000
FXUS66 KMTR 190915
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
215 AM PDT Fri Apr 19 2024

...New SYNOPSIS, SHORT TERM, LONG TERM...

.SYNOPSIS...
Issued at 215 AM PDT Fri Apr 19 2024

Cooler conditions are expected today and tomorrow with light drizzle
possible each morning. Temperatures rebound late weekend and early
next week. A return to unsettled conditions arrives Tuesday and
persist throughout late next week.

&&

.SHORT TERM...
(Today and tonight)
Issued at 215 AM PDT Fri Apr 19 2024

A well defined marine layer is in place this morning (around 1800-
2000 ft per Fort Ord Profiler) and will support patchy drizzle in
the upslope regions this morning. Otherwise, this afternoon sunny
conditions will return to inland areas with temperatures expected to
warm into the low to mid 70s. Meanwhile, the coast remains in the
upper 50s to mid 60s under mostly cloudy conditions.

Tonight, expecting clouds to make a return back inland and become
more widespread with low temperatures in the upper 40s to lower 50s.
Again, patchy drizzle will once again be possible. Saturday will
feature slightly warmer temperatures inland, but only by a few
degrees. Wind will also be on the increase with breezy northwest
winds near the coast, in the coastal hills, and into the region`s
valleys. Looking for gusts of 25-35 mph in these areas by Saturday
afternoon.

&&

.LONG TERM...
(Saturday through Thursday)
Issued at 215 AM PDT Fri Apr 19 2024

By Sunday and Monday, ridging dominates the pattern once again with
interior areas warming to near 80 degrees with 60s and 70s as one
gets closer to the coast. By Tuesday, a change to more unsettled
conditions return as an upper level low approaches the region. This
pattern will persist throughout late week and points to possible wet
weather during the latter half of the week. However, there is no
major concerns for flooding and may end up being widespread light
drizzle if not light rain. Temperatures also turn cooler with highs
in the upper 50s at the coast and mid-to-upper 60s inland from
Tuesday throughout late week. Stay tuned!

&&

.AVIATION...
(06Z TAFS)
Issued at 1114 PM PDT Thu Apr 18 2024

A mix of predominantly LIFR and IFR conditions through the night
tonight and the late morning of Friday. North Bay and Monterey Bay
terminals are likely to see LIFR conditions persisting through the
overnight hours and into the late morning as a result of fog and low
stratus CIGs. Sinking, drier air aloft is likely helping to lower
and squash CIGs down to around 1400 feet currently per the Bodega
Bay profiler, and 1800 feet per the Ft. Ord profiler. Expect these
CIGs to lower progressively through the night and into the morning
hours. Terminals in the SF Bay region are more likely to see MVFR
conditions per model suggestions, though confidence on this is only
moderate, given the low CIGs elsewhere. A drop into IFR CIGs for SF
Bay terminals overnight is not out of the question. Decent onshore
flow overnight will also be a factor in helping advect stratus
inland, leading to robust cloud coverage through at least the late
morning of Friday. In the early afternoon, as things heat up, clouds
should begin to mix out bringing a return of VFR conditions and
breezy to moderate onshore winds.


Vicinity of SFO...SFO in particular overnight appears to remain the
odd one out, as it is likely to remain in VFR territory, with good
agreement among numerous models. Despite good onshore flow overnight
around 6-7 knots, given the fact that the stratus deck currently
sits around 1400` and is expected to lower, stratus may not be able
to rise above and advect through the San Bruno gap, keeping
conditions clear and VFR locally at SFO terminal. Additionally, any
stratus that fills over the bay waters will be likely kept just on
the periphery of the SFO vicinity as good overnight flow out of
the west helps keep any stratus over the bay away and pushed more
towards the KOAK side. KOAK conversely will likely see IFR
conditions last through the nighttime as good overnight onshore
flow helps push stratus through the Golden Gate gap and into the
SF bay. Late clearing is expected at KOAK with VFR returning in
the late morning to early afternoon.

SFO Bridge Approach...IFR-LIFR conditions are likely as robust
stratus coverage develops overnight over the SF bay waters thanks to
good onshore flow. Clearing expected into the very late morning to
early afternoon of Friday to VFR.

Monterey Bay Terminals...IFR/LIFR through much of the night as a
result of very low CIGs. Stratus is expected to continue to lower
through the night. Some reductions in visibility are possible as
CIGs lower and the air reaches saturation near the ground, leading
to mist and fog development. However, confidence on mist and fog
development is not as strong as confidence in CIGs lowering. This
will be something to watch closely overnight. VFR returns in the
early afternoon though a FEW-SCT low clouds may linger, with winds
onshore and around 10 knots. Stratus makes an early return in the
evening of Friday.

&&

.MARINE...
(Tonight through next Wednesday)
Issued at 1114 PM PDT Thu Apr 18 2024

Expect light to moderate winds into the weekend before breezy to
gusty northerly winds arrive Saturday afternoon that will increase
hazardous conditions over the waters. Wave heights will start to
build heading into the late weekend before diminishing by mid-
week. Another moderate period northwest swell arrives over the
weekend as well as another light, longer period (18 seconds)
southerly swell.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...AC
MARINE...SO

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