BY LINDA LAM, The Weather Channel
A significant cooldown has swept into parts of the Midwest and Northeast, so hopefully you haven't put away your jacket yet after enjoying a taste of spring last week.
This flip to a cooler temperature regime is due to an upper-level trough that has dipped southward into the Midwest, dragging modified Canadian air from the northern Plains to the Northeast. This upper-level trough will make slow progress eastward which will allow the cool temperatures to remain in place.
The air mass has even been cold enough for snow in some locations.
As of Wednesday night, up to 12 inches of snow was reported in Bessemer, Michigan. Some higher terrain locations in western Pennsylvania, western Maryland and northern West Virginia have also seen a few inches of snow.
Meanwhile, parts of North Dakota woke up to temperatures in the teens Wednesday morning. Daily record lows were set Wednesday in Pierre, South Dakota (19), Aberdeen, South Dakota (15), and Sioux City, Iowa (24). Wednesday's high in at the National Weather Service office outside Marquette, Michigan in Negaunee Township (26) was the coldest so late in the season, there, more typical of high temperatures in mid-February.
How Cool Will It Be?
For some locations, highs may not get out of the 30s and 40s at times this week. Let's look at the forecast details below.
Thursday: Afternoon temperatures will be below average in most locations from the Northeast into the Upper Midwest. Highs in parts of the northern Great Lakes may again struggle to rise out of the 30s. Much of the eastern Great Lakes and Upstate New York may not get out of the 40s.
Friday: Freezing warnings and frost advisories are posted for Friday morning in parts of the Ohio Valley, Appalachians and Mid-Atlantic.
(MAP: Frost/Freeze Alerts)
Cooler-than-average temperatures will persist from the Great Lakes through the Northeast I-95 corridor. Highs will likely hold in the 50s once again from Boston to New York City and Philadelphia. Portions of the interior Northeast and northern Great Lakes will see highs in the 40s once again.
Saturday: The weekend starts with below-average temperatures from the Great Lakes to the Mid-Atlantic. Highs will be in the upper 50s and low 60s from Boston to Washington, D.C. In the Great Lakes, Chicago and Toledo, Ohio will see high temperatures hold in the 40s.
Sunday-Monday: Temperatures will slowly retreat to levels near or slightly below average to start next week in the Great Lakes and Northeast.
(MAPS: 10-Day Forecast)
Meteorologists Chris Dolce and Jonathan Erdman contributed to this report.