Marine Weather and Tide Forecast for Bay Point, CA

DISCUSSION

...Today - Monday...
Active weather continues across the area today as an upper low moves overhead, bringing showers, heavy mountain snow, breezy winds, and thunderstorms to the area (25-40% probability). Latest radar imagery shows scattered showers and isolated thunderstorm activity through the Valley and foothills, with scattered snow in the mountains above 4000-5000 feet. Instability and shear profiles suggest the potential for isolated strong to severe thunderstorms this afternoon and evening. Latest Hi-Res guidance shows a line of showers and thunderstorms moving across the area into early this afternoon, with the potential for additional thunderstorms the rest of the afternoon and evening hours. As the low pressure moves through, colder air shifts down, which could bring a slightly increased chance for cold air funnels to the area during the day on Sunday. Additional storm threats include 1+ inch hail, accumulating hail, strong winds, and localized flooding from heavy rain. Stay alert and stay prepared by having a way to receive watches, warnings, and statement this afternoon and evening.

Snow levels today will be around 4000-5000 feet, but could lower as low as 3500 feet in heavier convective showers. The heaviest snow is expected through this evening, with snowfall rates up to 1+ inch per hour. A Winter Storm Warning remains in effect for the northern Sierra and southern Cascades through 11 PM tonight.
Additional snow accumulations of 6 to 12 inches are expected above 4500 feet, with up to 18 inches at the highest peaks. Minor snowfall accumulations up to 1 to 3 inches down to 4000 feet.
Wind gusts as high as 40 mph. Mountain travel could be very difficult to impossible.

Breezy southerly winds are expected through this afternoon, with gusts up to 20-30 mph within portions of the Valley, northeast foothills, and mountains.

Lingering mountain showers are expected on Monday with minor impacts. In addition, the latest NBM suggests the potential for thunderstorm development over the Sierra south of Highway 88 (10-20% chance). Elsewhere, dry conditions are expected.

Early to Late Week

A return to drier and warmer conditions is expected early to mid next week with drier northwest flow. Signal is there for brief showers and mountain snow showers Wednesday and Thursday as the next trough drops down over the Great Basin area. NBM suggests a 20-50% probability of precipitation greater than 0.25 inches over the mountains; highest chances in Shasta County.

In addition, breezy northerly to easterly winds develop Thursday and Friday. The strongest winds are expected on Thursday, especially along and west of the I-5 corridor within the Sacramento Valley and mountains.

AVIATION

Areas of MVFR and IFR conditions in showers or thunderstorms through late tonight. Thunderstorm chances increase this afternoon and evening and continue into the overnight hours. Winds may be erratic with direction and speed in and around thunderstorm activity. Surface winds will be breezy out of the south, with gusts up to 20-25 kts at times in the Valley through this afternoon and up to 30-35 kts over the mountains through tonight. Otherwise, surface winds less than 12 kts are expected on Monday. Lingering mountain snow showers are expected through Monday, with the potential for isolated thunderstorms over the Sierra in Tuolumne County tomorrow afternoon.



STO WATCHES/WARNINGS/ADVISORIES
Winter Storm Warning until 11 PM PDT this evening for West Slope Northern Sierra Nevada-Western Plumas County/Lassen Park.