Canadian cold air mass sending North Bay temperatures plummeting

This week brought the North Bay the first below-freezing temperatures of the season.

In case the mall Santas hadn’t already tipped you off, it does appear that winter is coming.

In Healdsburg on Monday the overnight low dropped to 28 degrees, and at the Sonoma County airport the mercury plummeted to 30. Temperatures were expected to be similarly cold in the North Bay into this morning, with some areas even experiencing frost.

In Lake County, the news was chillier still, where a freeze warning was issued by the National Weather Service, noting that if pipes and plants were left uncovered they could incur damage.

The cold snap comes courtesy of Canada, and is part of a large cold air mass hovering over the northwestern United States, pushed south of its usual home by a low-pressure system.

But take heart, North Bay denizens, it could be worse. In northern Montana, also suffering under the swirling cloud of Canadian cold air, areas dipped into the negative single digits. On Thursday, lows in the North Bay will return to the mid-40s, but then it’s supposed to rain for three days.

By the time it tapers off Saturday, low-lying areas can expect 1 inch of rain, with up to 3 inches falling in the hills.

You can reach Staff Writer Christi Warren at 707-521-5205.