NWS Forecast Area Discussion - San Francisco Area
000
FXUS66 KMTR 191146
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
446 AM PDT Tue Mar 19 2024
...New AVIATION...
.SYNOPSIS...
Issued at 301 AM PDT Tue Mar 19 2024
Despite the increase in coastal stratus, rain will stay out of the
forecast through Thursday. By Friday, a cold front will bring
periods of light to moderate rain and cooler temperatures through
the weekend.
&&
.SHORT TERM...
(Today and tonight)
Issued at 301 AM PDT Tue Mar 19 2024
The current low-cloud enhanced IR satellite image looks a lot like
early summer with a stratus-filled marine layer intruding into
coastal areas and neighboring valleys. The cloud base is a few
hundred feet lower than yesterday, and the Ft. Ord profiler is
measuring the marine layer depth at around 1,000 ft. This makes
patchy fog possible later this morning, and there is some
indication of mist beginning to form on regional traffic cameras.
The HRRR has a great handle on the current stratus coverage, and
suggests the low clouds will break by mid-day, allowing another
sunny and warm afternoon.
&&
.LONG TERM...
(Wednesday through Monday)
Issued at 301 AM PDT Tue Mar 19 2024
Wednesday and Thursday will be similar to Tuesday. Marine layer
stratus and patchy fog in the morning will give way to clear
afternoons and warmer than average temperatures. The pattern will
change on Friday as a cold front approaches from the Eastern
Pacific. Moderate southerly winds will shift to westerly in the
afternoon. Light to moderate rain is also expected on Friday,
although a few stronger showers are possible as the surface front
moves through. Unsettled weather will persist Saturday, although
precipitation will be more hit-or-miss showers compared to Friday.
Lingering light showers will likely persist into Sunday. In
addition to the rain and wind, the temperature will be noticeably
colder this weekend. Expect coastal areas to stay in the 50s,
while some inland valleys break into the low 60s. As an example of
this cool-down, Pinnacles National Park recorded a high
temperature of 79F Monday. The forecast high for Sunday is only
59F.
&&
.AVIATION...
(12Z TAFS)
Issued at 446 AM PDT Tue Mar 19 2024
IFR to LIFR conditions across the board. Primarily stratus
throughout the Bay Area and Central Coast with patches of fog mixed
in. Fog is starting to develop at STS with visibility rapidly
dropping over the last hour. Increased chances for temporary fog
development at SNS to continue through the early morning hours
with temporary dips in visibility and ceiling height possible.
Elsewhere, visibilities are expected to stay above 6SM but
temporary drops in visibility may be possible. VFR conditions will
return by mid to late morning between 17-19Z. Winds are light and
primarily out of the NW tonight with stronger W to SW winds
expected to return during the day. Guidance is hinting that
stratus is likely to return after 06Z tomorrow with some potential
for fog development in the North Bay.
Vicinity of SFO...IFR conditions. Conditions will start to improve
by 20Z with guidance suggesting conditions may start improving as
early as 18Z. Light SW winds overnight will strengthen to moderate W
to NW winds during the day and continue overnight. Moderate
confidence that stratus will return to SFO by 10Z tomorrow with
guidance hinting decreases in ceiling heights are likely.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...IFR to LIFR conditions to continue through
the remainder of the night. Patchy fog has been moving in and out of
SNS overnight. Some potential remains through 14-16Z for temporary
drops in visibility and ceiling heights at SNS as patchy fog moves
over the airport. At MRY, fog development is not expected but
temporary decreases in visibility may be possible between 13-16Z.
Light, variable winds overnight with winds strengthening and turning
westerly to northwesterly during the day. Tomorrow night, winds will
become light and variable again with stratus likely to return
between 04-06Z.
&&
.MARINE...
(Today through Sunday)
Issued at 301 AM PDT Tue Mar 19 2024
High pressure to continue through mid week with an incoming low
pressure system moving into the area on Thursday. Gentle NW winds
and dry conditions will linger through Wednesday before winds
strengthen and become more southerly late Wednesday into Thursday.
Rain chances will increase over the waters late Thursday with
elevated precipitation chances continuing into the weekend. A
moderate period northwesterly swell continues to diminish with a
new, longer period northwesterly swell train arriving Thursday.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 9 AM this morning to 9 AM PDT
Wednesday for Pt Pinos to Pt Piedras Blancas 0-10 nm.
&&
$$
SHORT TERM...Flynn
LONG TERM....Flynn
AVIATION...Kennedy
MARINE...Kennedy
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NWS MTR Office Area Forecast Discussion