This climatic convergence is expected to persist through the week, affecting large portions of northern California and the mountainous regions spanning from Washington to Wyoming.

The National Weather Service reports that areas of northern California are set to receive between six to 12 inches of rainfall through Friday. Additionally, heavy snow is anticipated across the Washington Cascades, western Montana, Idaho, and northwestern Wyoming, lasting until early Sunday. These weather phenomena follow the bomb cyclone that recently battered Washington state, where wind gusts peaked at 77 mph inland.

With more than 300,000 customers left without power in Washington state as of early Thursday, per PowerOutage.us, the cyclone's impact has been severe. Tragically, two fatalities were recorded: a woman in Bellevue, Washington, lost her life when a tree fell on her home, and another woman was killed in Lynnwood, Washington, when a tree fell on a homeless encampment.

The ongoing "atmospheric river" storm isn't the only weather system affecting the United States. A second storm system has moved through the central and southern Plains, bringing severe thunderstorms and a tornado in Oklahoma. This system, clashing with arctic air, has generated widespread snow across the Dakotas, Minnesota, and Wisconsin, with near-blizzard conditions reported on Wednesday and potentially into Thursday across the upper Midwest.

In addition, an upper-level low-pressure system is expected to develop over the Great Lakes on Thursday, leading to cooler temperatures, cold rain from the Ohio Valley to the East Coast, and potential snow accumulation in the central Appalachian region. Winter weather alerts are in effect from the mid-Atlantic to the Northeast, with significant snowfall predicted in higher elevations of West Virginia and Maryland.

For the northeastern United States, while most areas will experience rain, some regions are bracing for snow. Portions of northeast Pennsylvania and New York's Catskill mountains could see at least six inches of snow by the week's end.

Forecasters have not yet issued detailed predictions extending beyond seven days, leaving uncertainty about lingering impacts that could affect holiday travel. As nearly 80 million Americans are anticipated to journey more than 50 miles for Thanksgiving next week, according to AAA, extreme weather poses a significant risk of disrupting travel, especially on the expected peak travel days of Tuesday and Wednesday.