...ALBEIT RATHER WEAKLY. THE NET RESULT FOR US WILL BE CLEAR SKIES AND SIGNIFICANTLY WARMER DAYTIME TEMPS...ESP AWAY FROM THE COAST. THAT SAID...MODEL TREND OVER THE PAST FEW DAYS HAS BEEN MILDLY IN THE DIRECTION OF NOT QUITE AS MUCH WARMING ALOFT AND A BIT LESS BY WAY OF OFFSHORE FLOW. ECMWF OUTPUT FROM A FEW DAYS AGO WAS PROJECTING 850 MB TEMPS OVER THE HEART OF THE BAY AREA WOULD REACH UP TO 16C AT THE HEIGHT OF THE UPPER-LEVEL WARMING...BUT NOW CONFINED TO THE 14C TO 14.5C RANGE. AND SIMILARLY WITH SURFACE TROUGHING SHIFTED JUST A BIT MORE INLAND...AND SO A BIT LESS BY WAY OF OFFSHORE ORIENTED FLOW. DOESN'T CHANGE THE BASIC PICTURE THAT DAYTIME MAX TEMPS WILL REACH TO WELL-ABOVE SEASONAL NORMAL LEVELS...ESPECIALLY INLAND...BUT CHANCES OF GETTING UP TO RECORD LEVELS HAS DIMINSHED A BIT. ALSO NOT AS MUCH OF A WARM-UP NEAR THE COAST AS HAD BEEN THINKING A COUPLE OF DAYS AGO. IN THE SUNDAY EVENING TIME FRAME...MODELS PROJECT THE UPPER LEVEL RIDGE WILL RAPIDLY WEAKEN AND SHIFT INLAND AS ANOTHER...AND A BIT STRONGER...WEATHER SYSTEM RAPIDLY APPROACHES AND MOVES IN TO THE PACIFIC NW. AGAIN NO PRECIP IS EXPECTED IN OUR AREA...BUT IT WILL RESULT IN BOTH SIGNIFICANT COOLING OF THE AIR MASS ALOFT AND A QUICK RETURN TO MODERATELY STRONG ONSHORE FLOW. COASTAL STRATUS LOOKS TO RAPIDLY REDEVELOP SUNDAY EVENING...AND DAYTIME TEMPS ON MONDAY WILL COOL SIGNIFICANTLY...THOUGH STILL GENERALLY REMAIN SEVERAL DEGS ABOVE SEASONAL NORMS. FOR DOWNTOWN SAN FRANCISCO FOR EXAMPLE...PRESENT FORECAST CALLS FOR A HIGH OF 72 ON SUNDAY COOLING TO 67 ON MONDAY...BUT THAT'S STILL 5 DEGS ABOVE THE SEASONAL NORM FOR THE DATE OF 62. THEREAFTER NOT A GREAT DEAL OF CHANGE IS EXPECTED THROUGH ABOUT MIDWEEK...BUT THEN RAIN CHANCES RETURN TO AT LEAST MORE NORTHERN PORTIONS OF OUR DISTRICT AS LARGER-SCALE UPPER LEVEL TROUGHING DEVELOPS ALONG THE WEST COAST AND RESULTS IN THE STORM TRACK SHIFTING A BIT SOUTHWARD. WE'LL STILL BE ON THE SOUTHERN END OF THE DISTURBANCES MOVING THROUGH...BUT CLOSE ENOUGH THAT WE COULD SEE SOME PRECIP. && .AVIATION...AS OF 10:57 PM PDT THURSDAY...FOR 06Z TAFS. SKIES REMAIN MOSTLY CLEAR INLAND WITH SOME PATCHY STRATUS NOW DEVELOPING ALONG THE SAN MATEO COAST AND AROUND THE MONTEREY PENINSULA. MOST LIKELY AIRPORT TO GET CIGS WILL BE MONTEREY BUT FAIRLY STRONG WINDS OVER THE OCEAN MAY KEEP STRATUS SOMEWHAT TRANSIENT. CANT COMPLETELY RULE OUT A SUNRISE SURPRISE FOR KSFO BUT ANY MORNING CIGS SHOULD BE SHORT LIVED. VICINITY OF KSFO...VFR FORECAST WITH CLEAR SKIES OVERNIGHT. SOME CONCERN WITH THE PATCHY STRATUS ALONG THE COAST BUT INVERSION DEPTH SUGGESTS NO CIGS. WILL CONTINUE TO MONITOR BUT FEEL THAT SHOULD ANY STRATUS PUSH THROUGH THE GAP IT WOULD BE FICKLE AND BURN EARLY...BEFORE 16Z. