The “arctic outbreak will arrive in the northern Rockies and northern Plains on Thanksgiving into Friday and advance farther south and east through much of the Plains and Midwest this weekend,” according to the National Weather Service. It will come with dangerous windchills, lake effect snow and severe thunderstorms.

Waves of storm systems are expected to move through the East Coast this week, threatening to disrupt some Thanksgiving travel on Tuesday and bringing rain and potentially snow on Thanksgiving Day. Out West, another storm may take aim at California on Monday and Tuesday.