The eastern two-thirds of the nation recently experienced a blast of bitter cold air, setting record lows in various places. Dillon, Montana, recorded its all-time low of minus 41 degrees, while the NFL’s Kansas City Chiefs and Miami Dolphins played their coldest game in franchise history at minus 4 degrees. Despite this extreme cold, another blast of cold air is expected to move through the Plains and Mississippi Valley, lingering in the Southeast over the weekend.

Although not as severe as the previous cold spell, this upcoming blast will still bring uncomfortable temperatures. Parts of the Missouri Valley may see lows in the 20s below zero, potentially setting daily record lows. The Southeast may struggle with highs in the 20s, setting daily cold high records.

The forecast indicates a thaw beginning early next week, with milder air moving north into the Plains, Midwest, and the South. By Monday and Tuesday, temperatures will rise, reaching the freezing mark in the upper Midwest and 50s and 60s in the South. Much of the South is expected to experience 60s and 70s by mid-week. This January thaw may persist through the rest of the month, although some colder air could return to parts of the East around early February.

However, the thaw won’t be without its challenges. Warmer, more humid air over existing snowpack could lead to fog and low clouds in the Midwest, South, and East. Precipitation, turning more into rain due to milder temperatures, is expected in the southern Plains, Midwest, and Northeast. This combination of warmer air and rain may lead to melting of snowpack, potential flooding, and ice jams in rivers and streams.

The shift in weather patterns is attributed to the disappearance of blocking high pressure near Greenland and the Canadian Arctic, allowing milder air from the Pacific Ocean to dominate. This reversal prevents the mechanism that forces cold air from Canada into the U.S., trapping colder air in Canada for a while.