...Slight risk of severe thunderstorms for portions of the Mid-Atlantic
...Late season snow is forecast over the Upper Great Lakes...
...Temperatures will be 10 to 20 degrees below average from the Upper Great Lakes to the Tennessee Valley...
...On the other hand, temperatures will be 15 to 25 degrees above average for the Northern Rockies/High Plains and the Northern Intermountain Region...
A reinforcing front, extending from the Great Lakes to the Southern
Plains, will catch up to the lead front, extending from the Northeast
southwestward to the Eastern Gulf Coast by Sunday morning.
The main boundary will move off the East Coast by late Sunday afternoon, while lingering over Southern Florida through Monday morning. Late season snow is forecast over the Upper Great Lakes through Sunday evening. Late season snow will also develop over parts of the Northern Appalachians on Monday morning too. In addition, rain will develop over parts of the Great Lakes into parts of the Ohio/Tennessee Valleys on Saturday evening moving into the Lower Great Lakes by Sunday evening.
Showers and thunderstorms will develop along and ahead of the main front from the Northeast to the Central/Eastern Gulf Coast moving off the East Coast and the Gulf Coast by Sunday afternoon. An area of light to moderate rain will develop over parts to Eastern Maine on Sunday afternoon, waning to light rain by Sunday evening.
Behind the system high pressure will sink southward out of Central Canada to the Central Gulf Coast by Monday. Clockwise flow around the high will stream moisture into Southern Texas and Northeastern Mexico producing showers and thunderstorms over parts of Southern Texas through Sunday evening.
Meanwhile, a front over the Eastern Pacific will move onshore over the
Pacific Northwest early Sunday morning producing light rain over parts of the Northwest late Saturday night into Monday morning. The rain will be light to moderate over some of the higher elevations.
A warm front associated with the system will move into the Northern Plains Sunday night into Monday morning, triggering light rain over parts of the Upper Mississippi Valley on Monday morning.