Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Francisco Bay area
345 am PST Friday Jan 30 2015
Synopsis...dry conditions are expected to continue into next
week with chances of rain only over far northern California.
Temperatures will remain several degrees above normal for the next
Discussion...as of 3:14 am PST Friday...stratus is setting up
along the coast and starting to push into the Bay area. Currently
the areas picking up fog are limited to the North Bay
valleys...but expect patchy fog in more places by morning. Current
temperatures are running mainly in the 40s across the district
except around sfo and on peninsula where lower 50s are occurring.
Highs today are expected to be in the 60s to lower 70s.
Tonight when an upper low now over socal moves to the east...a
surface high will move over the northern Great Basin which will
increase northerly winds over the hills. The latest nam12
increases 925mb winds to around 30 knots overnight tonight and
Saturday morning mainly over the north and East Bay hills.
Meanwhile...northern California remains under a stagnant weather
pattern with an upper ridge nosing into the Pacific northwest and
over northern California. The high pressure ridge will continue to
shunt all rain chances well north of our district through the
forecast period. In addition...high temperatures are expected to
be above normal through the period.
Medium range models continue to hold onto some hope for rain
possibly spreading into northern California by late next week.
Both the European model (ecmwf) and GFS bring rain to northern California beginning
next Friday and Saturday. The Gem...however...keeps the ridge
intact for continued dry conditions for northern California.
Aviation...as of 3:45 am PST Friday...the current satellite fog
product is showing stratus along the coast and in San Francisco
Bay this morning. The GOES-west LIFR probability product is also
indicating a high probability of stratus in San Francisco
Bay...stretching south into the Santa Clara Valley.
Vicinity of ksfo...IFR conditions are expected to impact the
terminals beginning around 1400z burning off around 1800z. West
winds are expected to increase to 15 knots with the afternoon sea
Confidence is moderate.
Ksfo bridge approach...similar to ksfo.
Monterey Bay area terminals...LIFR to IFR conditions are
anticipated to prevail through around 1700z this morning. VFR is
then anticipated through 0200z at kmry and 0500z at ksns. The sea
breeze is expected to reach 5 to 10 knots this afternoon.
Confidence is moderate.
Marine...as of 2:37 am PST Friday...a thermal trough will
maintain moderate northerly winds across the coastal waters today
into Saturday. The strongest winds are expected to occur over the
outer coastal waters. These winds will result in choppy sea
conditions. Wind and sea conditions are expected to improve
Saturday as the thermal trough weakens...light winds are then
anticipated to prevail into the beginning of next week.
... Arena to pt Reyes 10-60 nm
Small Craft Advisory...pt Reyes to Pigeon pt 10-60 nm
Small Craft Advisory...Pigeon pt to pt pinos 10-60 nm
Small Craft Advisory...pt pinos to pt Piedras Blancas 10-60 nm
Public forecast: Sims
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