Altadena, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

627
FXUS66 KMTR 031811
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1011 AM PST Tue Dec 3 2024

...New UPDATE...

.SYNOPSIS...
Issued at 157 AM PST Tue Dec 3 2024

Above normal temperatures and dry conditions will continue to
prevail through the week.

&&

.UPDATE...
Issued at 956 AM PST Tue Dec 3 2024

Mostly clear skies to kick off the day across the Bay Area and
Central Coast. However, there are two exceptions: fog over the
coastal waters/Big Sur coast and mid-high level alto-cu over the
Central Coast. First the fog, satellite imagery and coastal cams
shows fog hugging the Big Sur coast and lurking over the coastal
waters south of Monterey Bay. Impacts will be mainly to mariners
and motorists traveling along Hwy 1 south of Carmel by the Sea. As
for the alto-cu, these clouds are associated with a weak upper
level disturbance barely discernible on water vapor imagery.
Model guidance has it picked as a weak shortwave or weak upper
low. Not expecting much in the way of impacts.

No updated needed this morning. It will be a pleasant winter day
around the region with mainly sunny skies and above normal
temperatures.

MM

&&

.SHORT TERM...
(Today and tonight)
Issued at 157 AM PST Tue Dec 3 2024

GOES-West Nighttime Microphysics tells us all we need to know, let`s
take a look from north to south. A weak low pressure system situated
over the North Bay is bringing mid-level clouds to Northern
California, stratus can be seen developing along the Big Sur Coast
and spreading northward, and a mid-level cloud shield associated
with a weak low pressure system off the California/Mexico border is
extending into the Desert Southwest. Aside from that, generally
clear skies and calm conditions are being observed across the
region. Because of this, patchy dense fog will likely develop in
favorable coastal and valley locations with some already being
observed on the ALERTCalifornia cameras in the Russian River Valley.
While Watsonville Airport is not yet a climate site due to it being
too young (less than 30 years old), it did break a record for daily
maximum temperature on December 2nd by reaching 72 degrees, breaking
the previous record of 70 degrees set in 2006. The warming trend
continues with Oakland Museum forecast to reach 68 degrees today
which would break the previous daily maximum temperature record of
67 degrees set in 2014.

&&

.LONG TERM...
(Wednesday through Monday)
Issued at 157 AM PST Tue Dec 3 2024

A Rex Block pattern will develop as a ridge of high pressure
continues to build across the West Coast and low pressure develops
over the Desert Southwest allowing for above normal temperatures and
dry conditions to prevail. The first of a pair of shortwaves set to
skirt the region will bring increasing cloud cover and a slight
chance of precipitation to the northern outer waters on Thursday.
The second shortwave on Saturday is expected to be stronger,
bringing the warming trend to a halt with slight chances of
precipitation extending across the outer waters and moderate
northerly breezes developing. To no avail, it is likely that a
ridge of high pressure will develop again in the wake.

&&

.AVIATION...
(18Z TAFS)
Issued at 947 AM PST Tue Dec 3 2024

VFR through the TAF period for all but STS which will see pockets
of fog in the late night. Winds will be limited to local effects
for several sites, meaning light and mostly variable winds for
much of the area aside from moderate north and northwest winds in
the afternoons. Some southeast drainage winds look to affect SNS
early Wednesday, but don`t look impactful.

Vicinity of SFO...VFR through the TAF period. Light and variable
winds linger into the afternoon before turning morn west-
northwest. Expect winds to become light again in the late night.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR through the TAF period. Expect light
winds through the TAF period at MRy, while SNS stays mostly light
with moderate Southeasterly drainage winds affecting the site
early Wednesday morning.

&&

.MARINE...
(Today through Sunday)
Issued at 947 AM PST Tue Dec 3 2024

The longer period northwest swell continues through the week with
light to moderate north winds resulting in a light to moderate
sea state. No other major hazards expected.

&&

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

$$

SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...Murdock
MARINE...Murdock

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