Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Francisco Bay area
1043 PM PDT Thursday Jul 24 2014
Synopsis...a warming trend will continue across the region with
the warmest conditions expected Friday afternoon. Above average
temperatures will persist through the remainder of the
weekend...especially inland...as high pressure continues to
dominate the weather pattern.
Discussion...as of 8:54 PM PDT Thursday...the last few satellite
images of the day show clear skies across the state with only a
swath of high clouds steaming across the central coast and into
Nevada. As anticipated today's temperatures rose significantly
over yesterday's highs with inland temperatures reaching into the
middle 80s and 90s. Warmest inland locations topped out around 100
with our Hot Spot today (pinnacles) reaching 103 this afternoon. A
different story was had along the immediate coast as temperatures
actually dropped a few degrees from yesterday as a result of a
persistent onshore flow.
Models indicate a steady rise of temperatures aloft with 850mb
temperatures expected to reach 24 degrees c by Friday afternoon. Temperatures
should then increase approx 2 degrees per day through Monday.
Along with the warmer airmass aloft...a thermal trough at the
surface will push to the coast Friday ultimately shutting off the
onshore flow at the coast and allowing the warming trend to extend
to the beaches. While inland areas will see the warmest temperatures
with most inland locations reaching well into the 90s and low
100s. Coastal and Bay regions will see temperatures in the 80s.
From previous discussion...expecting temperatures to cool
slightly for the remainder of the weekend as onshore flow
increases...yet remain above seasonal averages. Will continue to
have to watch for possible middle-level moisture that may once again
advect along the back side of the ridge over the Desert Southwest
into our area late in the weekend. Could see an increase in middle
and high level clouds with this...yet not too concerned of any
convection at this point. Something Worth keeping an eye on in the
By early next week...persistent onshore flow will likely have
cooled sea surface temperatures back to normal values and allow
for a more established marine layer to develop. Thus...overnight
and early morning low clouds will likely return and keep
conditions coolest along the coast. With the ridge aloft...inland
areas will continue at or above normal values for the end of July
and maintain dry weather conditions.
Aviation...as of 10:30 PM PDT Thursday...gradients trending more
offshore today and skies are clear over the area. VFR is expected
through Friday in the sfo Bay area but cannot rule out patchy low
clouds in mry Bay late.
Vicinity of ksfo...VFR through Friday.
Ksfo bridge approach...similar to ksfo.
Monterey Bay area terminals...IFR ceilings redeveloping and spreading
into mry and sns after 12z. Confidence is low as it could stay
clear all night.
Marine...as of 10:00 PM PDT Thursday...a 1030 mb high is centered 800 miles west of Cape Mendocino. The
high will weaken on Friday and the thermal trough will shift to
the coast resulting in decreasing winds for all areas Friday
through Monday except the northern outer waters.
... Arena to pt Reyes 10-60 nm
Small Craft Advisory...pt Reyes to Pigeon pt 10-60 nm
Small Craft Advisory...Pigeon pt to pt pinos 10-60 nm until 5 am
Small Craft Advisory...pt pinos to pt Piedras Blancas 10-60 nm until 5 am
Small Craft Advisory...pt Arena to pt Reyes 0-10 nm
Small Craft Advisory...pt pinos to pt Piedras Blancas 0-10 nm until 3 am
Public forecast: CW
aviation/marine: west pi
Visit US at weather.Gov/sanfrancisco
Follow US on facebook, twitter, and youtube at: