San Geronimo, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

228
FXUS66 KMTR 272209
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
209 PM PST Fri Dec 27 2024

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

.SYNOPSIS...
Issued at 206 PM PST Fri Dec 27 2024

Unsettled weather continues through Sunday, with conditions drying
out late Sunday afternoon or evening. Then dry weather looks to
persist through much of the week, with some chilly mornings on tap.


&&

.SHORT TERM...
(This evening through Saturday)
Issued at 206 PM PST Fri Dec 27 2024

The main story for the rest of today and into tomorrow is the rain
chance for our service area. Model guidance from this morning shows
much of the region should remain dry over through much of the
afternoon and into the early evening hours. Current thinking is that
the North Bay counties could see rain arrive somewhere between 4pm-
10pm, with chances substantially increasing after midnight. The
question then becomes, how far south will this disturbance get?
Opted to trim PoP northward, keeping precip chances highest
surrounding the North Bay, San Francisco Peninsula, and clipping the
western side of the East Bay. Showers could skirt south into Santa
Cruz and the South Bay by tomorrow, but confidence is low in that
occuring. The rest of the Central Coast should remain fairly dry.
Rain chances lift back to the north, with light rain or showers
potentially lingering for North Bay counties on Saturday.

&&

.LONG TERM...
(Saturday night through next Thursday)
Issued at 206 PM PST Fri Dec 27 2024

Little has changed in the extended with zonal flow holding through
the early portion of the week. An upper level disturbance will
barrel through the PacNW Sunday into early Monday, which should be
the last hurrah for rain for us as ridging builds behind it. Another
disturbance tracks just to our north Monday into Tuesday, but that
looks to stay to our north and keep us dry. Cooler air will be
associated with these troughs leading to some chilly mornings for
the start of the work week. Will need to keep an eye out for any
sort of frost advisories for the North Bay Valleys and interior
Monterey and San Benito counties as temperatures look to fall into
the 30s. Ridging looks to build for midweek, with chilly mornings
continuing for Wednesday. Beyond that, ensemble and model guidance
start to differ around the New Year / beginning of January. New
Year`s Eve and Day have trended drier with the latest NBM
guidance. Wet weather chances have been pushed back towards the
weekend.

&&

.AVIATION...
(18Z TAFS)
Issued at 1052 AM PST Fri Dec 27 2024

Spotty lower CIGs and prevailing mid-level clouds continue to affect
the area. Winds stay light to moderate through the TAF period. The
next set of showers arrives into the night, bringing reduced
visibilities as they spread across the region. Shower chances reduce
in the mid to late morning before exiting into Saturday afternoon.
However, lower cloud cover looks linger beyond the forecast period.

Vicinity of SFO...MVFR CIGs scatter this afternoon with light to
moderate west winds affecting the SF Bay. IFR CIGs build overnight
as showers arrive and visibilities reduce. Shower activity reduces in
the late morning on Saturday as CIGs rise to MVFR levels and
visibilities improve.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...IFR/MVFR CIGs lift and scatter this
afternoon as moderate west winds build. These winds reduce and
become light into the late evening. IFR/MVFR CIGs return in the late
night as light showers arrive. Showers will also cause reductions in
visibilities. Shower activity reduces in the mid morning with rising
CIGs.

&&

.MARINE...
(Today through Wednesday)
Issued at 1052 AM PST Fri Dec 27 2024

Winds will temporarily shift to the west across the coastal waters
and bays this morning. On Sunday a cold front will arrive from the
northwest bringing additional wet weather and gusty winds, winds
shifting to northwest Sunday afternoon. A high pressure system
will move across the coastal waters and bays bringing dry weather
early next week.

&&

.BEACHES...
Issued at 1054 AM PST Thu Dec 26 2024

A High Surf Advisory is in effect through 4 AM Sunday. Large NW
swell will persist through late Saturday night to early Sunday
morning. This will be roughly 15 feet with a 15 second period,
translating to 20-30 foot breaking waves, depending on the beach
orientation and bathymetry (beach slope). The waves will peak
Friday and begin to abate through the day Saturday. Inexperienced
swimmers should stay out of the water, wave watchers should
maintain a safe distance, and no one should ever turn their back
on the ocean. Let`s get through this weekend without another ocean
fatality.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory until 4 AM PST Sunday for CAZ006-505-509-529-
     530.

PZ...Small Craft Advisory until 9 AM PST Saturday for Mry Bay.

     Small Craft Advisory until 9 PM PST Saturday for 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 Arena to Pt Reyes 10-60 NM-Pt Pinos to Pt
     Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

&&

$$

SHORT TERM...KR
LONG TERM....KR
AVIATION...Murdock
MARINE...KR

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