By Allison Chinchar, CNN Meteorologist
As millions of Americans gear up to travel this Thanksgiving holiday week, forecast models continue to show a temperature roller-coaster and a potent storm this week.
Starting Sunday, several states will face snow, ice and dangerous winds. And a secondary system will bring additional travel troubles for the middle of the week.
Traveling by airline for the holiday? You may be in for a bumpy ride as well as delays.
Here is the day-by-day breakdown.
From the Great Lakes down to the Gulf Coast, rain will be the primary threat, though snow showers will mix in at times in areas of the upper Midwest.
“A potent cold front delivers a shot of considerably colder temperatures across the Midwest and Great Lakes late Sunday into Monday, causing heavy lake effect snow showers to breakout downwind of the Great Lakes on Monday,” the Weather Prediction Center (WPC) said Saturday. “Ahead of the storm system’s cold front, numerous showers are forecast to breakout from the Deep South to the northern Mid-Atlantic Sunday afternoon. Expect these showers to reach the Northeast and extend as far south as the Southeast Sunday night.”
All that rain in Detroit, Milwaukee, Cincinnati, Atlanta, Memphis and Pittsburgh may lead to some airport delays as well as traffic jams on interstates and highways.
Overall, rainfall accumulations are expected to be around 1 inch or less, but some isolated spots could pick up as much as 3 inches.
“Heavy rain and isolated instances of flash flooding possible across portions of eastern Florida and South Texas today,” the WPC said Sunday morning.
On Sunday, strong winds begin to kick up in the Northern Plains, shifting to the Midwest by Monday. This could lead to significant airline delays as well as very bumpy flights over some locations.
On Monday, the cold front will extend from Maine to Florida, with rain and wind posing the main threats.
Cleveland, Syracuse and Buffalo, New York, will have snow in the forecast along with gusty winds.
“Rain will transition to rain and snow showers Monday behind a strong cold front,” the National Weather Service office in Buffalo said in a hazardous weather outlook. “Lake effect snow will then develop Monday night through Tuesday. Several inches of accumulation are likely in the most persistent lake snows.”
While Chicago, Milwaukee and Detroit will begin to dry out Monday, very gusty crosswinds of 20-35 mph could lead to flight delays. Even cities as far south as Knoxville, Tennessee, and Atlanta could be looking at gusty winds on Monday.
“Pilots will be looking for the smoothest air to fly in, but many passengers are sure to hear ‘Ladies and gentlemen, please keep your seat belts securely fastened,'” said CNN meteorologist Chad Myers.
Monday, Tuesday and Wednesday will bring high winds to the Northeast, potentially causing some flight delays in Boston, New York and Washington, DC.
Monday also marks another big day of temperature swings across the country.
Temperatures in much of the Midwest and Ohio River Valley will be well below normal. Cincinnati, Indianapolis, Detroit, Nashville, Tennessee, and St. Louis will all have high temperatures 10 to 15 degrees below seasonal averages.
The above-average temperatures will be limited to the area from Denver to the Canadian border, where high temperatures will be 15 to 20 degrees above normal.
By Tuesday, lingering snow showers will remain along the eastern Great Lakes, as a new low-pressure system pushes into the Mountain West. This storm will become the focal point of travel troubles in the Midwest on Wednesday.
Thanks to the system from the previous day, the Northeast will continue to deal with rain, snow and gusty winds that could make roadways and runways a mess.
“Potential heavy rainfall for portions of the Southern Plains and Lower Mississippi Valley may impact travel for the Thanksgiving holiday,” the WPC said.
Keep in mind there is still enough uncertainty in the evolution of this system to allow for other types of precipitation. If temperatures are warmer by just a few degrees, it will mean the difference between snow and rain for several states.
Mother Nature might also be getting her holidays confused thanks to big swings in temperatures.
From Boston down through Jacksonville, temperatures on Tuesday will average 10 to 15 degrees below normal, making it feel more like Christmas than Thanksgiving.
The Intermountain West and High Plains regions will see the opposite effect. From Amarillo, Texas, to Bismarck, North Dakota, temperatures will be 15 to 30 degrees above normal Tuesday, resembling Halloween temperatures more than Thanksgiving.
As the next system begins to push into the Pacific Northwest, Seattle and Portland, Oregon, will likely pick up 1 or 2 inches of rain.
Wednesday provides a bit of a break for the Southeast, but windy conditions become the focus for a huge swath, from Michigan to Texas.
Chicago, St. Louis, Dallas and Oklahoma City will likely deal with blustery winds of 20 to 30 mph throughout the day.
The secondary system will shift into the Midwest late Wednesday. Rain, snow and even ice are possible for Michigan, Wisconsin and Illinois, which could be very dangerous for both road and air travel.
Finally, a new system will begin to enter the Mountain West. Snow showers are possible for Denver and Salt Lake City.
“Across the northern tier, the combination of low temperatures and wind would produce cold wind chills,” the WPC said.
Thanksgiving could feel more like Christmas
A cold front will bring rain showers from Texas to Ohio, along with some snow showers for Michigan, Wisconsin and Minnesota.
Temperatures rebound mostly back to normal by Thursday for much of the eastern half of the US, but keep in mind that “normal” can still be cold.
New York will likely see temperatures in the low 40s, so for anyone that might venture out to watch the big morning parade, make sure you bundle up!
What about the return home? While it is too far out to get a really good handle on the forecast for the weekend after Thanksgiving, two areas look to have more potential than others for dicey travel: the Pacific Northwest and the Gulf Coast region.
™ & © 2021 Cable News Network, Inc., a WarnerMedia Company. All rights reserved.
CNN Meteorologist Judson Jones contributed to this story.