While the weather pattern will continue to progress to milder conditions in the Central and Eastern states relative to that of early January, chilly air will occasionally fight back in the Midwest and Northeast into next week.
Chilly Air Has Been Stubborn to Leave, Stay Away in Northeast
A dip in the jet stream into the Northeastern states will persist enough to allow waves of chilly air to sweep southward out of Canada into next week. The jet stream is a high-speed river of air high above the ground that guides storms and air masses along across the globe.
According to AccuWeather.com Long Range Expert Paul Pastelok, "Very cold air has been hanging on near Hudson Bay, Canada, and has forced storms to track farther south across Ontario and Quebec."
"There have been more pushes of colder air farther to the south than we first thought in the Midwest and Northeast this week."
Thick snowcover over northwestern Ontario and central Quebec have helped the cold air settle and hold farther south.
Break From Arctic Cold for Some; Thaw for Others
The pattern into early next week will still prevent arctic cold from keeping a steady grip in the Upper Midwest, New England and portions of the mid-Atlantic. Mild Pacific air will stream in from the West into much of the Plains and South.
Compared to temperatures peaking in the single digits and teens in Chicago and the 20s in New York City earlier in January, highs will be 10 to 20 degrees higher over the next week or so.
Highs will average within a few degrees of normal in the swath from the Midwest to the Northeast, which typically range from the 30s in the Ohio Valley to the mid-Atlantic and the 20s farther north. However, this weekend into early next week will bring temperatures spiking to 10 degrees above average or more.
In some cases, ice that has been forming on area lakes and rivers will thin and break up. Ice fishing interests should exercise caution. Where there is substantial snow on the ground, the snow that melts during the day will freeze up at night raising the risk of spotty patches of black ice.
In Minneapolis, Fargo, North Dakota, and Omaha, Nebraska, temperatures through the first half of next week will average 10 degrees above normal, with highs ranging from the 30s in the north to the 40s and near 50 over the central Plains.
Across the South Central and Southeastern states, temperatures will average near normal to 10 degrees above average. Highs will be in the 60s in Dallas, near 60 at times in Atlanta and in the 50s most days into next week around Nashville.
Cold to Come Back Later Next Week, End of January
Cold air will expand southward and westward beginning later next week.
"We expect warmth to build into northwestern Canada during the latter part of January and this will force colder air to push southward into more of the United States," Pastelok said.
There may be a storm or two during the transition, but the track of these storms is uncertain at this time.
Temperatures during the latter part of January into early February will average below normal a substantial amount of the time for most areas east of the Rockies.