Area Forecast Discussion
FXUS66 KMTR [Monterey CA] 051154 AFDMTR ∨
FXUS66 KMTR 051154 AFDMTR [HEAD]
National Weather Service San Francisco Bay Area 4:54am PDT Sat Sep 5 2015 ∨
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 454 AM PDT SAT SEP 5 2015 [HEAD]
Synopsis. A region-wide warming trend is forecast to begin this weekend and continue into much of next week as high pressure builds over the state. Dry weather conditions will also continue through next week. ∨
.SYNOPSIS...A REGION-WIDE WARMING TREND IS FORECAST TO BEGIN THIS WEEKEND AND CONTINUE INTO MUCH OF NEXT WEEK AS HIGH PRESSURE BUILDS OVER THE STATE. DRY WEATHER CONDITIONS WILL ALSO CONTINUE THROUGH NEXT WEEK. [DISC]
Discussion. As of 04:14am PDT Saturday… a cooler and drier air mass continues to filter into the region this morning in wake of yesterday's passing short-wave disturbance. This feature also helped to keep the marine layer from redeveloping much overnight… with only patchy coastal stratus along the San Mateo coast and around the southern portion of the Monterey Bay. These clouds are forecast to burn-off shortly after sunrise with mostly sunny conditions expected region-wide for the remainder of the day. As the broad mid/upper level trough over the Pacific Northwest pushes further inland today… weak offshore flow will develop off the surface and allow for warming temperatures this afternoon. While temperatures will generally remain below seasonal averages today… most locations will be a few degrees warmer compared to Friday afternoon. ∨
.DISCUSSION...AS OF 04:14 AM PDT SATURDAY...A COOLER AND DRIER AIR MASS CONTINUES TO FILTER INTO THE REGION THIS MORNING IN WAKE OF YESTERDAY`S PASSING SHORT-WAVE DISTURBANCE. THIS FEATURE ALSO HELPED TO KEEP THE MARINE LAYER FROM REDEVELOPING MUCH OVERNIGHT...WITH ONLY PATCHY COASTAL STRATUS ALONG THE SAN MATEO COAST AND AROUND THE SOUTHERN PORTION OF THE MONTEREY BAY. THESE CLOUDS ARE FORECAST TO BURN-OFF SHORTLY AFTER SUNRISE WITH MOSTLY SUNNY CONDITIONS EXPECTED REGION-WIDE FOR THE REMAINDER OF THE DAY. AS THE BROAD MID/UPPER LEVEL TROUGH OVER THE PACIFIC NORTHWEST PUSHES FURTHER INLAND TODAY...WEAK OFFSHORE FLOW WILL DEVELOP OFF THE SURFACE AND ALLOW FOR WARMING TEMPERATURES THIS AFTERNOON. WHILE TEMPERATURES WILL GENERALLY REMAIN BELOW SEASONAL AVERAGES TODAY...MOST LOCATIONS WILL BE A FEW DEGREES WARMER COMPARED TO FRIDAY AFTERNOON. [DISC]
A more robust warming trend is then expected Sunday into Monday as mid/upper level high pressure over the southwest portion of the country builds westward… resulting in warming 850 mb temperatures and continued offshore flow in the lower levels. Surface temperatures early next week will be around 5–7° above seasonal averages. The warming trend will then likely continue into midweek as 850 mb temperatures are forecast to approach or exceed 20°C. This will push temperatures near the coast into the mid/upper 70s to near 80 with inland areas warming into the mid/upper 80s to mid/upper 90s in the warmest inland valleys. With the broad mid/upper level ridge forecast to remain over the West Coast for much of next week… dry weather conditions along with above average temperatures will likely persist. In addition… low clouds will likely remain absent for much of the forecast period with dry boundary layer conditions as a result of the weak offshore flow off the surface. ∨
