While most people woke up Wednesday morning expecting strong rain to come from the second atmospheric river storm in close succession, all they got was a light drizzle and moderate winds.

But as cities in the Tri-Valley warned their residents that the worst was yet to come, the significant rainfall and strong winds finally arrived on Wednesday evening and is set to continue into Thursday morning.

Fallen trees and limbs, as well as the threat of more flooding and power outages, were present throughout the region as the clock approached 10 p.m. and a forecast of even more rain and winds overnight.

"A powerful hurricane force low pressure system located over the eastern Pacific is set to surge a plume of moisture and damaging winds into the West Coast beginning tonight," according to the National Weather Service Bay Area website. "The greatest impacts, which include damaging winds, excessive rainfall, and extremely heavy snow, is forecast to occur over much of California and into southern Oregon through Thursday."

Tri-Valley residents didn't see steady rainfall until after 5 p.m. Wednesday.

In Pleasanton, city staff stated in a news release that they took advantage of the delay in wet weather by "continuing to clear storm drains, drainage pipes and trenches throughout the city."

"While continuing to prepare your residence or business is important, we want to make sure residents know how to stay informed and stay safe as we prepare for what the National Weather Services is calling an 'extreme' storm," according to the news release. "With large amounts of rain and wind gusts expected to reach up to 55 miles per hour, expect to see additional fallen trees and potential power outages that affect Pleasanton."

For those in Sunol who live on Kilkare Road, Palomares Road, and on Niles Canyon Road, the Alameda County Office of Emergency Services is recommending that they evacuate the area due to "the storms, saturated soils and current runoff."

The small town has already been dealing with severe flooding and damage at the Sunol Glen School, which houses just under 300 kindergarten to 8th grade students.

According to several update videos posted to the Sunol Glen Unified School District, Superintendent Molleen Barnes said that the school sustained substantial damage in the storms over the weekend with the most damage coming from Saturday's big storm.

Sinbad Creek, which is right next to the school, burst through the school's surrounding fence on Saturday night, damaging three classrooms and two offices, destroying the school's garden, athletic track and playground and leaving 8 inches of mud and downed trees in its wake.

The school's daycare classroom, tutoring center and art classroom had also been badly damaged.

Barnes said in the update videos that she and the rest of the community are working to clean up the mess in the next coming days so that the school could reopen by Jan. 9.

Apart from extra preparations local municipalities are taking to mitigate any serious damage to infrastructure, Gov. Gavin Newsom proclaimed a state of emergency throughout California to support the ongoing response to recent storms.

The proclamation supports emergency relief efforts including authorizing the mobilization of the California National Guard to support disaster response, directing Caltrans to request immediate assistance through the Federal Highway Administration's Emergency Relief Program to support highway repairs and other support for local response and recovery efforts.

Newsom also activated the State Operations Center to its highest level along with the Flood Operations Center, which covers forecasting, reservoir operations coordination and provides technical support as well as flood fighting materials, like sandbags, for local agencies.

"California is mobilizing to keep people safe from the impacts of the incoming storm," Newsom said in a news release. "This state of emergency will allow the state to respond quickly as the storm develops and support local officials in their ongoing response."

Other cities in the Tri-Valley spent most of Wednesday prepping for the rain and strong winds which are expected to hit the valley later on with sustained 30 miles per hour winds and wind gusts of up to 50 miles per hour.

Some of those early Wednesday winds already did some damage like in Livermore where the city's Public Works team and law enforcement responded to a large tree down near North P and Chestnut Streets.

"With saturated soils, we are expecting downed trees, downed lines and messy roads especially during the evening commute," according to a news release from Livermore. "Avoid travel if possible. It is never safe to drive through flooded intersections. Don't underestimate the depth of water."

The winds coupled with the saturated soil from the rain could lead to even more downed trees, which is why cities are urging residents to avoid driving Wednesday evening and night -- there's also the risk of getting your car stuck in flooded areas.

Residents are also being told to expect power outages as PG&E has indicated that they will occur.

In Dublin, all of the city facilities were closed to walk-in customers early in the day to also avoid having people travel. According to the city's Twitter page, these closures could extend to Thursday.

All of the trails in Dublin have also been closed.

Danville also saw significant amounts of flooding over the weekend as whole neighborhoods were filled with water as clean up crews worked to prevent mudslides on Diablo Road with sandbags.

"The vast majority of mud and debris has been removed from the Brookside area, more to be cleaned on side streets and drain inlets have been checked and cleared," according to a news release from the town. "Our contractors continue to work in the area and are on call if we need them."

The news release also stated that Danville responded to several calls in the past few days to address potential issues and will continue to do so with a crew staying after hours to respond to issues and a back up team to relieve them if issues persist later into the night.

According to the release, Danville staff participated in a California Governor's Office of Emergency Services briefing Wednesday at noon where they learned that this upcoming storm will not drop as much rain as the last one, and the duration will be shorter.

"This coincides with intel we received from the county (Office of Emergency Services) and the National Weather Service telling us that we could expect to see 2-3 inches," the Danville news release stated. "Two additional atmospheric rivers are expected to pass through later in the week."

Editor's note: Embarcadero Media East Bay Division editorial director Jeremy Walsh contributed to this report.