After several days of unseasonable warmth, bitter cold and snow will spread across the Western and Central states late this week into this weekend.
Right on cue, snow, ice and cold will arrive in conjunction with the winter solstice, which is this Saturday.
Snowfall amounts of 3-6 inches are expected across portions of Utah, Wyoming and western South Dakota through Friday as a storm system moves through the region.
This will likely cause slick roads and travel delays, especially on Interstates 80, 15, 25 and 90.
Reduced visibility and deicing operations will cause some flight delays at the airports, including Salt Lake City, Utah, and Rapid City, S.D.
Many locations across the central Plains will be at least 30 degrees colder Thursday compared to Wednesday.
After reaching 60 degrees Wednesday, the high in Rapid City, S.D., Thursday will be nearly 40 degrees colder.
"Temperatures have taken a roller coaster ride in the West this month," said AccuWeather.com Senior Meteorologist Danny Pydynowski.
"This recent warm spell followed the frigid start to December in the Plains and Rockies and temperatures are heading downward once again," Pydynowski added.
Big temperature changes are also expected across Southern California and the Southwest, where record highs were toppled earlier in the week.
After an early-week stretch of days with highs in the 80s in Los Angeles, temperatures may not reach 60 degrees Thursday.
A stronger storm will bring a mix of snow and ice and more travel problems this weekend from the southern Plains to the Midwest.
The timing of this storm will wreak havoc for folks planning to leave home over the weekend for the Christmas holiday, as there will be travel delays on the roads and at the airports.
There is the potential for several inches of snow in Wichita, Kan., Kansas City, Mo., Moline, Ill., and Milwaukee, Wis., while Chicago and Detroit, Mich., will get a mix of snow and ice.
Frigid air will persist this weekend in the northern Plains with the cold air also spreading into the Midwest.
Record-shattering warmth is likely ahead of this storm system from the Southeast to the mid-Atlantic this weekend, along with the threat for flooding rain and intense thunderstorms.