Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS66 KMTR 212002
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco Bay Area
102 PM PDT Sat Oct 21 2017

.SYNOPSIS...The slight warming trend that got underway across region
today will continue through the first part of the upcoming workweek
as temperatures warm well above seasonal averages on Monday and
Tuesday. Dry weather conditions are also likely to persist with a
slight cooling trend possible late next week.

&&

.DISCUSSION...as of 01:01 PM PDT Saturday...Temperatures are
slightly warmer compared to this time yesterday under mostly sunny
conditions as high pressure builds in from the south. There is
the potential for some low clouds to redevelop overnight near the
coast and spread locally inland into the Sonoma Valley and around
the San Francisco Bay that will persist through Sunday morning.
Otherwise, look for the warming trend to resume by Sunday
afternoon with most locations warming into the lower 70s at the
coast to upper 70s inland.

The ridge of high pressure will then strengthen and build further
north over the region and result in a warming, drying air mass aloft
early in the upcoming workweek. With this, expecting afternoon
temperatures to warm into the upper 70s to lower 80s even at the
coast with widespread 80s and even a few lower 90s for inland areas
on Monday. Tuesday currently appears to be the warmest with
temperatures in the 80s at the coast to lower 90s inland. A few of
the warmest inland areas may even warm into the middle 90s as weak
offshore flow develops. With that said, overnight conditions will
cool into the 50s during the overnight/early morning hours early
next week to provide relief from the daytime heat. The exception
will be in the hills where overnight lows may only cool into the
60s.

A mid/upper level trough is then forecast to drop southward into the
Great Basin and Central Plains by Wednesday which will push the
ridge of high pressure back out over the eastern Pacific. This
should allow conditions to cool slightly Wednesday and through late
week. However, the extended forecast continues to call for above
average temperatures to persist along with ongoing dry weather
conditions.

&&

.AVIATION...As of 10:40 AM PDT Saturday...VFR will prevail through
TAF period with generally light variable AM winds and light
onshore breeze PM winds. System impacting PacNW will spread some
high clouds into the area through the day.

Vicinity of KSFO...VFR. West winds around 11 kt after 21Z.

SFO Bridge Approach...Similar to KSFO.

Monterey Bay Terminals...VFR.

&&

.FIRE WEATHER...As of 5:30 AM PDT Saturday...Gradual warming
trend starts today with light northerly winds. This trend
continues into tomorrow with winds turning more to the northeast
with continued warming and drying. Another round of gusty offshore
winds is forecast for the Napa hills Sunday night into Monday
morning. Recent rain has helped but will need to watch the Sunday
night into Monday morning wind event closely. Long range trends
suggest warm to hot afternoons and very dry conditions with
periods of offshore winds for much of next week.

There is also concern about a potential northerly wind event for
the North and East Bay Hills late Thursday into Friday.

&&

.MARINE...as of 10:33 AM PDT Saturday...Light split flow winds
today with increasing northerly flow late in the weekend. A long
period northwest swell will continue to taper down through the
day. Hazardous conditions from squared seas will exist in most
offshore areas today.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tngt...SCA...Pt Arena to Pt Reyes 0-10 nm until 5 PM
             SCA...Pt Reyes to Pigeon Pt 0-10 nm until 5 PM
             SCA...Pigeon Pt to Pt Pinos 0-10 nm until 5 PM
             SCA...Pt Arena to Pigeon Pt 10-60 nm
             SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm
             SCA...Rough Bar Advisory for SF Bar until 3 PM
             SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm until 3 AM

&&

$$

PUBLIC FORECAST: RGass
AVIATION: DRP
MARINE: DRP
FIRE WEATHER: Bell

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


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.