NWS Forecast Area Discussion - San Francisco Area

FXUS66 KMTR 061157

Area Forecast Discussion
National Weather Service San Francisco Bay Area
457 AM PDT Wed Jul 6 2022

.SYNOPSIS...Without a well defined marine layer, a mix of low and
mid level clouds continue today. Morning coastal drizzle may be
possible in areas with lower clouds. A gradual warming and drying
trend begins by midweek, however, below normal temperatures
persist today through Friday for the afternoon highs. By Saturday,
the region warms more becoming near to slightly above normal
conditions through Monday.

&& of 04:07 AM PDT Wednesday...We`ve got another
morning of mixed clouds. Looking at the Fort Ord and Bodega Bay
profilers, we don`t see a well defined marine layer which is
allowing low and mid level clouds to move farther inland as
opposed to a defined and compressed marine layer that limits the
inland intrusion of coastal stratus. If you`re closer to the
coast and under low marine stratus, you could see a bit of drizzle
again this morning.

Once again, not expecting any major temperature swings for this
afternoon`s highs. For the past two days, max temps have generally been
within 1-3 degrees of each other, if not the same, for several of
our observation sites. The upper level low offshore from the
Pacific NW continues to linger and with not much change in the
atmospheric environment, expect similar conditions today as we`ve
been seeing: below normal highs with mid 60s to mid 70s closer to
the coast and mid 70s to mid 80s inland. We`ll see breezy
conditions this afternoon into evening, also similar to

Warming, especially across the interior, will become more
noticeable as we get towards the end of the week and into the
weekend. The airmass aloft will gradually warm as high pressure
strengthens over the desert SW. 850 mb temps will increase towards
18 to 21 degrees C Friday and Saturday along with 500 mb heights
increasing to 588 to 594 dm. The warmest days in the near term are
forecast to occur on Sunday and Monday: coastal and bay shore
highs will be in the upper 60s to low 80s while inland areas range
mid 80s to mid 90s...a few upper 90s in the far interior.

What should be noted with this warming trend is that we`re not
expecting afternoon highs to be WELL above normal. In fact, 5-8
degrees above normal is probably the most we`ll see which is not
as significant as the 15 to 20 degrees above normal we saw in the
June heat events. Heat Risk continues to be at Low Risk for much
of our CWA with some Moderate Risk mixed in for Sunday and Monday
across the interior. Even the ECMWF EFI (extreme forecast index)
is only showing about 50 to 60 percent for max temp on Monday
indicating it`s not an extreme event.

For the extended, it looks as though our region will be in between
the center of the high pressure over the desert SW and the
lingering trough over Canada & the PacNW. The trough seems to dig
a little southward on Tuesday which would bring slight cooling,
but then the high pressure begins to dominate again. Looking
ahead at the ECMWF and GFS ensembles...they both show the peak
warm up for Sunday and Monday followed by that slight cooling on
Tuesday with warming again for the rest of next week. However,
once again, we`re not yet seeing a strong heat signal as peak
temps will likely stay in the 90s across the interior and not
reach triple digits.

&& of 4:44 AM PDT Wednesday...For the 12Z TAFs.
Expect varying cloud heights to continue with mostly under the
MVFR and IFR criteria lasting into the mid to late morning with
light to moderate winds. Widespread VFR returns with mid clouds in
the late morning and early afternoon with winds becoming moderate
to breezy. Low clouds will be slower to fill the bays and move
inland tonight, offering another batch of MVFR CIGs and patchy

Vicinity of KSFO...MVFR with light winds through the late morning
with some intermittent times of IFR. Expect VFR for the afternoon
with moderate to breezy westerly winds peaking around 15 kts with 22
kt gusts. These winds will ease into the night. Lower clouds look to
begin fill around the SF Bay in the late evening, leading to another
night of MVFR.

KSFO Bridge Approach...Similar to SFO.

Monterey Bay...MVFR with moments of IFR and mist through the late
morning. Winds will be light but become more moderate and breezy for
the afternoon. MVFR CIGs are expected to return for Wednesday
evening as winds begin to reduce and stratus moves inland.

&& of 04:07 AM PDT Wednesday...Generally light winds
will prevail over the coastal waters tonight and Wednesday, aside
from increases off the Santa Cruz County and Big Sur coasts during
the afternoon. Somewhat breezier conditions will then develop
generally, while winds increase more substantially in jets off the
aforementioned coastal stretches, and subsequently off the coast
of Sonoma County as well. These will be accompanied by
increasingly steep, short period wind-waves with seas becoming
hazardous for smaller craft.


     .Tday...SCA...Mry Bay from 3 PM



MARINE: Murdock

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NWS MTR Office Area Forecast Discussion