'The storm door is cracked open': Rain enters forecast for Bay Area

A woman walks along the seawall at Fort Point near the Golden Gate Bridge December 28, 2005 in San Francisco. A woman walks along the seawall at Fort Point near the Golden Gate Bridge December 28, 2005 in San Francisco. Photo: Justin Sullivan/Getty Images Photo: Justin Sullivan/Getty Images Image 1 of / 24 Caption Close 'The storm door is cracked open': Rain enters forecast for Bay Area 1 / 24 Back to Gallery

After a prolonged period of dry weather, the chance of rain has finally entered the San Francisco Bay Area forecast, meteorologists say.

The storm systems expected to sweep the region next week don't look to be rain-soaking atmospheric rivers, but they will likely deliver more than drizzle.

"I would say the storm door is cracked open," said Roger Gass, a meteorologist with the National Weather Service. "Normally when we use the reference 'the storm door is open' we see back-to-back systems or several systems basically in queue across the Pacific headed our way. We’re not seeing quite that, but it is trending into an active pattern with some potential for rainfall."

Projected rainfall amounts and specific timing are unclear, but the chance of rain generally runs from Tuesday to Friday next week.

"We're expecting scattered showers across those days," said Gass.

The region has seen exceptionally low rainfall totals since the start of the rainy season on Oct. 1 with weather systems known as high-pressure ridges hunkered down along the West Coast and blocking storm systems.

Downtown San Francisco has measured .03 inch since Oct. 1. Normally through Nov. 21, the city would expect to see 3.06 inches. The Santa Rosa Airport has measured .05. The average value for this time of year is 4.98. San Jose has recorded .06 compared to the seasonal average of 1.79 inches.

Leading up to Tuesday, the area is forecast to see mostly sunny skies and average temperatures with widespread 60s in the afternoon and overnight lows in the 40s along the coast and in the mid-30s to low-40s in inland areas.

"We may see a slight warming in the weekend, but still in the 60s and some interior valleys may reach 70s," said Gass.

On Sunday going into Monday morning, blustery weather is in the forecast with northerly winds developing. Offshore wind events can increase wildfire risk and have led Pacific Gas and Electric to deliberately shutoff power to prevent wind-damaged equipment from throwing sparks.

"Right now those details are hard to nail down," said Gass. "There’s not a lot of confidence with respect to wind. Right now it’s in the monitor stage and not one of great concern at the moment."

Pacific Gas and Electric said in a statement the situation is being "actively monitored."

"At this time, no determination has been made on a potential PSPS," PG&E spokesperson Mayra Tostado said.

Amy Graff is a digital editor with SFGATE. Email her at agraff@sfgate.com.