A “bomb cyclone” in the Pacific Ocean on Sunday will trigger more than a foot of rain in drought-stricken parts of California and up to 8 feet of snow on the mountains, forecasters say.
Much of the west coast is starting to feel the effects of the deepening low pressure system off the Pacific Northwest, the National Weather Service’s Weather Forecast Center said on Sunday. A bomb cyclone forms when atmospheric pressure drops rapidly as the storm explosively strengthens.
“Conditions will continue to deteriorate as the system approaches,” the center tweeted. “Strong winds, heavy waves and heavy rains will cause major impacts. Heavy snowfall in the Sierra from tonight.”
The region needs rain. Gov. Gavin Newsom declared a state-wide drought emergency last week, citing three years of drought in the West.
Seventeen large forest fires are burning in California, Idaho, Montana, Oregon and Washington, according to the National Interagency Fire Center. Wildfires have burned nearly 2 million acres in California in 2021 alone. Storms will effectively end the wildfire season in much of the region, said AccuWeather meteorologist Jon Carry.
“This precipitation comes about a month ahead of average and will be welcome in fighting the remaining fires, particularly in northern California,” Porter said.
‘Flood’ in times of drought: Millions of Californians were warned of flash flood risk on Sunday
The bomb cyclone was to draw deep tropical moisture from the Pacific, creating an “atmospheric river”. Porter describes an atmospheric river as a “moisture-in-the-sky fire hose,” capable of unleashing heavy rain and mountain snow.
Moisture from the developing atmospheric river is targeting northern and central parts of California as well as parts of southern Oregon, with the greatest intensity this morning through Monday, he said.
Rainfall of up to 2 inches per hour can be “too fast and too violent”, leading to severe flooding and mudslides that could threaten lives and property, Porter added.
Governor Gavin Newsom declares drought emergency in California, calls for statewide conservation
The National Weather Service Bay Area issued flash flood alerts, tweeting: “The main concern will be the 2020 burn scars, but urban and small stream flooding is likely as the strip of heavy rain passes through. Sunday afternoon and night. “
The National Weather Service for Sacramento has issued a flash flood and debris flow warning for the now 97% contained Dixie blaze, but a blaze that has burned nearly a million acres since it s ‘was lit more than three months ago.
“Heavy rains are starting to arrive and this will cause debris flows,” the weather service warned. “If you live near a recent burn scar, now is the time to prepare and listen to local authorities for any evacuation information.”
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