Eastern U.S. braces for flooding while snow will hit Northeast, cold temperatures across Plains

LOUISVILLE, Ky. (AP) - Much of the Eastern U.S. braced for a renewed round of harsh, soggy weather on Saturday, while snowstorms were predicted in the Northeast and heavy winds brought the threat of tornadoes to the Mississippi Valley.

Kentucky, Tennessee, West Virginia and Arkansas were under flood warnings, and residents were warned by the National Weather Service to stay off roads. Parts of western Kentucky could face up to 8 inches of rain.

Gov. Andy Beshear preemptively declared a state of emergency in Kentucky, where flash flooding is expected on Saturday and into Sunday.

"We want to specifically put assets in places that flood and have flooded in the past," Beshear said on social media.

The weather service said flash flooding is possible in the Mississippi, Tennessee and Ohio Valleys. In Tennessee on Saturday, flash flood warnings were alerted in some counties north of Nashville until Saturday evening.

The National Weather Service called the expected rain a “major, potentially historic, flash flood event."

Heavy snow, meanwhile, was expected to blanket much of New England and then transition to sleet, making travel nearly impossible, the NWS said.

In northern New York, heavy mixed precipitation is expected throughout the weekend. Weather forecasters said residents should expect snow, sleet and ice accumulations of six to 13 inches and wind gusts as high as 45 mph (72 kph) late Saturday and Sunday.

"Power outages and tree damage are likely due to the ice and strong winds. Travel could be very difficult to nearly impossible, the NWS said.

Meteorologists warn that the U.S. is about to get its 10th and coldest polar vortex stretching event this season. Weather forces in the Arctic are combining to push the chilly air that usually stays near the North Pole into the U.S. and Europe. The latest projected cold outbreak should first hit the northern Rockies and northern Plains on Saturday and then stick around all next week.

In Denver, where temperatures are expected to dip as low as 14 degrees (minus 10 degrees Celsius) over the weekend, the city has extended its cold weather shelters for those living on the streets. The Denver Coliseum will be opened Saturday for additional space.

In the Rocky Mountains, skiers eager for the long Presidents' Day weekend are already facing a closure on a section of Interstate 70 due to snow as officials warn of hazardous conditions on the mountain roads over the weekend.

Dry weather returned to southern California after the strongest storm of the year but the risk of rock and mudslides on wildfire-scarred hillsides continued Friday since dangerous slides can strike even after rain stops, particularly in scorched areas where vegetation that helps keep soil anchored has burned away.

Water, debris and boulders rushed down the mountain in the city of Sierra Madre on Thursday night, trapping at least one car in the mud and damaging several home garages with mud and debris. Bulldozers on Friday were cleaning up the mud-covered streets in the city of 10,000 people.

A storm in the Sierra Nevada mountains dumped 6 feet (1.8 meters) of snow over 36 hours. Two ski patrol staff from Mammoth Mountain were caught in an avalanche during avalanche mitigation work Friday morning, the resort said in a Facebook post. One was extracted and was responsive, while the other was taken to a hospital with serious injuries.