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Area forecast discussion 
National Weather Service San Francisco Bay area
1005 PM PST Tuesday Nov 24 2015 wake of today's frontal passage...scattered showers
will be possible tonight through Wednesday morning as an upper
level pushes inland to our northeast. Given the cold air
mass...light snow will be possible in the highest peaks across the
region tonight into Wednesday morning. Dry weather conditions
return for Thanksgiving day...along with continue cooler than
average temperatures that will persist into the upcoming weekend.

&& of 08:33 PM PST Tuesday...after an active
weather day around the Bay area the evening has proved to be a
little more quiet. A cold front traversed the region today
bringing periods of rain and gusty winds. 24 hour rainfall totals
ranged from just a few hundredths to three quarters of an inch.
The highest rainfall totals were generally near the
coast...especially Santa Cruz with 0.78 inches.

Behind the front showers continue to move from the northwest to southeast
across parts of the Bay area. More notably are the temperature
drops Post frontal. A few peaks around the region are already
sitting at 32 degrees with several other locations colder than 40
degrees. In addition...profilers across the North Bay put snow
levels 2900-3200 feet.

For the rest of tonight...solid cold advection will continue keep
the region chilly over night with snow levels right around 3000
feet. As far as precipitation GOES...latest hi-res short term models
bring another round of precipitation overnight into early
Wednesday...specifically 08-14z time period. The precipitation will
likely be tied to the trough axis associated with the upper low
that is forecast to move overhead tonight. As always...the tricky
part with these set ups is...does the cold air line up with the
precip? Well...for tonight...the cold air is already in place so
that is in the plus column. Looking up stream (echoes on Eureka/S
radar) and hi-res model output definitely increases conf for
precipitation and cold air lining up tonight. Therefore...snow is looking
more likely with the best chance higher parts of Santa Cruz
mts/East Bay hills and any spots above 3000 feet in Monterey/San
Benito counties. Snow accumulations will be a light coating up to
poss 4 inches. Below 3000 feet...a cold damp night is in store. A
few showers may be lingering for the early portion of the
Wednesday commute. Another heads up for the overnight period will
be patchy black ice. Given today/S rain and poss rain
overnight...any shelter spots or side roads in the hills may see
some patchy black ice. Use caution traveling tonight and tomorrow

Dry conditions return Wednesday afternoon into Thursday...but
temperatures remain cold. Will have to watch overnight low the
next few nights...but they do not appear to be cold enough to
warrant a freeze warning.


Previous of 03:01 PM PST Tuesday...temperatures
tonight will turn colder as well with widespread 30s and 40s
expected. Showers will likely come to an end Wednesday morning
over the San Francisco Bay area...lingering through early
afternoon over the central coast as the upper level low shifts
inland. This will result in dry weather conditions over the entire
region for Thanksgiving day. Daytime temperatures will likely only
warm into the 50s for most locations through the remainder of the
weak as the broad middle/upper level trough remains stretched over
the region. Overnight temperatures will also fall into the 30s for
most locations Thursday morning through Saturday morning. Areas
closer to the coast should remain 40s...exception would be around
the Monterey Bay may also see low temperatures in the upper 30s.

The forecast models continue to show the potential for a weak upper
level low approaching the Southern California coast by Saturday.
This could bring some light precipitation to the central coast...yet
confidence remains low at this time. Heading into early next
week...the models continue to differ yet the GFS/Canadian both show
wet weather conditions returning back to the region. Meanwhile...the
European model (ecmwf) however is dry with the 12z run...while the previous 00z model
run was closer to the GFS/Canadian. As a result...will keep a
mention of precipitation for Monday and Tuesday of next week at this

&& of 10:02 PM PST Tuesday...showers will continue to
develop in the colder unstable northwest wind pattern over the area
tonight and early Wednesday morning. Model forecasts still leaning
toward steeper middle level temperature lapse rates over the north and East
Bay areas tonight and Wednesday morning which may cause isolated

Vicinity of ksfo...showers late tonight and Wednesday morning. Drier
by early Wednesday afternoon. VFR/MVFR.

Ksfo bridge approach...similar to ksfo.

Monterey Bay area terminals...VFR/MVFR. Showers and MVFR ceilings late
tonight/Wednesday morning.

&& of 9:23 PM PST Tuesday...a cold unstable air mass
associated with a low over northern California will cause
additional showers to develop overnight into Wednesday morning.
Winds have abated somewhat this evening but still could become
gusty at times from the northwest into Wednesday. Winds will
slowly diminish late on Wednesday.


Mtr watches/warnings/advisories...
... Reyes to Pigeon pt 0-10 nm
Small Craft Advisory...Pigeon pt to pt pinos 0-10 nm
Small Craft pinos to pt Piedras Blancas 0-10 nm
Small Craft Arena to pt Reyes 0-10 nm
Small Craft Arena to Pigeon pt 10-60 nm
Small Craft Advisory...Pigeon pt to pt Piedras Blancas 10-60 nm
Small Craft Advisory...rough bar advisory for sf bar until 3 am
Small Craft Advisory...mry Bay until 3 am



Public forecast: mm
aviation/marine: canepa

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