A second winter storm brings cold, rain and snow to millions

The most significant winter storm this year for California is making its way to fire-ravaged communities of Southern California, and threatens to bring potentially deadly, “raging torrents of rockslides and mudslides,” according to National Weather Service forecasts. Meanwhile, millions of Americans across the country faced various threats of heavy snow, wind, extreme cold and tornadoes.

Rain arrives on the West Coast Wednesday with heavy downpours expected late overnight in Central California and moving down to Southern California by Thursday.

“The heavy rain may cause flooding in urban areas and small streams, as well as some minor river flooding,” the National Weather Service’s Weather Prediction Center said. The WPC issued a “Slight Risk” warning for excessive rainfall over Central California to last through Thursday morning.

The risk of flash flooding is highest for communities in or near recently burned areas. Ahead of the storm, wildfire clean up crews worked at “unprecedented” speed to remove structural debris from the destructive Eaton and Palisades fires, according to California Gov. Gavin Newsom’s office.

“It’s possible we get through this rain event without any significant problems, but the potential is there,” said Ariel Cohen, meteorologist in charge at the National Weather Service in Oxnard, according to LAist.

Elsewhere in the nation, wild winter weather threatened Americans from the Midwest to the mid-Atlantic. Communities in Washington, D.C., were digging out of several inches of snow Wednesday morning, while a second winter storm was bringing more snow to the Central Plains into the Great Lakes and a combination of snow, ice and sleet just to the south. Heavy rain and potentially dangerous thunderstorms are also expected to hit parts of the Lower Mississippi Valley and the Southeast, according to the National Weather Service. 

Flash flooding and mudslide risks

Between 2 p.m. Thursday and early Friday morning the rain is expected to be the heaviest with rates that could reach 1 inch per hour. The “strong plume of moisture” bringing the wet weather to the West Coast is expected to intersect with the central and southern Sierra Nevada ranges Thursday into Friday, bringing multiple feet of snow.

Even years after a wildfire, areas charred by intense flames can make soil repel water — similar to when rain hits pavement, according to the California Governor’s Office of Emergency Services. Consequently, much less rain is needed to create a flash flood, increasing the potential for mudslides and other debris flows.

The disastrous Eaton and Palisades fires burned thousands of acres of land in Southern California and were only fully contained at the end of January. Those areas burned by the fires and locations situated downhill and downstream from those neighborhoods are especially vulnerable to the coming rain and possible subsequent mudslides.

Officials ahead of the rain urged residents to prepare to evacuate those vulnerable areas. The Santa Barbara County Sheriff’s Office has already issued an evacuation warning for neighborhoods in and near the Lake Fire burn scar.

Snow and tornadoes

Chicago and other parts of Illinois were hit with heavy snow accumulation by Wednesday afternoon in a storm that’s expected to bring the city’s most substantial snowfall so far this season, according to the National Weather Service. This storm is expected to drop around 6 inches of snow in Chicago and 5-9 inches in the Milwaukee area.

“Bursts of heavy snow, accumulating at times to an inch per hour, may lead to hazardous driving conditions and disrupt travel. Heavier snow rates should develop in time for the evening rush hour in Milwaukee, Chicago, Grand Rapids, and Detroit, among other locations,” the NWS cautioned. “Further, a wintry mix of snow, sleet, and freezing rain on the south side of the main snow band will lead to hazardous travel conditions elsewhere in the Midwest and Northeast.”

The skies may be flurry free in the Plains, but the NWS issued serious warnings for parts of Montana, North Dakota and Idaho lasting until Thursday morning with expected overnight wind chills between 45 to 55 degrees below zero. Temperatures that cold could cause frostbite on exposed skin in as little as five to 10 minutes, the NWS warned.

As this storm passes through the Midwest overnight, it’s expected to continue its move further East, bringing close to five inches to a foot of snow to parts of upstate New York and northern New England.

Meanwhile, rain and serious thunderstorms threatened residents in the South. Severe weather is predicted for Southern Louisiana and Western Georgia, according to the NWS’ Storm Prediction Center. An “enhanced risk (level 3 of 5)” was issued for the southern half of Mississippi and Alabama as the potential for large hail, severe winds and tornadoes (including possible EF2 or greater) were heightened.