A MORE ROBUST WARMING TREND IS THEN EXPECTED SUNDAY INTO MONDAY AS MID/UPPER LEVEL HIGH PRESSURE OVER THE SOUTHWEST PORTION OF THE COUNTRY BUILDS WESTWARD...RESULTING IN WARMING 850MB TEMPERATURES AND CONTINUED OFFSHORE FLOW IN THE LOWER LEVELS. SURFACE TEMPERATURES EARLY NEXT WEEK WILL BE AROUND 5-7 DEGREES ABOVE SEASONAL AVERAGES. THE WARMING TREND WILL THEN LIKELY CONTINUE INTO MIDWEEK AS 850MB TEMPERATURES ARE FORECAST TO APPROACH OR EXCEED 20 DEG C. THIS WILL PUSH TEMPERATURES NEAR THE COAST INTO THE MID/UPPER 70S TO NEAR 80 WITH INLAND AREAS WARMING INTO THE MID/UPPER 80S TO MID/UPPER 90S IN THE WARMEST INLAND VALLEYS. WITH THE BROAD MID/UPPER LEVEL RIDGE FORECAST TO REMAIN OVER THE WEST COAST FOR MUCH OF NEXT WEEK...DRY WEATHER CONDITIONS ALONG WITH ABOVE AVERAGE TEMPERATURES WILL LIKELY PERSIST. IN ADDITION...LOW CLOUDS WILL LIKELY REMAIN ABSENT FOR MUCH OF THE FORECAST PERIOD WITH DRY BOUNDARY LAYER CONDITIONS AS A RESULT OF THE WEAK OFFSHORE FLOW OFF THE SURFACE. [DISC]
While this pattern will result in great weather conditions for beachgoers this Labor Day weekend… a long period southerly swell moving into the waters will result in hazardous conditions in the surf zone. The primary concern will be from dangerous rip currents and large shore break along the south and southwest-facing beaches this weekend. Anyone visiting area beaches this weekend are urged to use caution and remember to never turn your back to the ocean. ∨
WHILE THIS PATTERN WILL RESULT IN GREAT WEATHER CONDITIONS FOR BEACHGOERS THIS LABOR DAY WEEKEND...A LONG PERIOD SOUTHERLY SWELL MOVING INTO THE WATERS WILL RESULT IN HAZARDOUS CONDITIONS IN THE SURF ZONE. THE PRIMARY CONCERN WILL BE FROM DANGEROUS RIP CURRENTS AND LARGE SHORE BREAK ALONG THE SOUTH AND SOUTHWEST-FACING BEACHES THIS WEEKEND. ANYONE VISITING AREA BEACHES THIS WEEKEND ARE URGED TO USE CAUTION AND REMEMBER TO NEVER TURN YOUR BACK TO THE OCEAN. [DISC]
Aviation. As of 4:42am PDT Saturday… moderate to strong northerly pressure gradients continue this morning… ACV [Arcata/Eureka CA]-SFO [San Francisco CA] 4.8 mb and uki-STS [Santa Rosa CA] 2.4 mb. Lower humidity area-wide from the lower to the upper levels is allowing for near optimum nocturnal cooling and surface wind de-coupling resulting in light/variable valley winds. Northerly gradients forecast to persist as surface high pressure builds over Eastern Pacific/northernmost California and briefly over to the Great Basin tonight. Mid-upper level high will strengthen through the period. ∨
.AVIATION...AS OF 4:42 AM PDT SATURDAY...MODERATE TO STRONG NORTHERLY PRESSURE GRADIENTS CONTINUE THIS MORNING...ACV-SFO 4.8 MB...AND UKI-STS 2.4 MB. LOWER HUMIDITY AREA-WIDE FROM THE LOWER TO THE UPPER LEVELS IS ALLOWING FOR NEAR OPTIMUM NOCTURNAL COOLING AND SURFACE WIND DE-COUPLING RESULTING IN LIGHT/VARIABLE VALLEY WINDS. NORTHERLY GRADIENTS FORECAST TO PERSIST AS SURFACE HIGH PRESSURE BUILDS OVER EPAC/NORTHERNMOST CA AND BRIEFLY OVER TO THE GREAT BASIN TONIGHT. MID-UPPER LEVEL HIGH WILL STRENGTHEN THROUGH THE PERIOD. [AVIA]
Vicinity of KSFO [San Francisco CA]… VFR [Visual Flight Rules]. ∨
