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Area forecast discussion 
National Weather Service San Francisco Bay area
1110 am PDT Tuesday Jul 28 2015

.Very warm to hot inland temperatures expected today through
Thursday of this week....

Synopsis...hot temperatures are expected to continue across
inland areas through midweek...with warm temperatures at the
coast as strong high pressure builds over the region. Temperatures
cool slightly late in the week along with increased monsoon
moisture approaching from the south.

&&

Discussion...as of 11:10 am PDT Tuesday...after some patchy
morning fog along the coast skies are mostly sunny around the area
this morning. Temperatures are warming up pretty quickly with
Livermore reporting a current temperature of 85 degrees...Hayward
reporting in at 75 and Morgan Hill at 85 degrees. The warm up is
on track with afternoon temperatures at many inland areas expected
to reach into the upper 90s to 105. Upper 70s to middle 80s are
anticipated along the coast. Overnight temperatures are expected
to be in the upper 50s to middle 60s at most locations.
However...overnight lows at elevations above 1500 feet will remain
in the middle to upper 70s.

The current satellite water vapour image is showing a ridge of
high pressure building over the eastern Pacific and California
coast with a low pressure system sliding east along the Canadian
and US border. Tropical depression 8 is also apparent at 16 north
and 128 west. The 1200z gfs40 and 0000z European model (ecmwf) have initialized
well and remain in good agreement into the weekend.

Both of the previously mentioned models build the ridge of high
pressure over California to about 591 dm Wednesday with 850mb
temperatures hovering around 24 to 25 degrees celsius Friday
morning. This translates into hot temperatures at the
surface...especially for the inland areas which are expected to
reach into the upper 90s to 105 on Wednesday before cooling a few
degrees on Thursday. Offshore winds will keep the coast fairly
warm to with afternoon highs expected to be in the upper 70s to
middle 80s.

Humid conditions will return to the area Friday as monsoon
moisture pushes into California. With really hot temperatures
leading into the arrival of the monsoon moisture there will be
some instability to support showers and isolated thunderstorms
Friday afternoon. The challenge is that the forecast models have
been bouncing around with the trajectory of the moisture and
location of instability. Therefore...with low confidence I am
planning on adding a threat of showers and isolated thunderstorms
to elevated areas around our County Warning Area. We will fine tune the threat as
we near Friday and the models zero in on a more defined solution.

&&

Aviation...as of 10:45 am PDT Tuesday... widespread VFR
conditions across the area today. Brief patchy fog posbl at or
before sunrise tomorrow morning.

Vicinity of ksfo...VFR conditions will prevail through the forecast
period. Afternoon winds increasing to 15 to 20 knots.

Ksfo bridge approach...similar to ksfo.

Monterey Bay area terminals...VFR conditions will prevail through
most of the forecast period. Brief patchy LIFR ceilings/visbys from
fog at or below sunrise Wednesday. Winds 12kt or less.

&&

Climate...here are record highs for Tuesday through Thursday
across our area along with the last year the record was recorded.

Sf Bay area..............7/28............7/29............7/30
Kentfield..............98/1934........105/1954........105/1977
San Rafael............104/1980........101/1977........102/1977
Napa..................107/1954........105/1954........103/1977
San Francisco..........84/1954.........83/1977.........85/1986
sfo....................88/1954.........91/1977.........97/1977
Oakland................76/1977.........98/1977.........95/1977
Oakland Airport........96/1954.........91/1977.........95/1977
Richmond...............88/1954.........82/1967.........80/1993
Livermore.............106/1980........108/1954........107/1979
Mountain View..........93/1954.........93/1977.........97/1977
San Jose..............100/1954.........95/1977........102/1995
Gilroy................101/1995........102/1980........106/1977

Monterey Bay area........7/28...........7/29.............7/30
Monterey...............85/1954........86/1977..........91/1977
Santa Cruz.............92/1947........88/1964.........102/1977
Salinas................92/1954........95/1977..........86/1995
Salinas Airport........84/1967........92/1977..........84/1977
King City..............99/1967.......105/1977.........106/1977

&&

Marine...as of 10:37 am PDT Tuesday...northwesterly winds will
gradually decrease through the day today as the pressure gradient
weakens. Locally gusty winds will linger over the northern outer
waters through this afternoon.

&&

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

&&

$$

Public forecast: Larry
aviation: drp
marine: mm
climate: Bell/Benjamin



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