Area Forecast Discussion
FXUS66 KMTR [Monterey CA] 112135 AFDMTR ∨
FXUS66 KMTR 112135 AFDMTR [HEAD]
National Weather Service San Francisco Bay Area 2:35pm PDT Tue Mar 11 2014 ∨
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA 235 PM PDT TUE MAR 11 2014 [HEAD]
Synopsis. The offshore surface pressure gradient is expected to increase later this evening and will result in breezy offshore winds through the overnight hours. The strongest winds are expected to occur over the North and East Bay hills. However mixing will promote gusts reaching into some lower elevations in the San Francisco Bay Area. A ridge of high pressure will continue to build over the east Pacific and West Coast. This building ridge will result in a warming trend which will persist through the upcoming weekend with afternoon temperatures in the upper 60s and mid 70s at the coast and mid 70s to upper 80s inland Saturday and Sunday. ∨
.SYNOPSIS...THE OFFSHORE SURFACE PRESSURE GRADIENT IS EXPECTED TO INCREASE LATER THIS EVENING AND WILL RESULT IN BREEZY OFFSHORE WINDS THROUGH THE OVERNIGHT HOURS. THE STRONGEST WINDS ARE EXPECTED TO OCCUR OVER THE NORTH AND EAST BAY HILLS. HOWEVER MIXING WILL PROMOTE GUSTS REACHING INTO SOME LOWER ELEVATIONS IN THE SAN FRANCISCO BAY AREA. A RIDGE OF HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE EAST PACIFIC AND WEST COAST. THIS BUILDING RIDGE WILL RESULT IN A WARMING TREND WHICH WILL PERSIST THROUGH THE UPCOMING WEEKEND WITH AFTERNOON TEMPERATURES IN THE UPPER 60S AND MID 70S AT THE COAST AND MID 70S TO UPPER 80S INLAND SATURDAY AND SUNDAY. [DISC]
Discussion. As of 2:34pm PDT Tuesday… the current visible satellite image is showing sunny skies across the forecast area this afternoon. Under sunny skies afternoon temperatures have risen into the upper 60s to low 70s. Monterey Airport is reporting a temperature of 70° which is 9° warmer than observed at this hour yesterday… Watsonville is 6° warmer reporting a temperature of 71 and SFO [San Francisco CA] is 1° warmer with a temperature of 62. ∨
.DISCUSSION...AS OF 2:34 PM PDT TUESDAY...THE CURRENT VISIBLE SATELLITE IMAGE IS SHOWING SUNNY SKIES ACROSS THE FORECAST AREA THIS AFTERNOON. UNDER SUNNY SKIES AFTERNOON TEMPERATURES HAVE RISEN INTO THE UPPER 60S TO LOW 70S. MONTEREY AIRPORT IS REPORTING A TEMPERATURE OF 70 DEGREES WHICH IS 9 DEGREES WARMER THAN OBSERVED AT THIS HOUR YESTERDAY...WATSONVILLE IS 6 DEGREES WARMER REPORTING A TEMPERATURE OF 71 AND SFO IS 1 DEGREE WARMER WITH A TEMPERATURE OF 62. [DISC]
Gusty east northeast winds are expected to develop by this evening. The strongest winds are anticipated in the North Bay mountains where gusts could reach 50 mph. Some of this wind could mix to the surface where wind gusts could top 45 mph. Therefore have issued a Wind Advisory for a majority of the North Bay and San Francisco Bay Area for this evening into Wednesday morning. For more information please see SFONPWMTR. ∨
GUSTY EAST NORTHEAST WINDS ARE EXPECTED TO DEVELOP BY THIS EVENING. THE STRONGEST WINDS ARE ANTICIPATED IN THE NORTH BAY MOUNTAINS WHERE GUSTS COULD REACH 50 MPH. SOME OF THIS WIND COULD MIX TO THE SURFACE WHERE WIND GUSTS COULD TOP 45 MPH. THEREFORE HAVE ISSUED A WIND ADVISORY FOR A MAJORITY OF THE NORTH BAY AND SAN FRANCISCO BAY AREA FOR THIS EVENING INTO WEDNESDAY MORNING. FOR MORE INFORMATION PLEASE SEE SFONPWMTR. [DISC]