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...LOW CLOUDS NOW FORMING OVER MONTEREY PENINSULA AND KMRY WILL LIKELY GET SOME PERIODS OF CIGS AT OR BELOW 1000 FEET OVERNIGHT. STILL FAIRLY HIGH CONFIDENCE THAT ANY CIGS WILL BURN QUICKLY IN THE MORNING AND WILL SHOW SUCH IN TAF. && .CLIMATE...RECORD HIGH TEMPERATURES FOR MARCH 15-16 ALONG WITH THE MOST RECENT DATE IT OCCURRED. SF BAY AREA .LOCATION................ SAT 15 SUN 16 KENTFIELD............... 85/2004 86/2004 SAN RAFAEL.............. 83/1972 87/1972 NAPA.................... 86/2004 88/2004 SAN FRANCISCO........... 82/2004 85/1914 SFO AIRPORT............. 81/2004 82/2004 OAKLAND (DOWNTOWN)...... 85/2004 85/2004 OAKLAND AIRPORT......... 83/2004 83/2004 RICHMOND................ 85/2004 84/1972 LIVERMORE............... 83/1972 88/1972 MOFFETT FIELD........... 83/2004 84/2004 SAN JOSE................ 84/2004 85/2004 GILROY.................. 84/1994 85/2004 MONTEREY BAY AREA .LOCATION................ SAT 15 SUN 16 MONTEREY................ 81/2004 84/1978 SANTA CRUZ.............. 83/1926 86/1914 SALINAS................. 85/1972 87/2004 SALINAS AIRPORT......... 83/1972 87/2004 KING CITY............... 90/2007 91/2007 && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 1 PM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...PT ARENA TO PT REYES 10-60 NM SCA...PT REYES TO PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PINOS 10-60 NM FROM 1 PM SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM FROM 1 PM SCA...PT ARENA TO PT REYES 0-10 NM SCA...PT REYES TO PIGEON PT 0-10 NM FROM 9 AM && $$ PUBLIC FORECAST: BLIER AVIATION: RWW MARINE: RWW CLIMATE: SA/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 141520 AFDMTR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 820 AM PDT FRI MAR 14 2014 .SYNOPSIS...DRY WEATHER CAN BE EXPECTED THROUGH THE MIDDLE OF NEXT WEEK. LOOK FOR TEMPERATURES TO WARM OVER THE WEEKEND -- POSSIBLY TO RECORD BREAKING LEVELS. SOME COOLING CAN BE EXPECTED NEXT WEEK AS THE ONSHORE FLOW RETURNS. && .DISCUSSION...AS OF 8:20 AM PDT FRIDAY...CLEARING FORECAST ACROSS OUR AREA LATER THIS MORNING WILL LEAD TO MOSTLY SUNNY CONDITIONS ALONG WITH TEMPERATURES CONTINUING TO RUN ABOVE NORMAL. BIGGER STORY WILL BE OVER THE WEEKEND WITH THE RIDGE AXIS OVERHEAD PLUS WARMEST 850 MB READINGS. THOSE WILL COMBINE WITH AN OFFSHORE FLOW AT THE SURFACE TO PRODUCE VERY WARM READINGS FOR THIS TIME OF YEAR. WOULD DEFINITELY EXPECT A FEW RECORDS TO FALL. CURRENT FORECAST LOOKS ON TRACK -- WILL JUST DO AN UPDATE AS THE CLOUDS BREAK THIS MORNING. .PREVIOUS DISCUSSION...THE DRY TAIL END OF A WEATHER SYSTEM MOVING IN TO THE PACIFIC NORTHWEST IS APPROACHING OUR DISTRICT...AND RESULTING IN ENHANCEMENT OF THE MARINE LAYER AND A RETURN OF THE MARINE STRATUS. LATEST GOES FOG PRODUCT IMAGERY...AND IN RATHER SPECTACULAR DETAIL JUST REC'D SUOMI VIIRS NIGHTTIME HIGH RES VISUAL IMAGE...SHOW COVERAGE ALONG MUCH OF THE COAST