Marine Weather and Tide Forecast for Concord, CA

DISCUSSION

...Today - Tuesday...

Lingering mountain shower and isolated thunderstorm chances continue through this evening as the system that brought widespread precipitation impacts to the region through the weekend departs. While additional precipitation totals will remain light, thunderstorm chances sit around 5-15% through tonight, with highest potential across the mountains/foothills south of Highway 50. Dry weather is expected to prevail elsewhere today, with Tuesday remaining dry area wide as well. With weakening winds and clearing skies overnight some 30-50% probabilities exist for patchy Valley fog development on Tuesday morning.

Midweek

Moving into Wednesday, a quick moving system looks to introduce light mountain rain and snow shower chances by Wednesday morning.
Current NBM probabilities of rainfall greater than 0.25" sit around 30-50%, with highest chances across the Sierra/southern Cascades and the Shasta County terrain. Snow levels are expected to remain around 6000 feet through Wednesday evening when the bulk of the precipitation is anticipated. As dry weather continues at lower elevations through this event, increasing north to east winds are looking likely as the system departs on Thursday. Wind gusts 25 to 35 mph are generally expected throughout the Valley, although NBM probabilities of gusts up to 40 mph around 20-40% do exist for the northern and central Sacramento Valley on Thursday.

Late Week into the Weekend

As the midweek system continues to eject eastward through the end of the week, breezy north winds are likely to persist on Friday before trending lighter by the weekend. Dry weather is expected to persist on Friday and Saturday as a brief period of ridging aloft builds in over the weekend. This will allow temperatures to return to near to above normal through the first half of the weekend. Ensemble guidance does indicate additional periods of active weather as another deepening trough arrives Sunday into early next week. While exact details remain variable at this time, rain/mountain snow, isolated thunderstorm chances, and breezy to gusty onshore winds will all be possible given the current forecast trajectory of the system. At the moment, the trough does look more progressive and quick moving relative to the system that brought widespread, prolonged impacts last week and through the weekend.



AVIATION

General VFR conditions are expected over the next 24 hours. Areas of MVFR/IFR/LIFR conditions are possible in the Valley tomorrow between 10-18Z Tuesday morning due to low clouds and patchy FG/BR.
Currently there is a 30 to 50% chance of visibilities less than 1/2 mile in the Central Sacramento Valley tomorrow morning.

Chances for isolated showers and thunderstorms continue today over the mountains which may result in areas of MVFR/IFR conditions between 21Z and 06Z. Winds may be erratic with direction and speed in and around thunderstorm activity.

Surface winds will be generally 12kts or less, with periodic northwest gusts 15 to 20 kts in the northern San Joaquin Valley and Delta between 22Z and 04Z today.

STO WATCHES/WARNINGS/ADVISORIES
None.