920
FXUS66 KMTR 140718
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1218 AM PDT Tue May 14 2024

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

.SYNOPSIS...
Issued at 1217 PM PDT Mon May 13 2024

Relatively quiet pattern persists through the forecast period with
morning marine stratus and clear skies elsewhere. Inland
temperatures warm into the 70s and 80s each afternoon with a
persistent marine layer keeping coastal highs in the 60s.

&&

.SHORT TERM...
(Today and tonight)
Issued at 1217 AM PDT Tue May 14 2024

Low pressure aloft will migrate from SoCal into the Desert Southwest
as an expansive high pressure ridge encompasses much of the
northeast Pacific. Our area will remain on the eastern periphery of
the upper ridge with minimal changes to our sensible weather. A
relatively deep marine layer around 1.5-2 kft was evident via area
profilers early this morning, with low stratus clouds spilling
inland across most of the area. Expect the top of the marine layer
inversion to remain relatively steady this morning before
compressing slightly as high pressure gains a bit more influence.
However despite these modulations it`s mostly a rinse and repeat
forecast. Cloudy skies for the coast and marine influenced valleys
overnight with a gradual clearing towards the beaches during the
late morning to early afternoon hours. High temperatures will range
from the 60s along the coast and bays to the upper 70s and 80s for
the warmest inland locations. As mentioned in the previous
discussion some of the model temperature guidance seems a touch too
warm when compared to observations over the past few days, so
followed the previous forecast philosophy of trending slightly
cooler for readings in areas which are likely to see a stronger
marine influence. Otherwise not much else to add with overnight lows
remaining seasonal in the upper 40s and 50s.

&&

.LONG TERM...
(Wednesday through Monday)
Issued at 1217 AM PDT Tue May 14 2024

The upper level ridge will gain slight prominence through midweek,
however we will remain along its periphery with a minimal increase
in temperatures inland. Readings will range from the 60s along the
coast to the upper 80s for the warmest inland valleys. A few hot
spots may crack the 90 degree mark. Lows will be mostly in the 50s.
The daily ebb and flow of coastal clouds will continue, with
coverage spreading inland each night with a gradual retreat towards
the coast by afternoon. The upper level pattern may transition more
towards troughing by early next week but dry weather still looks to
be the most probable forecast outcome.

&&

.AVIATION...
(06Z TAFS)
Issued at 1038 PM PDT Mon May 13 2024

Currently seeing a mix of VFR-LIFR at the terminals. The marine
layer continues to be allowed to deepen thanks to a weak upper-
level low with the depth somewhere in the 1,500-1,800 foot range.
This deeper marine layer will allow for stratus to penetrate
further inland and impact all terminals within the TAF period.
Highest confidence is in IFR-low-end MVFR at LVK, MRY, SFO, SJC,
and SNS and LIFR at APC and STS. OAK has the greatest uncertainty
as to whether or not the ceiling will be IFR or LIFR; while not
high, highest confidence is in IFR based on persistence and a
deepening marine layer, but the terminal`s proximity to APC could
allow for the terminal to go LIFR. Widespread VFR and breezy
onshore flow will prevail by tomorrow afternoon.

Vicinity of SFO...Currently VFR with breezy westerly flow. An IFR-
low-end MVFR ceiling will impact the terminal again overnight with
conditions improving to VFR by late-morning. Winds will remain
onshore and breezy through the TAF period with gusts up to 25
knots to be expected tomorrow afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently IFR with westerly flow at MRY and
MVFR with northwesterly flow at SNS. Confidence is highest in
ceilings remaining IFR-low-end MVFR overnight. VFR to prevail by the
afternoon. Winds will remain onshore through the TAF period. MRY
quickly deteriorates again tomorrow evening with SNS looking to
deteriorate into the next TAF cycle.

&&

.MARINE...
(Tonight through next Sunday)
Issued at 1038 PM PDT Mon May 13 2024

  Moderate to fresh northwesterly winds continue through the
middle of  the work week before diminishing to gentle to moderate
beginning  Wednesday. Occasional near gale force to gale force
gusts are  possible across portions of the northern outer waters
overnight  Monday into Tuesday morning. Winds will become more
west to  southwesterly and gusts are expected to strengthen across
the  northern outer waters heading into the late week and weekend.
Overcast conditions and widespread stratus continue across the
coastal waters as surface high pressure builds. Significant wave
heights across the central and northern outer waters will build to
10-14 feet by mid- week before seas diminish by late week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PDT this evening for Pt Arena to
     Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...SPM
LONG TERM....SPM
AVIATION...Sarment
MARINE...Kennedy

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