Rain through Christmas morning

That should transition into another evening of bad weather and heavy rainfall all the way into the early hours of Christmas morning on Thursday, with three-quarters of an inch to an inch of rain, Behringer said. Thursday afternoon will be gentler, with the possibility for sun breaks, and Friday will also be mostly dry. 

The storm is actually the same weather event that has been causing drizzles and gray skies across the Bay Area for the past week, Behringer said, and should be departing the Bay Area by the end of the week. 

It’s not extraordinarily unusual to see a storm of this magnitude in December, he said, however, it’s more typical for the January and February months. 

“We have seen this a few times this year before,” Behringer said. “It is on the stronger side.” 

Rainfall totals for the water year are at 86% of average levels at San Francisco International Airport and follow similar trends across the county, he said, meaning that the storm is likely to cause less damage than if water levels were above average. 

“The good thing thus far is we are pretty much at or below normal rain [levels],” Behringer said. “That’s kind of the saving grace.” 

The Bay Area isn’t at risk for any major river flooding, he said, however, urban roads may be at risk for ponding and downed trees due to the high winds are another concern. 

There aren’t any planned Pacific Gas and Electric power shut-offs planned for the area, a representative for the company said, although the rainy and windy weather may cause a potential for unplanned outages. 

In the coastal and mountainous areas of San Mateo County, the storm will likely cause more severe rain and wind, Behringer said, with gusts of up to 60 to 80 mph along the ridgeline and rainfall of 3 to 3.5 inches along the coast. 

It’s advised that residents take caution while the storm is in force, particularly while driving or walking in the early Christmas morning hours, when winds may be severe, as well as in tree-heavy areas. 

“People out on a walk or driving out and about, really use caution during that time,” he said. “As usual we always recommend — don’t drive over flooded roadway. If a roadway is closed, you might not know what’s underneath.”