AccuWeather reports following mild, wet weather to end this week, progressively colder air will unleash rounds of lake-effect snow from the Upper Midwest to the interior Northeast for travel during the week of Thanksgiving.
Travel delays related to wind and/or snow are likely in parts of the midwestern and eastern United States.
"We expect two major pushes of cold air into the eastern half of the U.S. during the week of Thanksgiving," according to AccuWeather Long-Range Meteorologist Evan Duffey.
The weather pattern is giving mixed signals as to whether or not a storm will bring rain and snow to the East during the transition to the cold weather.
However, there will be a consequence as reinforcing waves of cold air pass over the Great Lakes.
As cold air passes over the relatively warm waters, streets of towering clouds form and deposit heavy snow along the downwind shoreline and dozens of miles inland.
Where the bands of heavy snow persist, up to a foot of snow can fall. As many as two rounds of lake-effect snow are anticipated from Sunday through the Thanksgiving weekend.
The details of which communities will be hit the hardest on particular days has yet to be determined. A small variance in the wind direction can vary the bands of heavy snow by a dozen miles or more.
For example, a west-southwest wind off Lake Ontario would blast Watertown, New York, with intense snow, but a due west wind would potentially bury communities such as Barnes Corners and Sandy Creek, New York, several miles to the south.
"Motorists with plans on utilizing Interstate 90 from northern Indiana to western New York, I-81 in northern New York state and other highways immediately downwind of all of the Great Lakes should be prepared for travel delays and rapid changes in roadway visibility next week," according to AccuWeather Meteorologist Steve Travis.
One round of lake-effect snow associated with the first cold blast will erupt later this weekend into early next week.
Another round of lake-effect snow may begin during the middle of next week. There is still uncertainty as to the extent or intensity of that round of lake-effect snow.
Travel conditions will range from blinding snow and the potential for temporary road closures to sunny over a span of a few miles.
At times, the bands of lake-effect snow may extend 200 miles or more to the central Appalachians. Motorists traveling through the higher terrain in West Virginia, western Maryland and western and northern Pennsylvania should expect locally blinding snow squalls and a quick accumulation on roads. This includes stretches of I-79 and I-80.
At times, wind gusts may be strong enough to lead to difficulty for high-profile vehicles. Strong crosswinds at airports from the Midwest to the mid-Atlantic coast can lead to airline delays in lieu of any snow or a major storm.
Gusty winds to add to the pain of the cold air
"Blasts of cold air like this are not uncommon during the middle and latter part of November," Duffey said. "However, following the warmth during most weeks of this autumn season, heating demand will be high."
Temperatures are projected to average 5-10 degrees Fahrenheit below normal during multiple days during the week of Thanksgiving from the Midwest to the Northeast, as well as much of the Southeast.
The anticipated weather pattern will translate to highs in the 20s over the northern tier to the 40s over the interior South on the coldest days. AccuWeather RealFeel® temperatures can dip to 20 degrees lower than the actual temperature at times.
Battling the wind on the highway may reduce fuel efficiency.
Regardless of wind, motorists can expect to pay much more at the pump for their Thanksgiving road trip. Strong consumer demand and lowering national inventory have pushed gasoline prices to nearly 40 cents a gallon higher than last year at this time, according to the American Automobile Association.
One positive of the cold weather pattern will be plenty of opportunities for ski resorts to make snow in the days leading up to Thanksgiving.
What about the storm potential?
In terms of large-scale storms that may increase commute time, one storm projected to affect much of the eastern U.S. this weekend will likely be warm enough for rain in most areas and even gusty thunderstorms in part of the Midwest.
However, it is the same storm that will set into motion the first blast of cold air for next week.
"A second storm during the middle of next week has the potential to bring a period of rain along the Atlantic coast and snow over the Appalachians spanning Wednesday to Thanksgiving Day," according to AccuWeather Chief Meteorologist Elliot Abrams. "Another scenario is the second storm may be so overwhelmed by cold, dry air that it is forced out to sea."
Regardless of the nature of the storms, gone are the warm and tranquil conditions that graced much of the Midwest and East during October.
Motorists and airline passengers should anticipate delays and be ready to adjust their travel plans during the week of Thanksgiving.