Marine Weather and Tide Forecast for Norris Canyon, CA

SHORT TERM
(This evening through Monday)
Issued at 331 PM PDT Sun May 11 2025

A relatively slow moving and positively tilted upper low will begin to move onshore tonight. Best chances for rainfall will be late tonight through early Monday afternoon across the North Bay and Bay Area. Little to no impacts are expected from the light rain, with lesser chances extending south into the Central Coast through Monday afternoon as well. The clouds and return of a more robust marine layer will end a stretch of great weather across our coastal communities the past week and bring some relief to the interior with more seasonal daytime highs. There is a slight chance of an isolated thunderstorm Monday morning as the upper trough axis approaches the shoreline, but confidence is too low for mention in the forecast attm. Morning stratus will return with the increased onshore flow, with some clearing expected by midday along the coast. Inland temperatures will see a noticeable change in daytime highs tomorrow from today's values, generally around 10 degree difference.

LONG TERM
(Monday night through next Saturday)
Issued at 331 PM PDT Sun May 11 2025

As the upper low slowly treks toward the interior Monday into Tuesday, we'll see rain chances come to an end with drier air in the midlevels advecting south across our area. Weak ridging will briefly peak on Thursday as strong shortwave energy well to our north flattens the ridging. High temperatures through the extended will peak on Thursday, with temperatures hovering near normal for much of the extended forecast. While the longwave pattern remains progressive through the extended forecast, impacts are limited.

AVIATION
(00Z TAFS)
Issued at 535 PM PDT Sun May 11 2025

Surface to lower level cool air advection, plenty of mixing and areas of breezy to gusty southwest to west surface winds are resulting in VFR this afternoon. Lower level cool air advection continues to weaken and lift the lower level temperature inversion per recent Fort Ord and Point Sur profilers. To the north over Marin and Sonoma counties diurnal surface warming and modest surface based instability is resulting in few-scattered strato-cu clouds. The current pattern supports VFR continuing across much of the Bay Area and north Central Coast into the evening.

Low clouds along a cold front arrive tonight and Monday morning along with showers, perhaps steady rain at times especially e.g.
at Santa Rosa Airport with a combination of upsloping southerly wind and weak pre-frontal warm sector arriving before the cold front producing IFR-MVFR in rain. Showers extend to the south to the north Central Coast Monday. Improving conditions to VFR return during the afternoon and evening. Gusty west to northwest winds redeveloping Monday afternoon and evening.

Vicinity of SFO...Near high confidence VFR continues through the evening, thereafter a lower cloud ceiling and visibility /MVFR/ develops with showers mainly Monday morning, a few lingering showers are possible in the afternoon. West wind gusts to near 25 knots this evening, decreasing after 04z to around 10 knots, west wind increasing Monday afternoon with gusts to 25 knots.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Near high confidence VFR continues through early to mid evening, thereafter patchy low clouds /VFR-MVFR/ may form nearby the terminals due to ongoing onshore winds, upsloping and lower level cool air advection. By early Monday morning low clouds will have a better chance of forming and there may be a few showers Monday. Generally VFR-MVFR during the 00z TAF cycle.

MARINE
(Tonight through next Friday)
Issued at 453 PM PDT Sun May 11 2025

Breezy and gusty winds continue with near gale force gusts through the evening for the southern most waters. Moderate to fresh west to northwest winds linger into Monday morning. Light rain will enter from the northwest late tonight and exit the region by mid to late Monday morning. Winds will be diminishing in the wake of the frontal passage. Winds increase once again toward the middle of the upcoming week. Moderate seas continue through the end of the forecast period.

MTR WATCHES/WARNINGS/ADVISORIES
CA...None.
PZ...Small Craft Advisory until 9 PM PDT this evening for Mry Bay-Pt Reyes to Pigeon Pt 0-10 nm-SF Bay N of Bay Bridge.

Small Craft Advisory until 3 AM PDT Monday for Pt Pinos to Pt Piedras Blancas 0-10 nm.