Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
FXUS66 KMTR 281056
Area Forecast Discussion
National Weather Service San Francisco Bay Area
356 AM PDT SAT MAY 28 2016
.SYNOPSIS...A dry and seasonably warm Memorial Day weekend is
forecast for the Bay Area. The trend will continue at least
through the middle of next week with no significant cooling
expected until late in the week at the earliest.
.DISCUSSION...as of 3:56 AM PDT Saturday...The coast is clear of
low clouds for the most part with just a few patches around
Monterey Bay and the Big Sur coast. Otherwise some high clouds are
over the Bay Area but will have little impact on the sensible
weather. The northerly gradient is still around 8 mb down the
coast and producing gusty north winds over the coastal waters. The
associated upwelling has allowed the sst to drop as low as 49-50
degrees at the coastal buoys. Meanwhile north winds are dropping
down the Sacramento Valley and showing up at places like Santa
Rosa and Travis afb but nothing too strong. Up in the hills Mt
Diablo is now reporting north winds 30 mph with gusts to 40 mph.
These winds are acting to dry the boundary layer and setting the
stage for a warm to hot day inland, as well as keeping any coastal
cloud formation in check. Upshot is to expect a mostly sunny and
warm Saturday with inland highs well in the 80s with even some
lower 90s for the warmest interior locations of the far east bay
and places like Pinnacles NP.
The north winds will collapse by midday and there is still enough
of an onshore component to allow an afternoon seabreeze through
the Golden Gate, that may stretch into the West Delta by this
evening. NAM model still suggests that low clouds will reform
tonight and along with onshore winds will bring some subtle
cooling for Sunday, mainly near the bay with only a few degrees of
change farther inland.
High pressure builds aloft Memorial Day into Tuesday, especially
over northern California with a thermal trough along the coast.
Gradients will be weak but still expect an overall warming trend
with more 80s and 90s for Monday and Tuesday with little marine
influence for the Bay Area. The way the ridge is setting up the
marine layer may stay more intact from Monterey Bay southward
early in the week.
Not surprisingly longer range models are now keeping the warm
ridge in place for much of next week. The 00z ecmwf keeps the
ridge in place most of the week with 850 mb temps around 22
Celsius. In fact the ecmwf solution more or less blocks the next
incoming upper trough with 850 mb temps approaching 25 Celsius or
warmer by late in the week, suggesting if anything the long range
forecast may need to be trended warmer. Not seeing any precip in
the long range forecast. Sometimes climatology is hard to beat
and with the calendar ready to turn to June it appears summer like
weather is here.
.AVIATION...as of 10:40 PM PDT Friday...VFR conditions persist
region wide this evening with diminishing wind speeds. A northwest
gradient over the region and drier air aloft will likely result in
continued VFR conditions for all of the region overnight and into
Vicinity of KSFO...VFR through the period. West-northwest winds
generally below 12 KT through the night becoming light and
variable early Saturday morning. West-northwest winds increase
once again Saturday afternoon. High confidence.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...VFR through the period. Light onshore
winds will likely persist through the night. Return of stratus
deck appears more unlikely overnight, yet may see FEW/SCT low
clouds develop briefly early Saturday morning. Moderate to high
.MARINE...as of 03:37 AM PDT Saturday...Gusty northwest winds will
continue over the coastal waters through the weekend.
additionally... steep fresh swell from these winds will generate
hazardous seas. the gusty winds and fresh seas gradually subside
early next week. meanwhile... a building southerly swell is
anticipated to arrive early next week.
.Tday...SCA...Pt Arena to Pt Reyes 0-10 nm
SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm
SCA...Pt Reyes to Pigeon Pt 0-10 nm until 9 AM
SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm until 9 AM
PUBLIC FORECAST: RWW
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