Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Francisco Bay area
1000 am PST Monday Feb 8 2016
Synopsis...a strong ridge of high pressure will remain positioned
over the West Coast Monday resulting in the potential for record
warmth across the Bay area and central coast today. The ridge
will begin to weaken tomorrow...initiating a cooling trend which
will bring temperatures back to seasonal norms through Valentines
day weekend. Outside of a slight chance for rain over the North
Bay Friday and Friday night, dry weather is forecast.
Discussion...as of 9:00 am PST Monday... an unseasonably strong
588dm high pressure ridge is dominating the regional weather this
morning. This ridge is diverting moisture away from the area and
into British Columbia... leaving the area under a warm...dry...
stagnant air mass. The ridge is forecast to be at peak intensity
today... and temperatures at the ground will make no mistake about
that fact as 850mb temperatures rise to 16-18c. Record to near
record temperatures are possible across the region today as
temperatures warm into the 70s and even as high as the lower 80s
in places however current record highs in the Monterey Bay region
will be difficult to overcome. Downsloping offshore flow will
further exacerbate warming at the surface on the western side of
slopes. Based on yesterdays maximum temperatures... decided to
push out a forecast update with warmer temperatures for today.
Otherwise... forecast looks on track with clear skies...dry
weather... and gradually cooling temperatures through the week.
..from previous discussion...
The ridge axis will shift off to the east starting on Tuesday
which will help to gradually bring temperatures down closer to
normal values. At the same time a longwave trough will approach the
coast and by Friday rain will move from norcal up to British Columbia. For our
region, models show an outside chance of light rain hitting the
North Bay so left a mention of that in the forecast.
Behind the trough the flow will alternate between zonal and a Flat
Ridge at least into next Tuesday. After that, some indication
that moisture could become entrained in the flow and bring rain
back to our region during the middle to end of next week.
Bottom line...no public zone hazards expected through the next 7
Aviation...as of 10 am PST Monday...VFR conditions with clear
skies will prevail through this evening. Offshore flow will
continue with easterlies generally below 10 kts. Slightly stronger
through Carquinez Strait...affecting kapc...as well as klvk and
the Salinas valley into early this afternoon. Winds are expected
to switch to light onshore south of the Bay Bridge with heating
this afternoon into the early evening. Radiational cooling is
expected to lead to IFR stratus and fog around ksts early Tuesday
Vicinity of ksfo...VFR will prevail with light southeast to east
Sfo bridge approach...similar to ksfo.
Monterey Bay area terminals...VFR. Light winds kmtr. Ksns
moderate southeast winds this morning into the early afternoon then
Beaches...as of 10:45 PM PST Friday...swells off the coast have
decreased to 7 to 8 feet tonight but the swell periods continue at
14 to 15 seconds. Although the waves are lower the longer periods
make the waves capable of generating strong rip currents and large
shore break. Additionally...water temperature is only expected to
be in the middle 50s...so those venturing into the water will also be
subject to a heightened risk of hypothermia.
Climate...record highs for Monday...
City name Feb 8th high and year
Kentfield 71 in 2006
San Rafael 72 in 1980
Napa 73 in 1987
San Francisco 74 in 2006
sfo Airport 73 in 2006
Oakland museum 77 in 2006
Oakland Airport 70 in 2006
Richmond 78 in 2011
Livermore 78 in 1917
San Jose 75 in 1987
Gilroy 78 in 1963
Monterey 81 in 1954
Santa Cruz 78 in 1954
Salinas 83 in 2006
Salinas Airport 83 in 1954
King City 84 in 2006
Marine...as of 09:49 am PST Monday...a large ridge of high
pressure over the western states will keep light winds across the
coastal waters today. Offshore winds will continue through Tuesday
morning as the surface thermal trough shifts to the coast.
Offshore winds will be gusty in the vicinity of the coastal
mountain gaps. Onshore flow will return Tuesday as the high
weakens. A long period swell will arrive in the waters today.
Public forecast: drp
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