National Weather Service Raw Text Product

Displaying AFOS PIL: AFDMTR Received: 2017-08-12 18:07 UTC


995 
FXUS66 KMTR 121807
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco Bay Area
1107 AM PDT Sat Aug 12 2017

.SYNOPSIS...Low pressure off the California coast will maintain
mild temperatures through the period with the normal night and
morning coastal stratus. 

&&

.DISCUSSION...as of 8:48 AM PDT Saturday...Widespread stratus 
will persist along the coast and across inland valleys this 
morning. Clearing over inland areas will be similar to yesterday 
with most locations clearing to the coast by 17z-18z this morning.
A slightly stronger onshore gradient from SFO-SAC (2.3 mb 
compared to 1.8 mb 24 hours ago) will likely offset an earlier 
clearing time that we likely would have seen with the slightly 
more compressed marine layer and a stronger northerly gradient 
from ACV-SFO (2.5 mb compared to 1.8 mb 24 hours ago). 

Afternoon high temperatures will be similar to what we saw
yesterday. Low clouds along the coast will prevail maintaining 60s
along the coast. 70s expected around the bays with 80s inland. 90s
are expected over the warmest inland valley locations with a few
100s sprinkles across the southern Monterey County region.

Little change is expected Sunday as high pressure remains in 
control. By Monday an upper level trough will dig south over the
western U.S. injecting a cooler airmass across the region. Inland
temperatures are anticipated to cool 5 to 10 degrees while coastal
locations see only a few degrees of cooling. These cooler
temperatures will persist into Tuesday before the upper trough
shifts east and high pressure once again takes hold of the area. A
gradual warming trend is expected to begin Wednesday and continue
through the remainder of the end of the week as high pressure
builds over the Eastern Pacific.

&&

.AVIATION...As of 10:59 AM Saturday for 18Z TAF Package. Latest 
visible satellite imagery shows stubborn stratus in and around 
Monterey Bay/San Francisco Bay regions. IFR and LIFR dominate 
these areas at this time. The marine layer has deepened a few 
hundred feet over the past 6 hours, to around 1600-1700 ft, per 
the Fort Ord Profiler. VFR expected for all TAF terminals by 
1930z, albeit tricky for KOAK and KMRY. The overall weather 
pattern will remain unchanged over the next 24-36 hours for the 
most part, with the Bay Area in-between a trough to the north and 
ridge to the south. Expect the marine layer depth to remain around
1500 ft, perhaps even compress a little more. Not exactly sure 
how far inland the stratus will push tonight; skeptical whether 
KSJC and KLVK will see cigs overnight. Afternoon seabreeze winds 
will pick up this afternoon and through the early evening hours. 

Vicinity of KSFO...MVFR/IFR will gradually transition back to VFR
conditions over the next hour or so, though hard to specify 
exactly when. Cigs return as early as 03z tonight. Moderate
onshore winds by this afternoon, sustained between 15-20 kt,
occasionally gusty.  

SFO Bridge Approach...Cigs over the bridge have cleared for the
most part. Expect full visuals by 19z, perhaps sooner.  

Monterey Bay Terminals...IFR cigs will prevail over KMRY through
1930z, at least. Some clearing is expect, but low confidence on
exact timing. VFR at KSNS through about 05z, before IFR cigs 
return, though could be sooner. Light to moderate westerly winds
this afternoon, between 10-15 kt. 

&&

.MARINE...as of 8:33 AM PDT Saturday...Moderate to occasionally 
strong north/northwest winds will prevail over the coastal waters 
through the weekend and into next week as high pressure builds off
the coast and interacts with thermal troughing inland.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tday...SCA...SF Bay from 3 PM
             SCA...Mry Bay from 3 PM
             SCA...Pigeon Pt to Pt Pinos 0-10 nm from 3 PM
             SCA...Pt Arena to Pt Reyes 0-10 nm
             SCA...Pt Arena to Pigeon Pt 10-60 nm
             SCA...Pt Reyes to Pigeon Pt 0-10 nm
             SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm
             SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm from 3 PM

&&

$$

PUBLIC FORECAST: CW
AVIATION: BAM
MARINE: BAM


Visit us at www.weather.gov/sanfrancisco

Follow us on Facebook, twitter, and youtube at:
www.Facebook.com/nwsbayarea
www.twitter.com/nwsbayarea
www.youtube.com/nwsbayarea