Another Cross-Country Winter Storm

Another storm system could bring snow and some ice across the country late this week. This follows on the heels of Winter Storm Caly, which has affected the U.S. with wintry weather from coast-to-coast the last few days, including the Pacific Northwest, Midwest and Northeast regions. Given the very cold temperatures that are expected across the northern tier of the U.S. this week, wintry precipitation could be a concern in many locations with this next system, from the Sierra Nevada to the Rockies, Plains, Midwest and parts of the East.

This next storm will get its start as a southward plunge of the jet stream, originating from the Gulf of Alaska, begins to plow into the western United States.


Late-Week Forecast
Cold air is in place across the Midwest and East with high pressure in store. A storm system sweeping into the western states then moves eastward into the cold air, making wintry weather possible. Energy in that jet-stream dip will eventually spawn an area of surface low pressure in the Plains, which will track northeastward with time through the central and eastern states. Moisture from that system will overlap with cold air to its north and from high pressure in the eastern states to make conditions ripe for the potential of wintry weather in a large area.

Thursday

The larger-scale jet-stream dip will then plow into the West Coast starting Thursday. Snow is expected from California's Sierra Nevada north and eastward into Oregon, southeast Washington, Idaho, Montana, northern Nevada, Utah and the Colorado Rockies. Lowering snow levels can be expected as the storm system moves farther inland through Friday.

Friday

The storm may spread its reach into the northern Plains, upper Midwest and Great Lakes Thursday night through Friday. Snow and strong winds are possible in those areas. Blowing snow could create low visibility and dangerous travel conditions. As milder air overruns cold air near the surface of the earth, a wintry mix and some ice could affect the central Plains and mid-Mississippi Valley.

Friday Night

By Friday night or Saturday, moisture from this system may overrun cold air from a retreating area of high pressure in the eastern states. This would result in a wintry mix and possibly some ice affecting the Ohio Valley, Appalachians and mid-Atlantic.