FROM PT REYES SOUTH TO THE VICINITY OF THE MONTEREY PENINSULA...AND A BROAD SWATH EXTENDING INLAND ACROSS SAN FRANCISCO AND THROUGH THE GOLDEN GATE TO THE EAST BAY. LATEST BODEGA BAY AND FT ORD PROFILER DATA INDICATE A MARINE LAYER DEPTH OF ABOUT 1300 FT. SOME THIN HIGH CLOUDS ARE ALSO PASSING THROUGH ABOVE. NAM MODEL AND IN-HOUSE LOCAL WRF MODEL BOUNDARY LAYER RH OUTPUT BOTH INDICATE STRATUS SHOULD GENERALLY CLEAR BY MIDDAY...EXCEPT ALONG THE SAN MATEO COAST AND IN THE VICINITY OF THE MONTEREY PENINSULA. EXPECT AFTERNOON HIGHS TO BE AROUND 3 TO 5 DEGS COOLER THAN ON THURSDAY...BUT STILL WELL ABOVE SEASONAL NORMS ESPECIALLY INLAND. THEN BEGINNING FRIDAY NIGHT AND CONTINUING THROUGH THE WEEKEND...MODELS ARE IN EXCELLENT AGREEMENT THAT AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BUILD STRONGLY INLAND THROUGH NORTHERN AND CENTRAL CALIFORNIA...WITH WARMING OF TEMPS ALOFT AND LOW-LEVEL FLOW TURNING OFFSHORE...ALBEIT RATHER WEAKLY. THE NET RESULT FOR US WILL BE CLEAR SKIES AND SIGNIFICANTLY WARMER DAYTIME TEMPS...ESP AWAY FROM THE COAST. THAT SAID...MODEL TREND OVER THE PAST FEW DAYS HAS BEEN MILDLY IN THE DIRECTION OF NOT QUITE AS MUCH WARMING ALOFT AND A BIT LESS BY WAY OF OFFSHORE FLOW. ECMWF OUTPUT FROM A FEW DAYS AGO WAS PROJECTING 850 MB TEMPS OVER THE HEART OF THE BAY AREA WOULD REACH UP TO 16C AT THE HEIGHT OF THE UPPER-LEVEL WARMING...BUT NOW CONFINED TO THE 14C TO 14.5C RANGE. AND SIMILARLY WITH SURFACE TROUGHING SHIFTED JUST A BIT MORE INLAND...AND SO A BIT LESS BY WAY OF OFFSHORE ORIENTED FLOW. DOESN'T CHANGE THE BASIC PICTURE THAT DAYTIME MAX TEMPS WILL REACH TO WELL-ABOVE SEASONAL NORMAL LEVELS...ESPECIALLY INLAND...BUT CHANCES OF GETTING UP TO RECORD LEVELS HAS DIMINISHED A BIT. ALSO NOT AS MUCH OF A WARM-UP NEAR THE COAST AS HAD BEEN THINKING A COUPLE OF DAYS AGO. IN THE SUNDAY EVENING TIME FRAME...MODELS PROJECT THE UPPER LEVEL RIDGE WILL RAPIDLY WEAKEN AND SHIFT INLAND AS ANOTHER...AND A BIT STRONGER...WEATHER SYSTEM RAPIDLY APPROACHES AND MOVES IN TO THE PACIFIC NW. AGAIN NO PRECIP IS EXPECTED IN OUR AREA...BUT IT WILL RESULT IN BOTH SIGNIFICANT COOLING OF THE AIR MASS ALOFT AND A QUICK RETURN TO MODERATELY STRONG ONSHORE FLOW. COASTAL STRATUS LOOKS TO RAPIDLY REDEVELOP SUNDAY EVENING...AND DAYTIME TEMPS ON MONDAY WILL COOL SIGNIFICANTLY...THOUGH STILL GENERALLY REMAIN SEVERAL DEGS ABOVE SEASONAL NORMS. FOR DOWNTOWN SAN FRANCISCO FOR EXAMPLE...PRESENT FORECAST CALLS FOR A HIGH OF 72 ON SUNDAY COOLING TO 67 ON MONDAY...BUT THAT'S STILL 5 DEGS ABOVE THE SEASONAL NORM FOR THE DATE OF 62. THEREAFTER NOT A GREAT DEAL OF CHANGE IS EXPECTED THROUGH ABOUT MIDWEEK...BUT THEN RAIN CHANCES RETURN TO AT LEAST MORE NORTHERN PORTIONS OF OUR DISTRICT AS LARGER-SCALE UPPER LEVEL TROUGHING DEVELOPS ALONG THE WEST COAST AND RESULTS IN THE STORM TRACK SHIFTING A BIT