...Temperatures will be 25 to 35 degrees below average over the Upper Midwest to the Ohio Valley/Great Lakes...
...Sleet and snow for parts of southeastern Texas by Tuesday morning...
A clipper system along the leading edge of significantly cold air mass
will move rapidly northeastward to Southeastern Canada by Monday night. The associated cold front will race off the East Coast and Gulf Coast also by Monday night.
The system will produce light snow from parts of the Northeast/Great Lakes to parts of the Middle Mississippi Valley ending over Northern New England overnight Monday.
Behind the system, lake effect snow will develop downwind of the Great Lakes on Monday evening, reducing to a plume across parts of the Upper Great Lakes on Tuesday morning.
A cold area of high pressure over West-Central Canada will move southward to the Ohio Valley by Tuesday.
As the high descends southeastward, clockwise circulation around the high will produce upslope flow, which in turn will develop light snow over parts of the Northern/Central Rockies through Monday evening.
On Tuesday, upper-level energy and upper-level jet dynamics will aid in produce sleet and snow over parts of southeastern Texas. The energy will also produce light snow over parts of Western Oklahoma.