Scientific Forecaster Discussion
fxus66 kmtr 272043
Area forecast discussion
National Weather Service San Francisco Bay area
143 PM PDT Sat may 27 2017
Synopsis...dry with seasonable temperatures expected for much of
the Holiday weekend. The next trough and associated cooling trend
arrives Tuesday and Wednesday with long range trends indicating a
dry and benign weather pattern continuing.
Discussion...as of 1:43 PM PDT Saturday...visible satellite
imagery shows that the low clouds have cleared to just the
northern Sonoma County coast, with afternoon temperatures all
trending warmer than yesterday at this time. Current readings are
ranging from the 60s at the coast to the 70s inland.
Additional warming is expected on Sunday and through Memorial Day
as a high pressure ridge moves across California. This ridge is
expected to compress the marine layer, thus coastal low clouds
and fog are likely to form tonight with some spreading into inland
valleys as well. Highs on Sunday and Monday are expected to range
from the 60s at the coast to the mid 80s in the warmest, inland
The high pressure ridge will gradually weaken beginning on Tuesday
as an upper level trough approaches the coast. This will bring
cooler temperatures to the area through Thursday with increased
marine clouds and onshore flow. High pressure aloft to rebuild
slightly by the end of the week for warmer temperatures going into
Aviation...as of 10:35 am PDT Saturday...satellite shows the low
clouds beginning to thin out and expect the through mid-day.
Expect VFR conditions for the early afternoon with generally light
winds (though could be a bit stronger along the coast). Cloud
cover will increase again by evening and overnight with ceilings
transitioning back to MVFR/IFR. Expect ceilings to be lower
tomorrow morning as subsidence aloft aids to compressing the
Vicinity of ksfo...skies are beginning to transition over the
terminal with the latest obs in the last 15 minutes going from broken
to scattered. VFR conditions expected through the evening with west
winds up to 15 to 20 kt. Low clouds will return overnight and back
to MVFR ceilings.
Sfo bridge approach...similar to ksfo.
Monterey Bay terminals...low clouds continue to hang over kmry and
ksns this morning, though expect them to become scattered/few within the
next few hours. Onshore winds 10 to 15 kt expected this afternoon
could become a bit gusty. Clouds return overnight with lower
ceilings expected than this morning.
Marine...as of 9:15 am PDT Saturday...light west winds this
morning will increase and become northwest through the afternoon
and continue through the Memorial Day weekend. The swell train
will be generally 5 feet or less through the forecast period so
wind waves will dominate the sea state.
... Pinos to pt Piedras Blancas 0-10 nm
Small Craft Advisory...mry Bay until 9 PM
Public forecast: Sims
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