SOUTHWARD. WE'LL STILL BE ON THE SOUTHERN END OF THE DISTURBANCES MOVING THROUGH...BUT CLOSE ENOUGH THAT WE COULD SEE SOME PRECIP. && .AVIATION...AS OF 4:56 AM PDT FRIDAY...FOR 12Z TAFS. 1500 FOOT CLOUD DECK HAS SPREAD INTO SF BAY WITH LOWER CIGS ALONG THE COAST AND AROUND MONTEREY BAY. EVIDENCE SUGGESTS CLOUD LAYER NOT TOO THICK AND FAIRLY HIGH CONFIDENCE FOR CIGS BURNING OFF BY 1730Z. TAF WAS COMPOSED CONSERVATIVE AND WOULDN'T BE SURPRISED TO SEE CLEARING EARLIER...CLOSER TO 17Z. OTHERWISE WEST WINDS THIS AFTERNOON WITH NO IMPACT TO OPERATIONS. THE PATTERN CHANGES TONIGHT SO NOT CONVINCED WE'LL GET CIGS AGAIN TONIGHT INTO SATURDAY MORNING. VICINITY OF KSFO...1400-1500 FOOT STRATUS DECK OVER AIRPORT SHOULD MIX OUT PRETTY QUICKLY WITH ABOVE AVERAGE CONFIDENCE FOR VFR BY 1730Z. WEST WINDS THIS AFTERNOON WITH GUSTS TO 17 KT. KSFO BRIDGE APPROACH...SO FAR CIGS AREN'T SHOWING UP AT THE BRIDGE BUT WOULDN'T BE SURPRISED TO SEE MORE DEVELOPMENT CLOSE TO THE BRIDGE THROUGH 16Z...OR FOR CLOUDS TO IMPAIR VISUALS BETWEEN THE BRIDGE AND AIRPORT BUT CLEARING BY 16-17Z. MONTEREY BAY AREA TERMINALS...MVFR CIGS FOR MONTEREY BAY TERMINALS THROUGH 17Z...WITH SOME CONCERN THEY COULD LINGER LONGER FOR KMRY. IF ANYTHING WITH NW WINDS CLOUDS WILL BE JUST WEST OF THE AIRPORT FOR MUCH OF THE DAY. && .CLIMATE...RECORD HIGH TEMPERATURES FOR MARCH 15-16 ALONG WITH THE MOST RECENT DATE IT OCCURRED. SF BAY AREA .LOCATION................ SAT 15 SUN 16 KENTFIELD............... 85/2004 86/2004 SAN RAFAEL.............. 83/1972 87/1972 NAPA.................... 86/2004 88/2004 SAN FRANCISCO........... 82/2004 85/1914 SFO AIRPORT............. 81/2004 82/2004 OAKLAND (DOWNTOWN)...... 85/2004 85/2004 OAKLAND AIRPORT......... 83/2004 83/2004 RICHMOND................ 85/2004 84/1972 LIVERMORE............... 83/1972 88/1972 MOFFETT FIELD........... 83/2004 84/2004 SAN JOSE................ 84/2004 85/2004 GILROY.................. 84/1994 85/2004 MONTEREY BAY AREA .LOCATION................ SAT 15 SUN 16 MONTEREY................ 81/2004 84/1978 SANTA CRUZ.............. 83/1926 86/1914 SALINAS................. 85/1972 87/2004 SALINAS AIRPORT......... 83/1972 87/2004 KING CITY............... 90/2007 91/2007 && .MARINE...AS OF 5 AM FRIDAY...SMALL CRAFT ADVISORIES OVER THE OCEAN TODAY THROUGH EARLY SATURDAY FOR NW WINDS. NEXT CONCERN WILL BE BUILDING NW SWELL LATER SUNDAY. WAVE MODELS SHOWING SEAS UP TO 13 FEET WITH LONG PERIODS AROUND 18 SECONDS. WITH SUNNY AND WARM WEATHER FORECAST SUNDAY WILL HAVE TO CONSIDER A BEACH HAZARD STATEMENT ON SUNDAY FOR POSSIBLE RIPS IN FUTURE FORECAST UPDATES. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 1 PM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...PT ARENA TO PT REYES 10-60 NM SCA...PT REYES TO PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PINOS 10-60 NM FROM 1 PM SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM FROM 1 PM SCA...PT ARENA TO PT REYES 0-10 NM SCA...PT REYES TO PIGEON PT 0-10 NM FROM 9 AM && $$ PUBLIC FORECAST: BELL/BLIER AVIATION: RWW MARINE: RWW CLIMATE: SA/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 161129 AFDMTR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 429 AM PDT WED APR 16 2014 .SYNOPSIS...DRY CONDITIONS WILL CONTINUE THROUGH THE WEEKEND. PATCHY FOG AND CLOUDS NEAR THE COAST WILL BECOME MORE EXTENSIVE THURSDAY NIGHT AND FRIDAY AS A WEAK WEATHER SYSTEM MOVES ONSHORE. A STRONGER LOW PRESSURE SYSTEM WILL ARRIVE LATE MONDAY AND TUESDAY BRINGING A THREAT FOR SHOWERS...COOLER TEMPERATURES...AND GUSTY WINDS. && .DISCUSSION...AS OF 03:53 AM PDT WEDNESDAY...TONIGHTS VIIRS SATELLITE IMAGERY AROUND 230 AM SHOWED PATCHY LOW CLOUDS NEAR MONTEREY BAY AND SALINAS VALLEY. LATEST GOES FOG PRODUCT IMAGERY INDICATING STRATUS HAS BECOME A LITTLE MORE WIDESPREAD IN THE SALINAS VALLEY...NEAR HALF MOON BAY...AND MONTEREY BAY THE LAST COUPLE HOURS. BREEZY NORTHWEST WINDS OVER THE OPEN WATERS HAVE KEPT THE BOUNDARY LAYER WELL MIXED AND CONFINED STRATUS TO CONVERGENCE AND UPSLOPE AREAS NEAR THE COAST FAVORED BY NW WINDS. SHORT WAVE RIDGE WILL PROGRESS EASTWARD ACROSS THE STATE TODAY...KEEPING THE MARINE LAYER UNDER 1500 FEET. SURFACE PRESSURE GRADIENTS WILL REMAIN STRONG FROM THE NORTHWEST TO SOUTHEAST WITH SFO-ACV OVER 6 MB TODAY AND WINDS WILL REMAIN AT LEAST BREEZY OVER THE OPEN WATERS. HRRR MODEL SURFACE RH FIELD INDICATES LIMITED STRATUS AGAIN TODAY. AS THE RIDGE SHIFTS EASTWARD THE FLOW WILL BECOME MORE ONSHORE THURSDAY WITH A BETTER ESTABLISHED MARINE LAYER...SO EXPECT EXTENSIVE STRATUS TO RETURN TO COASTAL AREAS BY THURSDAY MORNING. A WEAK TROF IN ZONAL FLOW WILL APPROACH THE COAST THURSDAY NIGHT DEEPENING THE MARINE LAYER AND INCREASING ONSHORE FLOW. THIS TROF SPLITS OVER THE AREA FRIDAY...AND THE LACK OF UPPER LEVEL LIFT SHOULD KEEP CONDITIONS DRY. COOLER AIR ALOFT WITH 850 MB TEMPERATURES DROPPING TO 10 DEG C SHOULD DISRUPT THE MARINE LAYER FRIDAY BUT SPREAD COOLER AIR INLAND WITH CONTINUED ONSHORE FLOW. AFTER A BRIEF BREAK SATURDAY UNDER WEAK HIGH PRESSURE AND MOSTLY CLEAR SKIES...ANOTHER MINOR SYSTEM WILL BRUSH BY TO THE NORTH OF OUR AREA SUNDAY WITH MORE COASTAL CLOUDS. A STRONGER TROF WILL DROP OVER CALIFORNIA LATE MONDAY AND TUESDAY BRINGING A THREAT FOR SHOWERS AND MUCH COOLER CONDITIONS WITH GUSTY WINDS. FORECAST MODELS ARE CONSISTENTLY ADVERTISING THIS STRONGER SYSTEM...AND EVEN THOUGH THE SYSTEM LACKS A SIGNIFICANT MOISTURE TAP...COLD AIR ALOFT WILL BE PLENTIFUL AND SHOWERS ARE CERTAINLY POSSIBLE ESPECIALLY OVER THE MOUNTAINS. && .AVIATION...AS OF 10:50 PM PDT TUESDAY...SATELLITE IMAGERY SHOWS MOSTLY CLEAR SKIES OVER THE AREA EXCEPT FOR PATCHY STRATUS NEAR THE MONTEREY BAY. THE NORTH