The 1200Z [5am PDT] ECMWF [European Center for Medium-Range Weather Forecasts model] and GFS40 [Global Forecast System: global spectral model used primarily for aviation weather forecasts; provides guidance out to 384 hours at 00, 06, 12 and 18UTC.] have initialized well with the current synoptic pattern and remain in good agreement through at least Monday evening. Both models continue to build a ridge of high pressure over the eastern Pacific with an inside slider pushing south along the Sierra into southern Nevada tonight. At the surface this will result in a fairly strong offshore surface pressure gradient. The 1200Z [5am PDT] NAM12 [North American Meso (formerly Eta) model] and GFS40 [Global Forecast System: global spectral model used primarily for aviation weather forecasts; provides guidance out to 384 hours at 00, 06, 12 and 18UTC.] as well as our higher resolution models are indicating that 925 mb winds will reach 40–50 kt [46–58 mph] across the North Bay mountains this evening lasting into the overnight hours. By Wednesday mid morning the low pressure system pushes further south east and the surface pressure gradient begins to weaken resulting in decreasing offshore winds. ∨
THE 1200Z ECMWF AND GFS40 HAVE INITIALIZED WELL WITH THE CURRENT SYNOPTIC PATTERN AND REMAIN IN GOOD AGREEMENT THROUGH AT LEAST MONDAY EVENING. BOTH MODELS CONTINUE TO BUILD A RIDGE OF HIGH PRESSURE OVER THE EASTERN PACIFIC WITH AN INSIDE SLIDER PUSHING SOUTH ALONG THE SIERRA INTO SOUTHERN NEVADA TONIGHT. AT THE SURFACE THIS WILL RESULT IN A FAIRLY STRONG OFFSHORE SURFACE PRESSURE GRADIENT. THE 1200Z NAM12 AND GFS40 AS WELL AS OUR HIGHER RESOLUTION MODELS ARE INDICATING THAT 925MB WINDS WILL REACH 40 TO 50 KT ACROSS THE NORTH BAY MOUNTAINS THIS EVENING LASTING INTO THE OVERNIGHT HOURS. BY WEDNESDAY MID MORNING THE LOW PRESSURE SYSTEM PUSHES FURTHER SOUTH EAST AND THE SURFACE PRESSURE GRADIENT BEGINS TO WEAKEN RESULTING IN DECREASING OFFSHORE WINDS. [DISC]
According to the forecast models the ridge of high pressure begins to slide east Friday pushing 500 mb heights to around 573–576 dm [decameters] along the coast. By Saturday the ridge builds to around 582 dm [decameters] over the San Francisco Bay Area. This building ridge will promote a warming trend with afternoon high temperatures reaching the mid 70s to lower 80s inland and low to mid 70s along the coast. With generally light offshore winds at the surface it looks like a great time to get out and enjoy the outdoors from mid week through the weekend! Just remember to drink plenty of water and use Sun screen. ∨
ACCORDING TO THE FORECAST MODELS THE RIDGE OF HIGH PRESSURE BEGINS TO SLIDE EAST FRIDAY PUSHING 500MB HEIGHTS TO AROUND 573 TO 576 DM ALONG THE COAST. BY SATURDAY THE RIDGE BUILDS TO AROUND 582DM OVER THE SAN FRANCISCO BAY AREA. THIS BUILDING RIDGE WILL PROMOTE A WARMING TREND WITH AFTERNOON HIGH TEMPERATURES REACHING THE MID 70S TO LOWER 80S INLAND AND LOW TO MID 70S ALONG THE COAST. WITH GENERALLY LIGHT OFFSHORE WINDS AT THE SURFACE IT LOOKS LIKE A GREAT TIME TO GET OUT AND ENJOY THE OUTDOORS FROM MID WEEK THROUGH THE WEEKEND! JUST REMEMBER TO DRINK PLENTY OF WATER AND USE SUN SCREEN. [DISC]
