A deadly two-day outbreak of tornadoes has killed at least eight people across Michigan and Oklahoma, with millions more at risk of severe weather as storms continue to push eastward this Saturday (March 7).

The National Weather Service (NWS) has warned that about 90 million people from Texas to New York face some risk of severe weather today as a cold front moves through the eastern United States.

Severe thunderstorms that originated in northern Indiana swept into southern Michigan on Friday (March 6), spawning multiple tornadoes across a roughly 50-mile stretch of Cass, Branch, and St. Joseph counties — from Edwardsburg through Three Rivers and into Union City.

Three people were killed and 12 injured near Union Lake in Branch County, according to the Branch County Sheriff's Office. Of the 12 injured, three required hospital treatment. In Cass County, about 50 miles southwest of Union Lake, a 12-year-old boy also died after a possible tornado struck.

Michigan Gov. Gretchen Whitmer said she would declare a state of emergency in Branch, Cass, and St. Joseph counties. The State Emergency Operations Center was activated following the damage reports.

A NWS survey team headed out Saturday morning to assess the damage path, a process that could take up to two days to complete.

On Thursday, a mother and her 13-year-old daughter were killed when their vehicle was struck by a tornado near Fairview in western Oklahoma, according to Major County Sheriff Tony Robinson. Their deaths ended the nation's second-longest streak of 256 days with no reported tornado fatalities in the United States.

Then on Friday evening, a tornado struck a home north-northeast of Beggs, Oklahoma, killing two more people. Okmulgee County Sheriff Eddie Rice confirmed the deaths and said that by late Friday, "all persons are accounted for and there are no more missing persons." Two other people from that home were taken to a hospital.

Emergency manager Jeff Moore said the tornado carved about a 4-mile path of damage through Okmulgee County, toppling large trees and knocking out power near Beggs, roughly 30 miles south of Tulsa.

Oklahoma Gov. Kevin Stitt declared a state of emergency for several counties Saturday morning "to ensure Oklahomans have the support and resources they need after last night's storms," urging residents to report damage and help their neighbors.

The severe weather threat is not yet over. The NWS Storm Prediction Center warned Saturday that parts of the lower Great Lakes and upper Ohio Valley face risks of tornadoes, damaging winds, and large hail. The lower Mississippi Valley and Texas could also see excessive rainfall and flash flooding.

By Saturday evening, storms are expected to push toward the East Coast, from New England down through the Southeast. Additional chances for showers and thunderstorms are possible into Sunday (March 8) and Monday (March 9).

On Sunday, much of the Midwest and Northeast could see temperatures climb as much as 25 degrees above normal, with Pittsburgh potentially reaching the 70s and New York City seeing mid-60s — possibly the warmest day there since early November, according to AccuWeather.