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Area forecast discussion 
National Weather Service San Francisco Bay area
323 am PDT Tuesday Jun 30 2015

Synopsis...a significant warming trend will continue across inland
portions of the region through Wednesday as high pressure builds
over the western United States. Moisture will also make its way
torward our area for wedensday into thursdy which could also lead
to a few showers and thunderstorms.

&&

Discussion...as of 3:15 am PDT Tuesday...moderately northerly
gradient along with a compressed marine layer (currently at 500
feet) has lead to generally clear clear conditions to this point across
our area this morning. Temperatures are mostly in the upper 50s to upper
60s with some spots more than 5 degrees ahead of yesterday.

All signs continue to point to very warm readings across our area
today and tomorrow particularly for inland spots due to a building
ridge of high pressure. 850 mb readings are forecast to increase 1
to 2 c while 500 mb heights increase a dm. Thermal trough is not
forecast to migrate offshore so highs will range from middle 60s to
middle 70s for most coastal spots up to the 90s and 100 to 110 range
for spots well inland. Will continue to highlight the very warm
readings in the Special Weather Statement. Please see the climate section below for the
list of current records.

Outside of the temperatures the other area of concern centers
around potential convection for Wednesday into Thursday due to a
possible easterly wave and moisture advecting in from the south.
Previous run of the NAM was very bullish with potential showers
and thunderstorms with the European model (ecmwf) keeping almost all of the
convection to our east. GFS ended up taking more a middle of the
Road approach with some showers indicated in our County Warning Area with precipitable water
values forecast to near 1.5 inches. Decided to add showers and
thunderstorms to a portion of our area especially for higher
elevation spots. Definitely Worth noting that this is far from
certain especially in light of the wide variety of solutions.

Highs will trend cooler the remainder of the week as the ridge
slightly weakens and heads to the east. Temperatures will continue to
have a typical wide Summer time range with 60s and 70s at the
coast while 80s to middle 90s remain inland.

&&

Aviation...as of 10:45 PM PDT Monday...stratus has been slow to
develop tonight. Marine layer has compressed to near 1000 feet and
northerly gradient has increased due to surface high pressure
over Oregon. Latest forecast has trimmed back the stratus in the
sfo Bay area but still expecting IFR ceilings at sfo and the approach
by 12z.

Vicinity of ksfo...IFR after 12z clearing by 17z.

Ksfo bridge approach...same as sfo.

Monterey Bay area terminals...IFR after 09-10z with local drizzle.
Early clearing of around 17z.

&&

Marine...as of 3:15 am PDT Tuesday...gusty northerly winds will
linger today as high pressure remains off the West Coast. Winds
will decrease Wednesday through Friday as a trough inland shifts
to the coast. A weak disturbance will move through the region on
Thursday bringing a chance of showers and thunderstorms to the
region.

&&

Climate...record highs for June 30 and July 1 for selected
locations.

Sf Bay area.................June 30............July 1
Kentfield..................106/1972...........103/1996
San Rafael..................98/1999............99/1991
Napa.......................105/1972...........103/1972
San Francisco...............93/1996............92/1991
sfo Airport.................92/1996............99/1985
Oakland downtown............90/1972............92/1984
Oakland Airport.............90/1950............90/1985
Richmond....................91/1996............97/1985
Livermore..................112/1972...........110/1950
Mountain View...............91/1972............97/1985
San Jose...................100/1996...........102/1985
Gilroy......................98/1999...........108/1972

Monterey Bay area............June 30............July 1
Monterey....................89/1996............96/1985
Santa Cruz..................98/1996............99/1970
Salinas.....................94/1996............85/1996
Salinas Airport.............97/1996............88/1991
King City..................109/1950...........105/1985



&&

Mtr watches/warnings/advisories...
... Arena to pt Reyes 0-10 nm
Small Craft Advisory...pt Arena to Pigeon pt 10-60 nm
Small Craft Advisory...pt pinos to pt Piedras Blancas 0-10 nm until 9 am
Small Craft Advisory...Pigeon pt to pt Piedras Blancas 10-60 nm until 9 am
Small Craft Advisory...sf Bay from noon

&&

$$

Public forecast: Bell
aviation: west pi
marine: mm
climate: Bell



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