Metro Detroit will see a White Christmas -- but with it an introduction of cold air that will stick around all week.
According to the National Weather Service, Sunday will bring most of the snow. A winter weather advisory initially forecast to end at 10 p.m. has been extended to midnight. Snowfall estimates have also been bumped up to five to seven inches, from the three to four inches foretasted earlier Sunday.
"We will see snow," said weather service meteorologist Alex Manion.
Manion said the snow results from a low pressure system passing through the Ohio Valley to the northeast that will bring moisture to "a solid swath of Southeast Michigan."
That snow will be on the ground Christmas morning, but more is not expected to fall until later in the morning. High temperatures will hit the low to mid 20s, and Monday is the start of "an extended period of below normal temperatures," for December, Manion said, in which high temps aren't expected to crack the 20s until Friday.
Monday will also be windy, with wind speeds of 20 to 30 miles per hour possible.
"It's going to be fairly uncomfortable outside," Manion said.
Monday also brings the potential for snow squalls, fast-falling flashes of snow, lasting about 20 to 30 minutes, that can be dangerous for drivers.
In December 2016, the whiteout caused by snow squalls was cited by authorities as a factor in a 53-car pileup in Livingston County that left three people dead.
The Christmas Day snow squalls are expected to fall in the area between Interstate 94 and Interstate 69, sometime in the early afternoon.
Overnight going into Tuesday, lows should fall to the upper single digits or low teens, while wind chills could hit the low single-digits.