Campbell, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

183
FXUS66 KMTR 111058
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
358 AM PDT Tue Mar 11 2025

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

.SYNOPSIS...
Issued at 357 AM PDT Tue Mar 11 2025

An active period of weather sets in later tonight and persists
through the extended forecast. Periods of heavy rain Wednesday into
Thursday morning can be expected with gusty winds up to 50 MPH at
times along the coast, thunderstorms, potentially high surf and
accumulating snow across the highest elevations of the Santa Lucia
coastal range. Numerous rounds of light to moderate rain will move
across our Friday through the weekend and into the beginning of next
week.

&&

.SHORT TERM...
(Today and tonight)
Issued at 357 AM PDT Tue Mar 11 2025

After one more day of pleasant weather today, the forecast for the
first round of rainfall remains on track. Scattered light rain will
begin to move onshore over the North Bay as early as late this
afternoon and gradually increase in coverage and intensity through
the overnight into Wednesday. By sunrise tomorrow more intense
rainfall rates out ahead of the surface front will be ongoing over
portions of the North Bay. By mid-morning, the more intense rainfall
will begin to impact the Bay Area and East Bay, as the surface cold
front approaches the coast. Convergence along the cold front and
surging southerly winds just out ahead of the cold front will
produce wind gusts up to 50mph along the coast with periods of heavy
rain over the Bay Area likely from late morning through early
afternoon, eventually moving farther inland for the remainder of the
afternoon and early evening. Max wind gusts farther inland will be
in the 30-40mph range as the cold front pushes through with rainfall
rates up to 0.5"/hr. Urban flooding and small landslides in the
coastal ranges are possible where rainfall rates are highest.
Rainfall totals for the North Bay south into the coastal ranges of
Marin, Santa Cruz and Monterey County will approach 2" during the
day tomorrow, with lesser amounts inland, including some rain
shadowing into the South Bay.

&&

.LONG TERM...
(Wednesday through Monday)
Issued at 357 AM PDT Tue Mar 11 2025

Cooler air aloft associated with the center of the trough will
eventually lead to increased lapse rates and more unstable airmass
with a 10-15% chance for strong thunderstorms developing by
Wednesday evening in the post frontal airmass. However, the surface
trough loses some strength as it approaches land tomorrow evening
with weak short wave ridging aloft at the base of the trough. Strong
wind gusts up to 40mph and small hail are the primary concerns with
any updrafts able to remain organized enough to produce isolated
thunderstorms. Any thunderstorms that do develop should be
shortlived into the early hours of Thursday morning. Although rain
chances persist over much of the area through the day Thursday, it
will not be as widespread or intense as Wednesday. Expect mostly
light scattered rain chances gradually shifting south through the
day. The next round of rainfall begins to move onshore over the
North Bay late Thursday night into early Friday morning, a weak and
progressive trough axis embedded in a wide swath of northwest flow up
to 70kts at times shifts east across much of California during the
day Friday. Once again, scattered light rain chances linger into
Saturday, but most of the area will see little to no rain on
Saturday, with lingering cloud cover helping to keep temperatures 5-
10 degrees cooler than normal. Consensus for Sunday is lacking, with
the NBM possibly lagging behind most current NWP guidance, and may
trend drier over the next couple of updates, with potentially little
to no rain on Sunday. Furthermore, the upper level trough expected
for the beginning of next week has taken on a more positive tilt,
which would be drier and more progressive. Keep checking for updates
for the weekend and beyond as the forecast may change significantly
over the coming days.

&&

.AVIATION...
(06Z TAFS)
Issued at 945 PM PDT Mon Mar 10 2025

VFR continues area-wide per surface observations. The evening
Oakland upper air sounding showed 0.42" precipitable water which
was a little below early-mid March normal. The sounding showed the
air was saturated near the 500 mb level, however it was much
drier from 18 thousand feet to the ground level. 24 hour trends
show warmer air temps and lower dewpoint temps (less water vapor)
across a fair amount of the forecast area, this supports VFR
forecast tonight and Tuesday. Higher level cloudiness will slow
radiative cooling tonight and Tuesday morning.

Vicinity of SFO...It`s a near high confidence VFR forecast for
the 06z TAF. The winds around the terminal will likely become
light and variable tonight and Tuesday morning, with a westerly
wind near 10 knots resuming Tuesday afternoon and evening.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...It`s a near high confidence VFR forecast
for the 06z TAFs. Similar to the Bay Area, conditions aloft and
at the surface are mainly dry. High cloud cover will slow radiative
cooling tonight and Tuesday morning. Winds will become light
southeast tonight and Tuesday morning. Winds becoming west to
northwest near 10 knots Tuesday afternoon then light southeast by
mid Tuesday evening.

&&

.MARINE...
(Today through Sunday)
Issued at 357 AM PDT Tue Mar 11 2025

Moderate seas and winds will prevail today. Southerly winds will
increase Tuesday night into Wednesday as a strong cold front
approaches from the northwest with gale force gusts expected as
it passes. Scattered thunderstorms are possible Wednesday
afternoon into Thursday which would pose the risk for locally
heavy rainfall and gusty winds, lightning, and pea sized hail.
Seas will be rough to very rough Wednesday through the weekend.

&&

.BEACHES...
Issued at 429 PM PDT Mon Mar 10 2025

Moderate period westerly swell arrives along the coastline
Wednesday into Thursday. Expect westerly swell 7 to 9 feet
Wednesday increasing to 10 to 12 feet Wednesday night and
Thursday, with possibly higher breakers near 15 feet Thursday.
We`ll continue to monitor beach conditions through mid-week,
including potentially for increasing surf Sunday through Sunday
night.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 AM to 9 AM PDT Wednesday for Mry Bay-
     Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60
     NM-Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras
     Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm-SF Bay N of
     Bay Bridge.

     Gale Warning from 9 AM to 3 PM PDT Wednesday for Pigeon Pt to Pt
     Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Reyes to
     Pigeon Pt 0-10 nm-SF Bay N of Bay Bridge.

     Gale Warning from 9 AM to 9 PM PDT Wednesday for Mry Bay-Pigeon
     Pt to Pt Pinos 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10
     nm.

     Small Craft Advisory from 9 PM this evening to 3 AM PDT
     Wednesday for Pt Arena to Pt Reyes 10-60 NM.

     Gale Warning from 3 AM to 3 PM PDT Wednesday for Pt Arena to Pt
     Reyes 10-60 NM.

&&

$$

SHORT TERM...JM
LONG TERM....JM
AVIATION...Canepa
MARINE...Canepa

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