Weather highlights over the United States early in the week will contrast widely from west to east. Whereas record highs will be topped under bright sunshine in many Western states, a shot of chilly to cold air will make its way out of the Midwest and into the East.

Let's fast forward to Thursday and Friday. At this time, a northward bowing of the jet stream over the Eastern states will coincide with its southward buckling in the West. Unusual warmth will break out from the Mississippi Valley to the Eastern Seaboard. At the same time, chilly air will dip southward over the West Coast through the Rockies accompanied in some areas by rain and even snow.

Story by AccuWeather.com Senior Meteorologist Jim Andrews.