Scientific Forecaster Discussion
fxus66 kmtr 290350
Area forecast discussion
National Weather Service San Francisco Bay area
850 PM PDT Fri Apr 28 2017
Synopsis...sunny and warmer today and becoming breezy again
tonight in the hills under offshore flow and clear skies. Winds
will ease Saturday morning giving way to a clear and warm weekend.
Another round of offshore winds possible Monday morning otherwise
continued seasonably warm and dry through Wednesday. Cooling
trend may start by the end of next week.
Discussion...as of 8:50 PM PDT Friday...clear skies and breezy
conditions prevail this evening under the continued influence of
high pressure across the region. Temperatures finished off the day
under clear skies and temperatures in the 60s along the coast and
70s inland with moderate north to northwesterly winds around 10
to 20 mph.
A thermal trough situated along the California coast coupled with
high pressure ridging across the Pacific northwest will result in
a tighter pressure gradient across northern and central California
tonight. The northerly gradient from acv to sfo is currently at 7
mb and expected to strengthen overnight. While not as strong as
yesterday northerly winds are forecast to increase to around 15 to
25 mph tonight into Saturday morning with gusts to around 35 mph.
Strongest winds will be over the elevated terrain of the north
and east bays.
Winds should taper by midday Saturday but remain mainly offshore
as high pressure fills in over the Great Basin. The gradual
warming trend that we have seen over the last couple of day will
kick into high gear Saturday and continue through early next week.
Temperatures will warm anywhere from 3 to 6 degrees Saturday with
an increase of 2 to 3 degrees each day thereafter. High in the
70s and 80s are expected across the region this weekend with some
lower 90s expected in the warmest inland valleys early next week.
Warmest days are expected to be Tuesday and Wednesday.
Winds will remain mostly offshore through midweek with some
period of gusty winds possible as the combination of the thermal
trough and strengthening high pressure over the eastern Pacific
tighten the gradient over the region once again.
Clear skies and warm temperatures will prevail through midweek
before the ridge of high pressure begins to break down over the
West Coast. By Thursday temperatures will begin to cool back down
to seasonal norms with widespread 60s and 70s. Until then please
use caution when outdoor and protect Young children, the elderly
and pets from dehydration, sunburns and heat exhaustion while
never leaving children or pets unattended in vehicles.
Aviation...as of 4:30 PM PDT Friday...for 00z tafs. VFR through
the forecast period. Locally gusty west to northwest winds this
evening will gradually diminish overnight. Winds will not be as
strong on Saturday afternoon/evening.
Vicinity of ksfo...VFR. West-northwest winds gusting to around 30 knots at
ksfo through 04z then gradually diminishing through the remainder
of the evening and overnight. Winds late Saturday afternoon will
not be as strong as late Friday.
Sfo bridge approach...similar to ksfo except winds not quite as
Monterey Bay terminals...VFR. Moderate west winds late afternoon
and early evening. Otherwise light winds.
Marine...as of 2:20 PM PDT Friday...northwest winds will remain
strong and gusty through the weekend as high pressure sits off the
coast. Occasional gale force gusts are possible across the
coastal waters. Steep fresh swells with relatively short periods
will make seas hazardous this weekend... in addition to the gusty
... Arena to pt Reyes 0-10 nm
Small Craft Advisory...pt Reyes to Pigeon pt 0-10 nm
Small Craft Advisory...Pigeon pt to pt pinos 0-10 nm
Small Craft Advisory...pt pinos to pt Piedras Blancas 0-10 nm
Small Craft Advisory...pt Arena to Pigeon pt 10-60 nm
Small Craft Advisory...Pigeon pt to pt Piedras Blancas 10-60 nm
Small Craft Advisory...mry Bay until 3 am
Public forecast: CW
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