Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Francisco Bay area
443 PM PDT Thursday Mar 26 2015
Synopsis...today will be the warmest day of the week as warming
trend continues. Record temperatures will be possible. Dry weather
conditions will also continue through the forecast period with
temperatures cooling slightly over the weekend.
Discussion...as of 02:45 PM PDT Thursday... a strong high pressure
ridge is located directly over California this afternoon.
Temperatures have soared over the last hour with numerous reports
of temperatures in the 70s along the coast and 80s at inland
locations. As of 2pm... downtown San Francisco is running 77f
which is 11f warmer than yesterday at 2pm. Salinas is 88f which is
14 degrees above 2pm yesterday. Mesonet stations near Cupertino
show temperatures around 86f as of 2pm... which is the warmest
pocket within the immediate Bay area. Another 2 to 3 hours of
warming are possible for locations away from the immediate
shoreline as the atmosphere warms to 15-16cat 850mb. Temperatures
at 850mb have risen 4-6c over the last 14 hours and are corresponding
to surface temperatures that are anywhere between 10 and 25f
degrees warmer at the surface. This high pressure system is nearly
2 Standard deviations stronger than normal which typically
corresponds to unseasonably warm temperatures that are within a
few degrees of record values. As of 2pm... record temperatures
are imminent at San Jose...Salinas...Napa...and Gilroy. Oakland
museum is within a few degrees as well...however temperatures
there will not see much additional warming after the next hour.
Temperatures are expected only marginally cooler on Friday as the
ridge shifts downstream into the Great Basin and the offshore
gradients weaken. Regions in the North Bay will see the most
cooling into Friday whereas San Benito County will remain the
The weather pattern shifts early Saturday as a dry frontal
boundary moves into the area. Models are in general agreement that
this system weakens to some degree as it moves over the area...
and that precipitation is unlikely. Onshore flow will increase and
some cooling will occur on Saturday as moisture/clouds return into
the region. Ridging is set to build back into the region next
week... leading to moderately above average temperatures and no
Aviation...as of 4:30 PM PDT Thursday...upper level high bringing
a warm and dry airmass over the area. VFR conditions through the
Vicinity of ksfo...VFR through Friday. Brief period of west
seabreeze winds to 15 knots through 04z.
Sfo bridge approach...similar to ksfo.
Monterey Bay area terminals...VFR through Friday.
Climate...below are record daily high temperatures for Thursday
(3/26) and Friday (3/27):
Thursday 3/26 record Friday 3/27 record
climate station high and year high and year
Sf Bay area...
Kentfield 88 in 1930 90 in 1923
San Rafael 84 in 1988 82 in 1969
Napa 86 in 1988 86 in 1930
San Francisco downtown 82 in 1930 84 in 1923
San Francisco Airport 79 in 1952 77 in 1986
Oakland museum 80 in 1988 79 in 1986
Oakland Airport 80 in 1952 82 in 1951
Richmond 84 in 1970 82 in 1952
Livermore 88 in 1988 82 in 1969
Moffett field 83 in 1988 82 in 1969
San Jose 84 in 1988 85 in 1923
Gilroy 87 in 1997 85 in 1969
Monterey Bay area...
Monterey 84 in 1988 80 in 1969
Santa Cruz 88 in 1988 87 in 1969
Salinas 88 in 1969 85 in 1969
Salinas Airport 87 in 1988 80 in 1969
King City 89 in 1988 86 in 1969
Marine...as of 02:09 PM PDT Thursday...a fairly weak pressure
gradient will lead to light winds through tonight. A thermal
trough will begin to build along the coast Friday resulting in
increasing winds over the coastal waters. These strengthening
winds will generate steep seas through the weekend.
Public forecast: drp
aviation: west pi
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