Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Francisco Bay area
339 am PDT sun may 24 2015
Synopsis...warmer weather is forecast today as high pressure
begins to build near the West Coast. Little change is then
expected through Tuesday. Temperatures are expected to climb above
normal for inland areas during the second half of the week.
However...coastal areas will remain seasonably cool as onshore
Discussion...as of 3:35 am PDT Sunday...a slightly drier airmass
has made its way into the boundary layer since yesterday as an
upper ridge offshore edges in along the West Coast.
Consequently...low cloud cover is much less extensive early this
morning compared to the past few mornings and the expectation is
that most of our forecast area will experience more sun today.
Afternoon highs today are forecast to be...on average...about five
degrees warmer than yesterday.
Not much change is expected going into Monday and Tuesday. The
upper ridge will remain just offshore as an upper low drops south
into the Pacific northwest. Temperatures are expected to hold steady or cool slightly.
The upper ridge is forecast to finally shift eastward beginning
midweek...and be centered over California by late Thursday and Friday.
This will result in a warming trend during the second half of the
week. Most of that warming expected to occur inland where high
temperatures are forecast to climb above normal for the first time
in nearly four weeks. Locations such as Santa Rosa and Livermore
are forecast to warm above 80 by Thursday...the first time those
locations have seen 80 since may 1st and 2nd. Coastal areas will
remain relatively cool due to persistent onshore flow. The bias-
corrected high temperature gridded forecasts appear to be too cool
for inland areas during the second half of the week...likely the
result of our recent prolonged cool spell. So have forecast inland
highs above the bias-corrected values during the second half of
Slight cooling is expected next weekend as the upper ridge shifts
off to our east. No rainfall is expected in the next 7-10 days.
Aviation...as of 9:30 PM PDT Saturday...a middle-upper level low
pressure area over the Central Valley will move S-southeast during the
period. Low clouds will continue to redevelop over the area
overnight. MVFR ceilings localized IFR possible.
Vicinity of ksfo...MVFR ceilings. Low clouds forecast to clear by 20z
Sunday. Forecast confidence low to moderate.
Ksfo bridge approach...similar to ksfo.
Monterey Bay area terminals...MVFR ceilings during the period. Partial
clearing possible Sunday.
Marine...as of 2:53 am PDT Sunday...gusty northwest winds will continue
into Sunday producing fresh seas with short period swells. Winds
may ease slightly on Memorial Day but northwest winds will continue
through much 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 until 9 am
Small Craft Advisory...pt pinos to pt Piedras Blancas 10-60 nm until 9 am
Small Craft Advisory...pt Arena to pt Reyes 0-10 nm
Small Craft Advisory...pt Reyes to Pigeon pt 0-10 nm until 3 am
Small Craft Advisory...sf Bay north of the Bay Bridge from 3 PM
Public forecast: dykema
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