Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
FXUS66 KMTR 300526
Area Forecast Discussion
National Weather Service San Francisco Bay Area
1026 PM PDT SUN MAY 29 2016
.SYNOPSIS...A deep marine layer and light onshore flow will
maintain low clouds along the coast tonight...portions of the
inland valleys will also see low clouds overnight. A warming
trend will begin Memorial Day with warm temperatures expected through
the end of the week...the coast is anticipated to remain cool.
.Discussion...As of 9:17 PM PDT Sunday...Low clouds are in place
along the coast with the Fort Ord profiler showing the depth of
the marine layer reaching 2000 feet. Halfmoon Bay Airport is
currently reporting cigs at 300 feet and Monterey Airport is
reporting cigs at 800 feet...suggesting a thick cloud layer.
Gentle onshore flow should push these clouds into the inland
The current satellite water vapour image is showing high pressure
building over the Eastern Pacific while a low pressure system
pushes into the desert south west. The 1200Z ECMWF and 0000Z GFS20
have initialized well with the current synoptic pattern and remain
in good agreement through at least next weekend. Over the next few
days both models build a ridge of high pressure over the Eastern
Pacific and California. This will result in a warming
trend...primarily for the inland areas and will also maintain dry
weather through at least Friday.
Both models are in pretty good agreement with an upper level low
approaching southern california towards the end of the work week.
If this low actually materializes it will begin to impact southern
and central California on Saturday. The 1800Z GFS20 is showing
some upper level moisture and elevated instability over the Big
Sur Coast on Saturday and Sunday. These ingredients could result
in elevated thunderstorms so we will need to keep a good eye on
this developing weather scenario. This is my first forecast shift
in a few days so I`m reluctant to add thunder to next weekends
forecast. However...if the models continue to show this scenariowe
may need to add them in.
.AVIATION...as of 10:30 PM PDT Sunday...Coastal clouds are
starting to spread into SFO Bay so there is a better chance for
cigs in the SFO Bay Area tonight. Marine layer is around 2000 feet
so burnoff should be around 18z.
Vicinity of KSFO...MVFR after 08z.
SFO Bridge Approach...Same as KSFO.
Monterey Bay Terminals...IFR through 17-18z.
.MARINE...as of 10:30 PM PDT Sunday...HIGH PRESSURE COVERS THE
EASTERN PACIFIC WITH A RIDGE EXTENDING INTO THE PACIFIC NORTHWEST.
THIS IS BRINGING GUSTY NORTHWEST WINDS OVER THE OUTER WATERS. THE
RIDGE WILL WEAKEN ON MONDAY ALLOWING FOR WINDS TO DECREASE. A
BUILDING SOUTHERLY SWELL IS ANTICIPATED TO ARRIVE EARLY NEXT WEEK.
.Tngt...SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...Pt Arena to Pt Reyes 0-10 nm until 11 PM
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm until 2 AM
PUBLIC FORECAST: Larry
AVIATION: W Pi
MARINE: W Pi
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