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000 
FXUS66 KMTR 171141
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco Bay Area
441 AM PDT Thu Oct 17 2019

.SYNOPSIS...A weakening frontal boundary will continue to push 
through the Central Coast this morning with the potential for very 
light rain. Cooler, breezy conditions will develop in wake of the 
frontal passage this afternoon and continue through Saturday. A 
warming and drying trend will the commence through the upcoming 
weekend and into next week.

&&

.DISCUSSION...as of 03:11 AM PDT Thursday...A weakening frontal 
boundary continues to push across the region early this morning. 
As expected, rainfall amounts have be isolated to scattered at 
best with generally only a few hundredths of an inch for locations
that have receive measurable precipitation. Low and mid-level 
cloud cover and moist onshore flow associated with this frontal 
boundary has kept temperatures much warmer compared to 24 hours 
ago. Most locations are anywhere from a few to as much as 15 
degrees warmer (Napa County Airport) compared to this time 
yesterday. 

Lingering light precipitation will be possible over southern 
portions of the greater San Francisco Bay Area down through the 
Central Coast through around sunrise as the frontal boundary 
advances southward. Otherwise, look for mainly dry conditions region-
wide as best mid/upper level support will stay well to our north. In 
wake of the frontal passage, look for northwest winds to increase by 
this afternoon and become locally gusty at times along the coast and 
in the hills. Sky conditions will also begin to clear aside from 
some post-frontal cumulus which typically develops in the hills. 
Temperatures will also be slightly cooler this afternoon, especially 
in the hills and higher elevations where 50s and 60s will be common. 
More widespread 60s are likely near the coast with lower 70s 
possible in the interior valleys. Very little change is anticipated 
on Friday, however wind speeds will likely ease a bit. 

Another quick-moving weather system will clip the North Bay late 
Friday night into Saturday morning. This system may produce a brief 
period of light rain, yet most of the remainder of the region will 
remain dry. As this system exits the region, a brief period of dry 
offshore winds will be possible over the North Bay by late Sunday 
night into early Monday. However, these winds are not forecast to be 
strong. A subtle warming trend is also expected through the upcoming 
weekend as high pressure builds over the eastern Pacific.

Longer range models and ensemble guidance suggest that high 
pressure to the west will build over California during the second 
half of next week. This will likely result in a robust warming trend 
and periods of offshore flow. Dry conditions will also persist 
through the extended forecast period. Thus, will need to continue to 
monitor the potential for fire weather concerns.

&&

.AVIATION...as of 10:45 PM PDT Tuesday...Weak frontal passage
currently is bringing a spectrum of MVFR to IFR cigs across the
Bay Area. Clearing will be strongly dependent on the movement of
the front, but it should transition to VFR conditions from north 
to south through the morning hours. Breezy northwest winds will 
develop by midday, lasting through the afternoon.

Vicinity of KSFO...Borderline MVFR/IFR cigs for the morning hours,
becoming VFR by the late morning. Winds will be onshore,
increasing through the day with gusts approaching 25 kt in the
afternoon.

SFO Bridge Approach...Similar to KSFO.

Monterey Bay Terminals...IFR/MVFR cigs and/or vis due to frontal
cloud passage currently. Transition to VFR conditions around 
midday. Increasing, breezy onshore winds through the afternoon.

&&

.MARINE...as of 04:34 AM PDT Thursday...Moderate northwest winds
will continue over the waters through  Friday. A large, northwest
swell will arrive this afternoon with  the largest waves occurring
Thursday night and Friday. The  northwest swell will persist as
the dominant wave through the  weekend, waves will slowly reduce
from their peak heights but will remain at hazard levels for small
craft.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tday...High Surf Advisory...*CAZ006-505-509-529-530*
             SCA...Pigeon Pt to Pt Pinos 0-10 nm from 9 AM
             SCA...Pt Arena to Pt Reyes 0-10 nm
             SCA...Pt Reyes to Pigeon Pt 0-10 nm
             SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm
             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 from 11 AM
             SCA...Mry Bay from 11 AM
             SCA...SF Bay from 2 PM

&&

$$

PUBLIC FORECAST: RGass
AVIATION: DK
MARINE: DK

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