The rain-weary Central Coast and Bay Area are being asked, again, to prepare for another round of soaking storms this week, as another atmospheric river system is expected to drench the region.
According to the National Weather Service, the atmospheric river is forecast to make landfall early Thursday, March 9. The entire Bay Area is already under a flood warning as of March 7, with a 40% chance of flash flooding forecast overnight Thursday into Friday.
“Initially, light rain will develop along the coast generally after sunrise as a warm front moves over the region ahead,” reads a March 7 post on the National Weather Service website. “By the afternoon and early (Thursday) evening, precipitation will increase in coverage and intensity as the (atmospheric river) takes aim at the central California coast. Instability will also increase during this time, resulting in a 15-30% probability of thunderstorms.
“Additionally, southerly winds will increase ahead of and along the main boundary with wind gusts of 40-50 mph across most lower elevations with 50-60 mph possible near the coast and in the coastal ranges, peaks and favored coastal gaps,” the NWS site continues. “Moderate to at times heavy rainfall will continue through Thursday night and into Friday morning as moist zonal flow advects moisture inland across the entire region.”
The rainfall will likely be heavily concentrated in the coastal ranges and North Bay mountains, which could see from 3 to 6 inches of rainfall during the atmospheric river, according to the NWS. Up to 8 inches of rain could fall in the Santa Cruz Mountains during the March 9-10 period.
Rainfall amounts could add up to between 2-4 inches in the inland hills, with valley floors and urban areas picking up between 1-3 inches of rain, according to the NWS.
The NWS cautions that wind gusts could result in downed trees and broken limbs, electricity outages and blocked roadways. Local flooding is likely in some areas, and “(rapid) rises on creeks and streams are also expected through late week with rises of the mainstem rivers…also expected,” says the NWS website.
Mudslides are also a potential safety threat due to the incoming storm, according to the NWS.
Rainfall is expected to persist through Saturday and Sunday, yet at a much lighter volume.
The City of Morgan Hill and Valley Water have been preparing for potential flooding and stocking up on supplies at sandbag stations in Morgan Hill. The water district’s sandbag station is located at El Toro Fire Station, 18300 Old Monterey Road. The city has an additional sandbag station at its Corporation Yard, at 100 Edes Court.
Available at both stations are piles of sand and burlap bags. Residents and property owners can help themselves to the supplies, which are available on a first come, first served basis. Filled sandbags are sometimes available at the El Toro Fire Station location.