TO SOUTH SURFACE PRESSURE GRADIENT HAS RAMPED UP TO WELL OVER 6 MB FROM ACV TO SFO...THUS EXPECT LESS IN THE WAY OF STRATUS IMPACTS ACROSS THE BAY AREA TAF LOCATIONS TONIGHT. THERE COULD BE SOME CIGS OVER SAN JOSE AND OAKLAND LATE...AND STRATUS WILL IMPACT THE MONTEREY AND SALINAS TERMINALS OVERNIGHT. VICINITY OF KSFO...VFR IS EXPECTED TO PERSIST THROUGH THE FORECAST PERIOD WITH MVFR CONDITIONS DEVELOPING LATE TO THE EAST OF THE TERMINAL AND APPROACH. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS BECOMING LOCALLY IFR LATE. CLEARING EXPECTED BY 18Z WEDNESDAY WITH INCREASING NORTHWEST WINDS. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PIGEON PT TO PT PINOS 0-10 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM GLW...PT ARENA TO PT REYES 10-60 NM GLW...PT REYES TO PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PINOS 10-60 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM SCA...PT ARENA TO PT REYES 0-10 NM SCA...PT REYES TO PIGEON PT 0-10 NM SCA...MONTEREY BAY FROM 1 PM && $$ PUBLIC FORECAST: KBB AVIATION: SIMS 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 161530 AFDMTR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 830 AM PDT WED APR 16 2014 .SYNOPSIS...DRY CONDITIONS WILL CONTINUE THROUGH THE WEEKEND. PATCHY FOG AND CLOUDS NEAR THE COAST WILL BECOME MORE EXTENSIVE THURSDAY NIGHT AND FRIDAY AS A WEAK WEATHER SYSTEM MOVES ONSHORE. A STRONGER LOW PRESSURE SYSTEM WILL ARRIVE LATE MONDAY AND TUESDAY BRINGING A THREAT FOR SHOWERS...COLDER TEMPERATURES...AND GUSTY WINDS. && .DISCUSSION...AS OF 8:30 AM PDT WEDNESDAY...MINOR FORECAST UPDATE THIS MORNING WITH CLOUDS MOSTLY CONFINED AROUND MONTEREY BAY AND THROUGH THE SALINAS VALLEY. THE REASON? NORTHERLY SURFACE GRADIENT RAMPED UP TO OVER 7 MB OVERNIGHT HELPING TO PUSH THE STRATUS DECK TO THE SOUTH. MOSTLY SUNNY CONDITIONS ARE FORECAST FOR ALL AREA BY LATER THIS MORNING WITH WARM CONDITIONS INLAND -- UPPER 70S TO AROUND 90. AT THE COAST AN WEAK ONSHORE FLOW WILL CONTINUE WHICH WILL KEEP IT CLOSER TO THE 60S AND LOWER 70S. ONE EXCEPTION WILL BE FOR PARTS OF SANTA CRUZ WHERE THE NORTHERLY FLOW WILL DOWNSLOPE AND HELP TO PUSH HIGHS 75-80. QUIET WEATHER WILL CONTINUE THROUGH THE REST OF THE WEEK INTO MONDAY BEFORE A BIG CHANGE HITS US ON TUESDAY. GOOD MODEL AGREEMENT THAT A COLD SYSTEM WILL DROP DOWN TO OUR AREA HELPING TO DROP 700 MB TEMPS TO THE -9 TO -11C RANGE. MOISTURE AVAILABILITY IS THE ONE BIG QUESTION MARK, ALTHOUGH SOME SHOWERS SHOULD BE GENERATED. IF THE MODELS VERIFY SNOW LEVELS WILL DROP TO UNDER 4000 FEET AND INSTABILITY WILL GREATLY INCREASE LEADING TO SOME THUNDERSTORMS AS WELL. WINDS WILL ALSO BECOME GUSTY FROM THE NORTH. UNLESS THERE IS A HUGE CHANGE IN THE MODELS, TEMPS WILL BE LOWERED FOR TUESDAY INTO WEDNESDAY ESPECIALLY FOR THE HILLS. STILL NEARLY A WEEK OUT, BUT IT'S