Rain, Wind Arrive on Christmas, Opening Storm Door.

Share with Friends

California has been waiting for sizable storms that will spread rain across large areas of the state, and now it appears those storms are on the horizon. For the North Bay it also means beneficial rains that will help close the rainfall deficit for the fall and early winter.

The latest model trends show a significant storm arriving mid to late on Christmas Day and continuing into the 26th. That will be followed by another on Sunday the 27th, and perhaps another a few days later. Now the details.

The latest satellite picture shows a train of storms lined up in the Northern Pacific. The first one, arriving Tuesday, will be mostly dry. But that will set the stage for bigger, stronger storms in the following days. (Image 1)

Helping to drive the storms will be a strong jet stream currently setting up and forecast to aim straight at Northern California.
By late on Christmas Day, a strong 150mph plus jet in the upper atmosphere will be helping to push storms into California. (Image 2)

As for storms, a weak one will pass to our north on Tuesday. We may see a few clouds and perhaps a shower in the northernmost areas of the region. (Image 3) But this mostly dry trough will help to usher in storms that will dig further south.

The real action will begin on Thursday, Christmas Eve, as the first clouds arrive. The initial moisture will likely be aimed south of us, but that will change. Rain and gusty winds will follow on Christmas Day as a branch of the jet stream aims at our area, pulling moisture and in and the possibility of at least a weak atmospheric river somewhere along the central California coast. (Images 4 and 5)

As for rainfall, the models vary widely, from well over an inch to somewhat less. The GFS model shows Santa Rosa getting about an inch and a quarter, with more in the hills. (Images 6 and 7)

On Sunday, another storm is likely, and this may also bring significant rain. (Image 8) And yet another storm may move in around the 30th. A few models are hinting at a weak AR aimed toward California. We’ll see.

Of course, that’s in the long range, and those forecasts tend to be unreliable. But what’s certain is that the models agree on a good dose of rain beginning Christmas Day, and continuing off and on through the middle of next week. Here is the ensemble forecast (average of many runs) for rain. It shows possibly 2-3 plus inches piling up in places across the North Bay. (Image 9) The GFS and other models tend to agree. (Image 10) Stay tuned!