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Area forecast discussion 
National Weather Service San Francisco Bay area
1117 PM PDT Thursday Jul 28 2016

Synopsis...smokey skies and very warm and dry conditions will
persist inland through Friday. Meanwhile, at the coast smokey
skies and cool conditions will continue through the weekend. A
region- wide cooling trend remains on track for the upcoming
weekend.

&&

Discussion...as of 8:30 PM PDT Thursday...plenty of smoke is
being reported to US via social media this evening as the
soberanes fire continues to burn. We even got a report via
facebook of smoke in Yosemite. The current visible satellite
image is showing the smoke pushing west near the surface into
interior Monterey and San Benito counties, while southerly winds
aloft are pushing the smoke north into the Bay area.

Stratus has moved into the Monterey area for the night as the
marine layer remains around 1200 feet deep this evening. The
marine layer will provide cool temperatures and moist conditions
for lower elevations around the area. However, the 0000z koak
sounding continues to show a temperature inversion above 1500
feet of around 85 degrees. This warm temperature inversion will
maintain warm dry conditions overnight for the higher elevations
around the area.

The 1200z European model (ecmwf) and 1800z gfs20 have initialized well with the
current synoptic weather pattern and remain in good agreement
through the middle of next week. Both models maintain a ridge of
high pressure centered over the Desert Southwest tomorrow. However
a low pressure system pushing into the Pacific northwest begins to
offset the Desert Southwest high, initiating a cooling trend for
our area beginning Saturday and persisting into the middle of
next week. The current forecast package handles this cooling
trend well and no updates are needed at this time.

One trend that we need to keep an eye on is the direction and
magnitude of the surface wind through about 10,000 feet. The
winds within this layer dictate the direction that the soberanes
fire smoke will move. It currently looks like winds within this
layer will become more southerly on Friday which will influence
the smoke to push in more of a northern direction than observed
today. Therefore have adjusted the weather grid to spread the
smoke northward into the San Jose and southern portions of the
East Bay.

&&

Aviation...as of 11:00 PM PDT Thursday...stratus along the coast
is beginning to move inland over coastal valley under a 1000 foot
marine layer. Smoke from the soberanes fire continues to impact
the region tonight however it is rising above the inversion and is
not affecting the terminal vsbys. Conditions will be similar to
last night with light winds and low cigs over select terminals by
morning.

Vicinity of ksfo...VFR conditions expected through the forecast
period over ksfo. On the other side of the Bay koak will see cigs
return early Friday morning around 11z with clearing around 17z.

Sfo bridge approach...areas of low clouds are expected to affect
the approach after 12z Friday morning. Low clouds will scatter
out around 17z. Light winds.

Monterey Bay terminals...smoke from the soberanes fire will
continue to linger aloft over the Monterey Bay area tonight. LIFR
to vlifr cigs/vsbys anticipated to persist through the night. Cigs
anticipated to lift around 16z-17z Friday morning. Light winds.

&&

Fire weather...as of 3:55 am PDT Thursday...smoke is still
lingering around the fire district today as transport winds remain
relatively light with varying directions through the vertical.
Tomorrow smoke transport winds in the Monterey area look to become
more from the south direction. This may bring more smoke to
Salinas and Monterey as well as into the Santa Clara Valley. The
marine layer mixed out a bit today but according to The Fort Ord
profiler it is holding steady at 800 to 1000 feet. Low clouds are
anticipated to return to Monterey Airport by around 0300z this
evening.

&&

Marine...as of 11:00 PM PDT Thursday...high pressure over the
eastern Pacific coupled with a thermal trough along the coast
will maintain light to moderate northwesterly winds across the
coastal waters. Strongest winds will remain over the northern
outer waters and north of the Bay Bridge. A mixed swell will
continue in the coastal waters.

&&

Mtr watches/warnings/advisories...
... Bay until 3 am
Small Craft Advisory...pt Arena to Pigeon pt 10-60 nm until 3 am

&&

$$

Public forecast: Larry
aviation: CW
marine: CW
fire weather: Sims



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