5 Killed By Falling Trees As 'Explosive' Storm Rattles The Bay

SAN FRANCISCO — The death toll continues to climb after a "bomb cyclone" detonated Tuesday across the Bay Area as one of the most powerful storms in recent memory claimed. Five people are now confirmed dead, many more are injured and nearly 200,000 customers were without power at the height of the storm.

The National Weather Service's Bay Area office reflected on the storm in a forecast discussion early Wednesday, noting the unique factors that lent to the system's overwhelming force.

"Wow. Even by the standards of what has turned out to be one of our most extraordinary winter seasons in a very long time, yesterday (Tuesday) stands out. Explosive cyclogenesis over the eastern Pacific resulted in a 984 mb low pressure center just west of the San Mateo County coast, and associated widespread strong and damaging winds and flooding rains. San Francisco Airport itself reported a minimum [sea level pressure] of 985 mb, which appears to set a new record for the month of March, and reported a peak wind gust of 64 mph (with an even more remarkable 74 mph peak wind at Oakland Airport."

AccuWeather meteorologist Brian Lada explains further:

"For a storm to be dubbed a bomb cyclone, the atmospheric pressure must drop at least 0.71 of an inch of mercury (24 millibars) in 24 hours. Tuesday’s storm blew this benchmark out of the water with a buoy in Monterey Bay, just south of Santa Cruz, recoding a pressure drop of 0.71 of an inch of mercury (24 millibars) in just 17 hours. The storm’s ferocity also generated a storm surge of two feet along the coast of central California. The storm was so intense that it appeared to develop an eye on satellite, similar to what is seen in tropical storms and hurricanes, although this week’s storm was much different than a tropical system."

The storm toppled trees and wires across the region, killing one man driving near Portola Valley and later killing the passenger in a car driving through a retirement community in Walnut Creek.

In San Francisco, officials on Wednesday confirmed two deaths from Tuesday's storm. Police said two people were hit by a tree in Lower Nob Hill, severely injuring both, and one victim later died at the hospital. In a separate incident, a person struck by branches in the city's Outer Sunset neighborhood was pronounced dead at the hospital. Later in the afternoon, police announced an on-duty sergeant was hit by a falling tree Tuesday and hospitalized with life-threatening injuries.

In Oakland, fire officials said one person died after a tree fell on their tent near Lake Merritt.

Windows fell from two San Francisco high-rises, rough waters disrupted ferry service, and several barges got loose, striking a nearby bridge. Winds toppled a big rig heading east on the Bay Bridge.

An Amtrak train traveling through Contra Costa County derailed Tuesday afternoon after hitting a downed tree. Fortunately, all cars remained upright and no injuries were reported.

A mudslide in Woodside left roughly 30 homes under evacuation recommendations Wednesday morning.

Power outages surged at a feverish pace through Tuesday afternoon, impacting nearly 200,000 customers across the Bay Area at 6 p.m. The impacts were felt strongest in the East Bay, where more than half the outages were reported. More than 78,000 remained without power by mid-morning Wednesday, primarily impacting East Bay and Peninsula customers.

Spring may have begun Monday, but there have been few signs of its arrival so far. The National Weather Service said Tuesday's storm helped push the rain total at Three Peaks into the triple digits.

A flood advisory in place for San Francisco, Alameda, San Mateo and Santa Clara counties was set to expire shortly before noon Wednesday. A coastal flood advisory will expire early Thursday.

Finally, the Bay Area is in for a well-deserved run of calmer, sunnier days. Afternoon highs around San Francisco should land in the mid-50s through the weekend amid mostly sunny skies. There is a hitch, though. Overnight lows are looking unusually cool late in the week.

"Friday night and then Saturday night especially, minimum temperatures are forecast to get unseasonably chilly," NWS forecasters wrote. "This is of particular concern in the Wine Country of the North Bay where 'bud break' has begun in the vineyards and lows look to then potentially reach down to freezing or below."

Beyond the weekend, more rain is looming. The National Weather Service said early models suggest another "unseasonably deep upper-level trough" developing off the California coast early next week. Better details on what to expect in terms of rain, wind and timing will be shared in the coming days.

The Associated Press contributed to this report.