Scientific Forecaster Discussion
fxus66 kmtr 270531
Area forecast discussion
National Weather Service San Francisco Bay area
1031 PM PDT sun Mar 26 2017
Synopsis...a cold front will move southeast across the Bay area
and north central coast this evening and overnight. Rain with this
front will continue to spread southeastward tonight then gradually
taper off to showers Monday morning. Decreasing clouds Monday will
be followed by brisk afternoon and evening northwest winds. High
pressure will quickly build back over northern California Tuesday
and persist through late week resulting in dry weather and slightly
warmer than average temperatures for late March and early April.
Discussion...as of 8:49 PM PDT Sunday...a cold front over the
eastern Pacific will continue to press southeastward across the
Bay area and north central coast this evening and overnight. Brief
mid level warm air advection mainly earlier today ahead of the
cold front will continue to quickly shift south-southeastward
parallel to the California coast and become replaced by cold air
advection later tonight into Monday morning. Rain with this front
will continue to spread southeastward as well then gradually taper
off to showers Monday morning. 850 mb temperatures lowering from
5c this evening to approx 0c-2c Monday sets the stage for a chilly
and brisk Monday despite a late March sun angle. After this point
an upper level ridge will build in quickly bringing a quick turn
around to milder temperatures from Tuesday through late week.
Temperatures from Tuesday Onward through late week and next
weekend will become slightly warmer than average for late March
and early April.
Aviation...as of 10:31 PM PDT Sunday...for 06z tafs. Weak front
is now moving east of the area with -shra activity quickly winding
down. Winds are switching NW and drier air is filtering in.
Question is what will be left in terms of low clouds for the early
morning hours. Best guidance currently suggests any morning cigs
should quickly mix out with strong boundary layer winds and drying
Vicinity of ksfo...northwest winds have arrive and rain should now
be done for the night. MVFR cigs forecast to mix out by 16z.
Sfo bridge approach...similar to ksfo.
Monterey Bay terminals...showers quickly moving eastward.
Lingering boundary layer moisture and MVFR cigs should mix out by
Marine...as of 9:00 PM PDT Sunday...winds will continue to
switch to the northwest overnight as a weak cold front passes
through the waters. Northwest winds will increase Monday afternoon
through Tuesday as a strong surface pressure gradient sets up
across the region. At the same time a building northwest swell
will pass through the waters but become messy in the near shore
waters due to the strong winds. Typical gusty Spring Time
northwest winds will continue at least through midweek and likely
through Friday as the next weather system will likely increase the
surface pressure gradient once again.
Public forecast: canepa
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