Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
FXUS66 KMTR 252021
Area Forecast Discussion
National Weather Service San Francisco Bay Area
121 PM PDT Tue Apr 25 2017
.SYNOPSIS...Seasonably cool temperatures will persist into
Wednesday as a weak system passes inland to the north. This will
result in a slight chance of light precipitation, mainly from the
Santa Cruz Mountains northward into Wednesday. A warming and
drying trend will then get underway beginning Thursday and likely
continuing into the upcoming weekend as high pressure builds over
the eastern Pacific. Breezy northerly winds are also possible from
Thursday into Friday, especially in the hills.
.DISCUSSION...as of 01:20 PM PDT Tuesday...Deep moisture aloft
continues to advect inland across the region this afternoon and
has resulted in widespread mid/high level cloudiness. All of this
is in advance of a weak mid/upper level trough that will push
inland into the Pacific Northwest late tonight into Wednesday.
This system may bring some very light precipitation to the
northern portion of our region, mainly from the Santa Cruz
Mountains northward early Wednesday morning. Cannot rule out some
lingering showers into the early afternoon from the East Bay Hills
down into the Santa Lucia Mountains, yet chances for widespread
measurable rainfall remain minimal as this system lacks needed
mid/upper level support as it pushes inland to our north. With
this passing system, temperatures will be seasonably cool and
temperatures will range from the lower 06s coast to middle 60s
inland through Wednesday. Some of the warmer, interior locations
of the Central Coast may warm into the lower 70s.
A warming trend will then get underway by Thursday as dry conditions
return along with mostly sunny skies. As a stronger mid/upper level
low drops southward out of Canada into the Rockies and high pressure
develops offshore late in the week, temperatures will warm into the
70s inland. In addition, breezy to locally gusty winds will develop
due to the tightening pressure gradient from Thursday into Friday.
Further warming of the air mass aloft will result in lower 80s
during the afternoon hours this weekend while onshore winds near the
coast keep temperatures in the 60s to 70s.
Temperatures moderate slightly by early next week as the mid/upper
level ridge weakens as a system pushes inland into the Pacific
Northwest. With that said, the main storm track will remain well
north of the region and dry weather conditions are likely into the
beginning of May.
.AVIATION...as of 10:19 AM PDT Tuesday...Mid and high level clouds
continue to stream in from the north ahead of the next system.
Expecting VFR today with breezy conditions. Cigs will gradually
lower overnight with -ra poss at KSTS early Wed, but will only do
VCSH for KOAK and KSFO.
Vicinity of KSFO...Little change from previous forecast. VFR
through today. MVFR cigs develop tonight/early Wednesday. A
passing shower poss early Wednesday.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...VFR. Afternoon sea breeze. Lower cigs
return tonight with MVFR category.
.MARINE...as of 10:17 AM PDT Tuesday...Moderate to locally strong
northerly winds will prevail as high pressure remains anchored off
the coast. The strongest winds will likely occur monterey bay
southward along the immediate coast. Winds and seas will increase
over all coastal waters on Wednesday as high pressure
.Tngt...SCA...Mry Bay until 9 PM
SCA...Pigeon Pt to Pt Pinos 0-10 nm until 9 PM
SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm
PUBLIC FORECAST: RGass
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