Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Francisco Bay area
856 am PDT Wednesday Oct 7 2015
Synopsis...dry weather conditions along with a gradual warming
trend will persist over the district through late in the week as
high pressure builds over the state. Temperatures will hold steady
through the weekend as the ridge flattens and zonal flow develops
Discussion...as of 8:56 am PDT Wednesday...early morning visible
satellite imagery shows low clouds covering a large portion of the
San Francisco Bay area this morning...with only patchy fog around
the Monterey Bay and Salinas valley. Expect these low clouds to
clear by middle to late morning...with afternoon temperatures warming
to similar values as on Tuesday with upper 60s and 70s near the
coast...to the 80s to near 90 inland.
Meanwhile...an upper level ridge continues to build over the
West Coast with a cut-off low now centered over Arizona. As this
ridge builds...warmer temperatures are expected across our area
through Friday. By Friday...temperatures will be 5 to 10 degrees
above seasonal averages with highs ranging from 70s to near 80
near the coast to the middle 90s inland.
The ridge will begin to flatten during the weekend as the upper
level flow becomes more zonal. This should hold temperatures steady
through early next week. Late in the weekend the cut-off low over
Arizona is prognosticated retrograde westward through northern Mexico and
off of the Baja California California coast. Early next week the medium
range models take the closed upper level low northward towards
Southern California. This could bring some middle-level moisture
towards the district by Tuesday or Wednesday which could spread
shower chances across the southern portions of the district by
middle of next week.
Aviation...as of 4:57 am PDT Wednesday...the current infrared
satellite fog product is showing some patchy low clouds around the
forecast area this morning. San Francisco Bay area observation are
reporting MVFR ceilings and Monterey is presently bouncing between scattered
and bkn006. According to The Fort Ord profiler there really isn't
a true marine layer...so most of the low clouds are most likely
shallow radiation type clouds that should burn off quickly this
Vicinity of ksfo...MVFR ceilings broken-ovc015 are expected to burn off
fairly quickly this morning with an expected burnoff by 1730z. The
wild card is the low sun angle but 1730z should be a safe bet. The
sea breeze is anticipated to reach 17 knots this afternoon.
Confidence is moderate.
Ksfo bridge approach...similar to ksfo.
Monterey Bay area terminals...ceilings are expected to bounce between
sct006 and bkn006 through 1630z this morning. Keep in mind that
just a little bit of marine air this time of year can quickly
saturate the atmosphere resulting in a period of dense fog...the
best possibility of these conditions will be between 1400 and
1600z this morning.
Confidence is moderate.
Marine...as of 8:39 am PDT Wednesday...light to moderate
northerly flow will persist over the coastal waters as weak high
pressure remains off the coast.Gentle seas are also expected to
persist into the weekend with a mixed swell. A moderate period
west southwesterly swell generated by hurricane oho will enter the
waters beginning roughly Friday.
Public forecast: Sims
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