VICINITY OF KSFO...VFR. [AVI2]
KSFO [San Francisco CA] bridge approach… VFR [Visual Flight Rules]. ∨
KSFO BRIDGE APPROACH...VFR. [AVI2]
Monterey Bay Area terminals… NW winds forcing narrow band of low clouds to persist over the southern Monterey Bay Area. KMRY [Monterey CA] scattered-broken til about 16Z [9am PDT] today otherwise should see sufficient vertical mixing of drier air to provide clearing. (VFR [Visual Flight Rules].) ∨
MONTEREY BAY AREA TERMINALS...NW WINDS FORCING NARROW BAND OF LOW CLOUDS TO PERSIST OVER THE SOUTHERN MONTEREY BAY AREA. KMRY SCT-BKN TIL ABOUT 16Z TODAY OTHERWISE SHOULD SEE SUFFICIENT VERTICAL MIXING OF DRIER AIR TO PROVIDE CLEARING. VFR. [AVI2]
Marine. As of 04:14am PDT Saturday… high pressure over the eastern Pacific and northernmost California will keep gusty northwest winds going over the coastal waters through tonight. A long period southerly swell will move into the coastal waters over the weekend resulting in hazardous conditions alongshore. ∨
.MARINE...AS OF 04:14 AM PDT SATURDAY...HIGH PRESSURE OVER THE EASTERN PACIFIC AND NORTHERNMOST CALIFORNIA WILL KEEP GUSTY NORTHWEST WINDS GOING OVER THE COASTAL WATERS THROUGH TONIGHT. A LONG PERIOD SOUTHERLY SWELL WILL MOVE INTO THE COASTAL WATERS OVER THE WEEKEND RESULTING IN HAZARDOUS CONDITIONS ALONGSHORE. [AVIA]
.MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT ARENA TO PT REYES 0-10 NM 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 PIGEON PT 10-60 NM SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM [WARN]
Public Forecast: Rgass; Aviation/Marine: Canepa ∨
PUBLIC FORECAST: RGASS AVIATION/MARINE: CANEPA [CRED]
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO [LINK]
FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA [DISC]
05 Sep 8:55am PDT
Today Sunny, with a high near 72°. WNW wind 9 to 17 mph, with gusts as high as 22 mph.
Tonight Mostly clear, with a low around 56°. WNW wind 6 to 15 mph, with gusts as high as 18 mph.
Sunday Sunny, with a high near 74°. Light west wind increasing to 5 to 9 mph in the afternoon.
Sunday Night Partly cloudy, with a low around 56°. WSW wind 5 to 10 mph.
Labor Day Mostly sunny, with a high near 74°. Light and variable wind.
Monday Night Partly cloudy, with a low around 56°.
Tuesday Mostly sunny, with a high near 74°.
Tuesday Night Mostly clear, with a low around 57°.
Wednesday Sunny, with a high near 74°.
Wednesday Night Mostly clear, with a low around 57°.
Thursday Sunny, with a high near 75°.
Thursday Night Mostly clear, with a low around 58°.
Friday Sunny, with a high near 75°.
Sunny, with a high near 72. West northwest wind 9 to 17 mph, with gusts as high as 22 mph.
Mostly clear, with a low around 56. West northwest wind 6 to 15 mph, with gusts as high as 18 mph.
Sunny, with a high near 74. Light west wind increasing to 5 to 9 mph in the afternoon.
Partly cloudy, with a low around 56. West southwest wind 5 to 10 mph.
Mostly sunny, with a high near 74. Light and variable wind.
Partly cloudy, with a low around 56.
Mostly sunny, with a high near 74.
Mostly clear, with a low around 57.
Sunny, with a high near 74.
Mostly clear, with a low around 57.
Sunny, with a high near 75.
Mostly clear, with a low around 58.
Sunny, with a high near 75.