Temperatures dropped sharply in Southern California on Monday, with wet conditions expected throughout the week, while a powerful winter storm began hitting Northern California late Monday, bringing several inches of rain and high winds.
An atmospheric river, or weather system that moves high concentrations of water vapor out of the tropics, could bring 1 to 3 inches of rain to coastal areas and 3 to 5 inches more to higher elevations Tuesday, The National Bureau of Meteorology told CBS San Francisco. Atmospheric rivers may be class 4 in intensity and up to class 5 in scale.
A raging jet stream pushed a powerful winter storm system into California’s Bay Area on Monday amid a series of weather warnings, CBS San Francisco report. The National Weather Service issued a series of updated warnings for communities in the area, including flood advisories for the cities of San Francisco, Watsonville, Pacifica, Santa Cruz, Scotts Valley and Boulder Creek. The warnings went into effect late Monday night and are currently in place until Tuesday afternoon.
By Tuesday morning, experts were predicting significant runoff from surrounding mountains could flood rivers, creeks, streams and low-lying areas, the Bureau of Meteorology said in an advisory, adding that flooding was likely in urban areas and deprived areas drainage system. Storm drains and ditches could become clogged with debris, the weather service warned.
NOAA
“The favorable peaks and higher elevations of the Sonoma Coastal Mountains could see localized rainfall of up to 7 inches, where moderate to heavy precipitation is currently expected to continue with increased rainfall,” the NWS told CBS San Francisco. “Last but not least, if that wasn’t enough, the thunder could spread as far south as near San Francisco. Expect only rumbling thunder here and there.”
A flood watch is in place for the North Bay, San Francisco and the coastline, the National Weather Service said. Wind advisories were also issued along the coast from Sonoma County to Santa Cruz County.
The agency’s San Francisco bureau shared updated guidance early Tuesday, noting that “moderate to heavy rain” is expected throughout the day, with 5 inches expected locally and 2 to 4 inches expected along the coast. Inland areas are expected to receive between 2 and 3 inches of rain, the weather service said, with valley communities expected to see slightly less rainfall. The announcement is scheduled to be effective until 6 p.m. PST Tuesday evening.
“Localized flooding is possible, especially in urban areas where flooded or poorly drained roads are a common problem,” Weather Service forecasters said. Flooding. Commuters should plan a wet trip on Tuesday and allow more time to get to their location.”
Wet weather Monday night has caused traffic problems for BART trains across the Bay Area, the agency reported at the time, saying transit passengers should brace for system-wide delays of up to 20 minutes. According to CBS San Francisco, the weather service said that around 5:50 p.m. Monday, the area around the San Francisco airport began to rain.
The Weather Service also issued a wind advisory for coastal communities from Sonoma County to Santa Cruz County, which went into effect late Monday night and is scheduled to remain in place through Tuesday morning.
“Southerly winds of 20 to 30 mph are expected, with gusts of up to 50 mph expected,” the Bureau of Meteorology said. “On ridges and peaks, local wind gusts up to 60 mph.”
California officials warned of downed trees and branches and possible power outages due to forecast winds, citing “hazardous swimming and surfing conditions,” CBS San Francisco reported.
Meanwhile, in Southern California, the National Weather Service is forecasting a dramatic change in weather, with temperatures dropping into the low 20s as the storm system sweeps through the region.
“Farewell to Warmth,” NWS Los Angeles tweets. “Significant drop in track temperature between today and tomorrow (Tuesday). 15-20 degree drop expected due to the upcoming storm system”
Temperatures in downtown Los Angeles are expected to drop from a high of 79 degrees on Monday to 61 degrees on Thursday, according to the NWS. CBS Los Angeles report.
According to the National Weather Service, the developing low pressure system will move across Washington late Tuesday and pull a stream of very humid air over California early Tuesday and early Wednesday.
The NWS said the plume will slowly move through San Luis Obispo and Santa Barbara counties throughout Tuesday, bringing 1.5 to 3 inches of rain, with up to 5 inches in the foothills such as the San Lucias.
Ventura and Los Angeles counties could see half an inch to an inch of rain within four to six hours, the NWS said.
Meanwhile, northwestern Oregon and southwestern Washington are facing a storm system that is expected to bring heavy rain and strong winds beginning Monday night that could cause minor flooding of rivers and creeks, according to NWS Portland.
“A powerful frontal system could bring heavy rain and strong winds to northwestern Oregon and Western Australia on Tuesday,” NWS Portland tweets“Coastal winds strongest, strengthening tonight into Tuesday. Windy inland Tuesday morning and late afternoon.”
Weather shifts as millions of Americans grapple with colder weather winter storm This has swept through much of the United States.
CBS News confirmed that at least 62 people across the country were killed by the storm.
The storm’s scope is almost unprecedented, stretching from the Great Lakes near Canada to the Rio Grande River on the border with Mexico. About 60 percent of the U.S. population is facing some kind of winter weather advisory or warning, with temperatures dropping sharply below normal from east of the Rockies to the Appalachians, the National Weather Service said.
Thousands of U.S. flights were canceled Saturday, with nearly 3,000 canceled as of Sunday night, according to tracking site FlightAware.