Marine Weather and Tide Forecast for Martinez, CA

DISCUSSION

Today

As NorCal sits between the departing trough from the weekend and an approaching trough digging across the Pacific Northwest, a period of dry weather and breezy southerly winds remains on track for the remainder of today. Despite mostly sunny skies, high temperatures look to remain below normal, with upper 60s to low 70s across the Valley and 50s to low 60s at higher elevations. A slight chance for a light shower or two will be possible this evening across northern Shasta County with the approaching trough, but minimal impacts are expected.

Midweek

Moving into Wednesday, shower chances are expected to gradually increase across Shasta County and the surrounding terrain by mid morning, with rain and light mountain snow showers spreading toward mountain locations north of Highway 50 throughout the day.
Snow levels look to remain above 6000 feet through Wednesday, rapidly falling overnight into Thursday morning. Despite this, most precipitation is anticipated through Wednesday evening. Given the progressive nature of the system, NBM probabilities of rainfall greater than 0.25" remain around 30-50%, highest across the Shasta County terrain. Accumulating snowfall of a dusting to an inch will generally be confined to locations above 6000 feet.

As dry weather continues at lower elevations through this event, increasing north to east winds are looking likely as the system departs on Thursday. Current forecast trends indicate a slight southward shift in the expected midweek trough, which is expected to introduce a slight uptick in winds further southward to include the entire Sacramento Valley and the Delta. Wind gusts 25 to 35 mph are generally expected, although NBM probabilities of gusts up to 40 mph around 30-50% do exist for locations along and west of the Interstate 5 corridor and north of Highway 50.

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 with some Minor HeatRisk possible on Saturday from Sacramento southward. Ensemble guidance does indicate another deepening trough arriving Sunday into early next week. While ensemble guidance is in general agreement that this system will introduce additional periods of active weather, there remain some notable timing differences on when precipitation impacts are expected to begin a this time. Regardless, increasing chances for rain/mountain snow, isolated thunderstorms, and periods of breezy onshore winds are anticipated by at least early next week.

AVIATION

VFR conditions expected over the next 24 hours. Surface winds in the Valley will be breezy out of the west to southwest in the Sacramento Valley and north to northwest in the northern San Joaquin Valley until around 06Z Wednesday. Surface winds then expected below 12kts. There is a 10-20% chance of low clouds developing in the central/southern Sacramento Valley tomorrow morning between 14-18Z, however confidence is low.

A weak system will introduce isolated light precipitation over the northern Sacramento Valley and mountains/foothills after 18Z Wednesday with a 5-10% chance for isolated mountain thunderstorms which may lead to periods of MVFR/IFR conditions.

STO WATCHES/WARNINGS/ADVISORIES
None.