Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Francisco Bay area
253 PM PDT Sat Jul 23 2016
Synopsis...slightly cooler temperatures for the inland areas on
Sunday. Onshore flow and cool marine air will maintain cool
conditions near the coast. A second warming trend is anticipated
for the inland areas beginning on Tuesday.
Discussion...as of 2:53 PM PDT Saturday...mostly clear skies
continue across the forecast area this afternoon. The current
visible satellite image continues to show a well defined smoke
plume generated by the sobranes fire. This smoke plume has a south
southwesterly trajectory. Low clouds are passing over the coastal
waters and stratus is beginning to impact the immediate coast as
the afternoon sea breeze sets in.
The 1200z European model (ecmwf) and gfs20 have initialized well with the current
synoptic weather pattern and remain in good agreement through at
least next Friday. Both models maintain a dome of high pressure
over the forecast area today with a slight fall in heights on
Sunday, resulting in slightly cooler inland temperatures for
Sunday and Monday. Cool seasonal temperatures are expected to
persist along the coast. By Tuesday a Four Corners high sets up
bringing another round of warm weather to our forecast area which
will last through the end of next week.
Fire...as 9:30 am PDT...Saturday...high pressure persists over
California today and has compressed the marine layer to around
1000 feet deep this morning. The marine layer is expected to
remain compressed to at or below a 1000 feet tonight. In addition,
a temperature inversion is anticipated to set up overnight
maintaining warm overnight temperatures over areas of higher
terrain. Overnight temperatures at 2000 feet will be in the mid to
upper 70s with poor relative humidity recoveries.
Aviation...as of 10:57 am PDT Saturday...VFR conditions expected
to continue today with afternoon seabreeze winds to 20 kt. Coastal
stratus to spread locally inland by Sunday morning affecting most
Vicinity of ksfo..VFR. West winds 15g22 kt after 21z. MVFR cigs
after 12z Sunday.
Sfo bridge approach...similar to ksfo.
Monterey Bay terminals...VFR. IFR cigs after 07z.
Marine...as of 04:47 am PDT Saturday...moderate to strong
northwest winds will persist through the weekend as the surface
gradient strengthens. The strongest winds today will be along the
Big Sur coast where gale force gusts are possible. The strongest
winds will then shift to the northern outer waters later in the
weekend. Sea conditions will deteriorate as winds increase.
... Pt to pt pinos 0-10 nm until 3 am
Small Craft Advisory...pt Arena to pt Reyes 0-10 nm
Small Craft Advisory...pt Arena to Pigeon pt 10-60 nm
Small Craft Advisory...pt Reyes to Pigeon pt 0-10 nm
Small Craft Advisory...pt pinos to pt Piedras Blancas 0-10 nm
Small Craft Advisory...Pigeon pt to pt Piedras Blancas 10-60 nm
Small Craft Advisory...mry Bay until 10 PM
Public forecast: Larry
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