Also, heavy snow for the Cascades and the Northern Intermountain Region.
Winter weather advisories and heavy snow warnings for parts of Wyoming, Nebraska, Kansas, Colorado, North Dakota, South Dakota, Missouri, Indiana, Illinois, Minnesota, Oregon, Washington, Idaho and Montana.
Whoa! That’s 17 states! Ain’t global warming a bear?
Tue Dec 29 2020- A strong storm over the Central Rockies moving northeastward to Eastern Canada by Thursday morning will produce snow over parts of the Great Basin, Southwest, Central/Southern Rockies, and the Central/Northern Plains on Tuesday, which will move into the Upper Mississippi Valley/Upper Great Lakes, and Western Ohio Valley by Tuesday evening.
An area of rain/freezing rain and sleet will develop over parts of the Central Plains, moving into parts of the Middle Mississippi Valley, likewise by Tuesday night. The rain will change over to snow over parts of Western Texas late Wednesday afternoon, continuing into Thursday morning.
On Wednesday, rain and snow will move into parts of the Northeast.
There is a large area of Winter Weather Advisories and Winter Storm Warnings over the Plains into the Midwest on Tuesday into Wednesday. The snow and rain/freezing rain will produce hazardous driving conditions.
Snowfall amounts of 6 to 8 inches will develop over parts of Iowa into Southern Wisconsin and parts of West-Central Michigan. Meanwhile, a front will move onshore over the Pacific Northwest on Wednesday into Thursday. Onshore flow associated with the boundary will stream moisture into the Northwest from the Pacific. Late on Tuesday, rain will start to develop over parts of the Pacific Northwest and snow at higher elevations. By Wednesday, snow will move into parts of the Northern Intermountain Region.
Later on Wednesday, coastal rain and higher elevation snow will move into parts of Northern California.
By Thursday, snow moves into parts of the Great Basin. Snowfall amounts will be 12 to 18 inches over the Cascades and about 12 inches over parts of the Northern Intermountain Region.
The snow will produce hazardous driving conditions.
Short Range Forecast Discussion NWS Weather Prediction Center College Park MD