Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Francisco Bay area
952 am PST sun Jan 25 2015
Synopsis...dry weather and unseasonably warm temperatures will
persist through Monday as the region remains under the influence
of a strong ridge of high pressure. A weak storm system will then
approach Southern California Monday night into Tuesday and bring a
chance of light precipitation to the central coast.
Discussion...as of 8:52 am PST Sunday...visible satellite imagery
shows low clouds and fog have spread from the Central Valley into the
East Bay and North Bay valleys. Currently only Santa Rosa Airport
is indicating dense fog (1/4 mile)...with 1 to 3 miles at
Concord...Livermore and Napa airports. Expect these conditions to
slowly improve through the morning...but in currently foggy/cloudy
areas there will naturally be a delay to the daytime heating.
High pressure aloft and offshore surface flow will lead to another
warm day across much of the district with highs forecast to range
from the middle 60s to around 80. Near record warmth is again
expected for much of the region as temperatures warm into the 70s
to near 80 south of the greater San Francisco Bay area. Light
offshore winds across the San Francisco Bay should help to keep
temperatures in the middle to upper 60s across that area with
portions of the East Bay and North Bay reaching into the lower
70s. The warmest areas will be across inland Monterey and San
Benito counties where lower 80s will be possible.
Early in the week the upper ridge will begin to shift eastward as
a disturbance over Southern California and Arizona begins to move
to the north. This could advect some moisture into the southern
zones...thus a slight chance of light rain is possible across
mainly the southern half of the district...and most likely
Monterey and San Benito counties on Tuesday morning. By later in
the day the disturbance will eject to the east and shower chances
will end. Dry and mild conditions are indicated for the rest of
the week as the area remains under weak high pressure.
Aviation...as of 9:50 am PST Sunday... portions of the north and
East Bay interior valleys under low clouds and fog this morning.
These areas should improve around 19z however lingering haze will
persist through the day. Otherwise... VFR with light offshore
winds. Broken to overcast high clouds will move in from the south a few
hours before sunrise Monday.
Vicinity of ksfo...VFR. Light offshore winds.
Ksfo bridge approach...similar to ksfo except areas of haze.
Monterey Bay area terminals...VFR. Light southeast winds except up to
10-12 knots at ksns.
Climate...record high temperatures are possible over the area today.
Here is the list of records along with the January warmest high
temperature readings and the latest year they occurred.
Sf Bay area...
Location today (1/25) January warmest
Kentfield 77/1934 79/1962
San Rafael 70/2014 82/1962
Napa 83/1899 85/1962
San Francisco 74/1899 79/1962
sfo Airport 68/2011 73/2014
Oakland 73/2014 78/2014
Oak Airport 70/2014 77/2014
Richmond 69/2011 76/1962
Livermore 73/1911 77/1911
Mountain View 72/2014 76/1948
San Jose 71/2014 79/1962
Gilroy 77/2014 80/2014
North central coast...
Monterey 78/1942 84/2014
Santa Cruz 80/1899 84/2014
Salinas 78/2014 87/2014
sns Airport 78/2014 86/2014
King City 77/2014 86/1976
Marine...as of 09:46 am PST Sunday...high pressure shifts
downstream and weakens over the coastal waters through the next 24
hours. Offshore flow will persist into early next week along the
coastline with southerly flow prevailing further offshore.
Northerly winds return late Wednesday/early Thursday. The large
long period swell has tapered off but will continue to impact the
coastal waters through this afternoon. This long period swell will
result in large breakers near bars...Shoals and jetties leading to
hazardous conditions along the coast.
... Surf advisory...entire coast from Sonoma County
through Monterey County through 3pm
Public forecast: Sims
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