Aviation. As of 10:30am PDT Tuesday… VFR [Visual Flight Rules] conditions will prevail through the forecast. Breezy northeast winds will continue over the next few hours… before briefly turning onshore early this afternoon. Winds will switch once again to a northeast direction later this evening into the overnight hours. ∨
.AVIATION...AS OF 10:30 AM PDT TUESDAY...VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST. BREEZY NORTHEAST WINDS WILL CONTINUE OVER THE NEXT FEW HOURS...BEFORE BRIEFLY TURNING ONSHORE EARLY THIS AFTERNOON. WINDS WILL SWITCH ONCE AGAIN TO A NORTHEAST DIRECTION LATER THIS EVENING INTO THE OVERNIGHT HOURS. [AVIA]
Vicinity of KSFO [San Francisco CA]… VFR [Visual Flight Rules]. ∨
VICINITY OF KSFO...VFR. [AVI2]
KSFO [San Francisco CA] bridge approach… similar to KSFO [San Francisco CA]. ∨
KSFO BRIDGE APPROACH...SIMILAR TO KSFO. [AVI2]
Monterey Bay Area terminals… VFR [Visual Flight Rules]. ∨
MONTEREY BAY AREA TERMINALS...VFR. [AVI2]
Marine. As of 1:45pm PDT Tuesday… a long period northwest swell will enter the waters by Wednesday afternoon. Initially… swell period will range from 19–20 seconds with a swell height generally between 3 and 5 feet. As Wednesday continues… swell heights will increase as the period decreases. These long period swells will bring an enhanced risk of rip currents… sneaker waves and occasional large surf. Please continue to monitor the forecast for the latest information. ∨
.MARINE...AS OF 1:45 PM PDT TUESDAY...A LONG PERIOD NORTHWEST SWELL WILL ENTER THE WATERS BY WEDNESDAY AFTERNOON. INITIALLY...SWELL PERIOD WILL RANGE FROM 19 TO 20 SECONDS WITH A SWELL HEIGHT GENERALLY BETWEEN 3 AND 5 FEET. AS WEDNESDAY CONTINUES...SWELL HEIGHTS WILL INCREASE AS THE PERIOD DECREASES. THESE LONG PERIOD SWELLS WILL BRING AN ENHANCED RISK OF RIP CURRENTS...SNEAKER WAVES...AND OCCASIONAL LARGE SURF. PLEASE CONTINUE TO MONITOR THE FORECAST FOR THE LATEST INFORMATION. [AVIA]
.MTR WATCHES/WARNINGS/ADVISORIES... .TNGT...WIND ADVISORY...NORTH BAY...EAST BAY...SF PENINSULA COAST ...AND SF SHORELINE STARTING AT 8 PM SCA...PT ARENA TO PT REYES 10-60 NM UNTIL 3 PM SCA...PT REYES TO PIGEON PT 10-60 NM UNTIL 3 PM SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 3 PM [WARN]
Public Forecast: Larry; Aviation: Riley; Marine: Riley ∨
PUBLIC FORECAST: LARRY AVIATION: RILEY MARINE: RILEY [CRED]
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1:49pm PDT Mar 11 2014
This Afternoon. Sunny, with a high near 65°. North wind around 9 mph.
Tonight. Clear, with a low around 48°. Breezy, with an ENE wind 7 to 17 mph increasing to 18 to 28 mph after midnight. Winds could gust as high as 34 mph.
Wednesday. Sunny, with a high near 67°. Breezy, with an east wind 18 to 28 mph decreasing to 5 to 15 mph in the afternoon. Winds could gust as high as 34 mph.
Wednesday Night. Clear, with a low around 50°. NNW wind around 6 mph becoming calm in the evening.
Thursday. Sunny, with a high near 63°. Light SW wind.
Thursday Night. Partly cloudy, with a low around 48°.
Friday. Mostly sunny, with a high near 63°.
Friday Night. Mostly clear, with a low around 50°.
Saturday. Sunny, with a high near 68°.
Saturday Night. Mostly clear, with a low around 53°.
Sunday. Sunny, with a high near 69°.
Sunday Night. Mostly clear, with a low around 51°.
Monday. Sunny, with a high near 64°.