The majority of coastal California is at a significant risk of flooding today as a 'bomb cyclone' storm bears down, with some inland areas at risk as well, and officials in Watsonville are taking no chances and have issued mandatory evacuation orders.

Across the Bay Area there are sandbag shortages as residents prepare for the next bout of heavy rain — having seen a preview/reminder on New Year's Eve of what a whole ton of rain in a short period of time looks like in their neighborhoods.

But some cities are at much greater risk of widespread flooding than others, and they are preparing for the worst. On Tuesday evening, the City of Watsonville in Santa Cruz County issued a mandatory evacuation order for a large swath of the city. "If your residence is located within this map's blue-shaded area, you're asked to evacuate NOW or as soon as possible to safely get ahead of the storm's flooding," the city said in a tweet.

As KSBW reports, the city issued the order for "an area that is primarily made up of elderly and vulnerable members of the community and the city wanted to give them extra time to evacuate" given the probability of flooding.

An overnight shelter was established last night at Cesar Chavez Middle School.

A neighborhood has also been evacuated in the East Bay due to a mudslide threat. As KRON4 reports, the Seacliff neighborhood near Brickyard Cove in Point Richmond was evacuated Wednesday morning.

Elsewhere in the Bay Area, there were already some power outages as of 10:30 a.m. Wednesday — just over 5,000 PG&E customers were without power, as Bay Area News Group reports, with about half of those in the East Bay and 240 in San Francisco. PG&E said it was reserving almost 2,900 repair personnel today to respond to calls about power outages and downed power lines.

Up in Mendocino and Sonoma counties, towns near the Russian River are bracing potential flooding that may not arrive until Thursday. As the Press Democrat reports, the river is expected to rise to three times its current level as a result of the storm, and will likely top its banks.

Guerneville, which is particularly vulnerable to seasonal floods, is preparing for a major flood, though perhaps less severe than one it experienced in February 2019. The National Oceanic and Atmospheric Administration (NOAA) predicts that the river will crest at three feet above its 32-foot flood stage in the lower section where Guerneville lies, and that will likely impact some downtown businesses and homes. (The last major flood in 2019 crested at over 45 feet, for perspective.)

Free sandbags were being given out Wednesday morning for Sonoma County residents near the river at Monte Rio fire station, Forestville fire station, and Sonoma Landworks in Guerneville.

Guerneville could be in for a doozy of a winter, though, especially if more big storms line up like they have for the past week. Storm runoff reaching the river typically doesn't peak until late January, though the 2019 flood didn't occur until late February and didn't recede until early March.

As we get later into Wednesday and early Thursday, areas that may not typically be thought of as vulnerable to flooding could see water impacts start to emerge. The National Weather Service posted a map indicating elevated flood risk across most of California's western half, with the coastal section at the highest risk.

Top image: gwatsondesign/Twitter