VERY INTERESTING FOR A LATE APRIL SYSTEM! .PREVIOUS DISCUSSION...TONIGHTS VIIRS SATELLITE IMAGERY AROUND 230 AM SHOWED PATCHY LOW CLOUDS NEAR MONTEREY BAY AND SALINAS VALLEY. LATEST GOES FOG PRODUCT IMAGERY INDICATING STRATUS HAS BECOME A LITTLE MORE WIDESPREAD IN THE SALINAS VALLEY...NEAR HALF MOON BAY...AND MONTEREY BAY THE LAST COUPLE HOURS. BREEZY NORTHWEST WINDS OVER THE OPEN WATERS HAVE KEPT THE BOUNDARY LAYER WELL MIXED AND CONFINED STRATUS TO CONVERGENCE AND UPSLOPE AREAS NEAR THE COAST FAVORED BY NW WINDS. SHORT WAVE RIDGE WILL PROGRESS EASTWARD ACROSS THE STATE TODAY...KEEPING THE MARINE LAYER UNDER 1500 FEET. SURFACE PRESSURE GRADIENTS WILL REMAIN STRONG FROM THE NORTHWEST TO SOUTHEAST WITH SFO-ACV OVER 6 MB TODAY AND WINDS WILL REMAIN AT LEAST BREEZY OVER THE OPEN WATERS. HRRR MODEL SURFACE RH FIELD INDICATES LIMITED STRATUS AGAIN TODAY. AS THE RIDGE SHIFTS EASTWARD THE FLOW WILL BECOME MORE ONSHORE THURSDAY WITH A BETTER ESTABLISHED MARINE LAYER...SO EXPECT EXTENSIVE STRATUS TO RETURN TO COASTAL AREAS BY THURSDAY MORNING. A WEAK TROF IN ZONAL FLOW WILL APPROACH THE COAST THURSDAY NIGHT DEEPENING THE MARINE LAYER AND INCREASING ONSHORE FLOW. THIS TROF SPLITS OVER THE AREA FRIDAY...AND THE LACK OF UPPER LEVEL LIFT SHOULD KEEP CONDITIONS DRY. COOLER AIR ALOFT WITH 850 MB TEMPERATURES DROPPING TO 10 DEG C SHOULD DISRUPT THE MARINE LAYER FRIDAY BUT SPREAD COOLER AIR INLAND WITH CONTINUED ONSHORE FLOW. AFTER A BRIEF BREAK SATURDAY UNDER WEAK HIGH PRESSURE AND MOSTLY CLEAR SKIES...ANOTHER MINOR SYSTEM WILL BRUSH BY TO THE NORTH OF OUR AREA SUNDAY WITH MORE COASTAL CLOUDS. A STRONGER TROF WILL DROP OVER CALIFORNIA LATE MONDAY AND TUESDAY BRINGING A THREAT FOR SHOWERS AND MUCH COOLER CONDITIONS WITH GUSTY WINDS. FORECAST MODELS ARE CONSISTENTLY ADVERTISING THIS STRONGER SYSTEM...AND EVEN THOUGH THE SYSTEM LACKS A SIGNIFICANT MOISTURE TAP...COLD AIR ALOFT WILL BE PLENTIFUL AND SHOWERS ARE CERTAINLY POSSIBLE ESPECIALLY OVER THE MOUNTAINS. && .AVIATION...AS OF 4:30 AM PDT WEDNESDAY...SATELLITE IMAGERY SHOWS PATCHY LOW CLOUDS IN MRY BAY AND IN THE SALINAS VALLEY AND ALONG THE SAN MATEO COAST THIS MORNING. STRONG N-S PRESSURE GRADIENT INDICATES DRY NORTHERLY FLOW THAT WILL KEEP CLOUDS OUT OF THE SFO BAY AREA TODAY. VICINITY OF KSFO...VFR. WEST AFTERNOON WINDS TO 20 KT AFTER 20Z. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH 17-18Z. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PIGEON PT TO PT PINOS 0-10 NM GLW...PT ARENA TO PT REYES 10-60 NM GLW...PT REYES TO PIGEON PT 10-60 NM SCA...PT ARENA TO PT REYES 0-10 NM SCA...PT REYES TO PIGEON PT 0-10 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM GLW...PIGEON PT TO PT PINOS 10-60 NM SCA...MONTEREY BAY FROM 1 PM && $$ PUBLIC FORECAST: BELL/KBB AVIATION: W PI 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