(CNN) -- Yes, Easter was more than a week ago. Yes, it officially became spring almost three weeks ago. And yes, blizzard conditions are still in the forecast in parts of the continental United States.
A major winter storm was developing over the western Plains on Monday evening, promising "a plethora of interesting weather conditions," The National Weather Service's Weather Prediction Center said.
"Blizzard conditions are likely over parts of Wyoming, Colorado, western Nebraska and western Kansas" beginning late Monday and lasting through much of Tuesday, the weather service said.
The Denver metro area could see as much as a foot of snow, and the foothills and mountains can expect even more than that. High winds caused flight delays of up to 40 minutes at Denver International Airport Monday, and some flights were diverted to a Colorado Springs airport, according to the Denver airport.
Denver International is preparing for 5 to 8 inches of snow and reports 26 flight cancellations, it said.
Farther east and south, more typical spring storms -- meaning possible severe thunderstorms with hail, heavy rain and gusty winds -- were expected to visit the southern Plains and Mississippi River Valley by Wednesday evening.
The bad weather isn't all wet. The weather service issued a blowing dust advisory Monday for Arizona.
Meanwhile, the Ohio Valley, Mid-Atlantic and Southeast states should expect unseasonably warm air to linger until late in the week, while it should remain relatively cool in the Northeast and Great Lakes region.