A potent midweek storm is expected to bring widespread rain, colder temperatures and gusty winds across the Bay Area and portions of the Central Coast beginning Wednesday, forecasters said Tuesday.

The proverbial calm before the storm was evident as the National Weather Service said in its daily forecast discussion that Tuesday will be warm and dry, with some inland areas reaching the 70s and lower 80s. However, conditions will shift sharply by Wednesday as a strong Pacific system moves toward the coast.

Ahead of the storm, the Weather Service issued a small craft advisory for the Northern California coast, as well as San Pablo Bay, Suisun Bay, the West Delta and the San Francisco Bay north of the Bay Bridge, for Wednesday, 9 a.m. to 3 p.m., followed by a gale warning in effect from 3 p.m. Wednesday until 3 a.m. Thursday. Meanwhile, a wind advisory was also issued for the Bay Area and Central Coast beginning at 10 p.m. Wednesday until 10 a.m. Thursday.

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The first rain was forecast to spread into the region late Wednesday and continue through Thursday, with the heaviest totals, some 2 to 3 inches, expected in the coastal ranges. Elsewhere in higher terrains, at least 1 to 2 inches of rain is expected in the North Bay, with the city of San Francisco seeing up to 1.25 inches, the Weather Service said. Interior valleys and the Monterey Bay region are likely to see less than an inch, with some typically rain-shadowed valleys receiving significantly less, the Weather Service said.

Strong southerly winds will accompany the rain, with gusts of 35 to 45 mph in interior valleys and 45 to 55 mph along the coast and higher elevations. Some favored gaps and passes could see gusts exceeding 60 mph. The system may also produce isolated thunderstorms, though the Weather Service said the chances remain low and any storms are not expected to be severe.  

Temperatures across the region will cool notably as clouds and precipitation move in, ending the recent string of unseasonably warm days. Wednesday highs in the San Francisco Bay Area will be in the 60s and lows in the mid-50s, while the Monterey Bay Area will reach highs into the upper 60s and lows in the mid-50s. 

Showers are likely to linger into Friday before a brief drying trend begins on Saturday.