Coldest air of winter to arrive this weekend
A large arctic airmass, owing to a piece of the polar vortex, will drop southward late this week and weekend from Canada into the Great Lakes and Northeast United States. With it will come the coldest air of the winter — and the coldest air in quite some time, especially aloft. Temperatures at 850mb, or roughly 5000 feet, will drop to nearly -30 degrees celsius, challenging some records for temperatures at that level in the Northeast US for the date.