Temperatures are expected to drop to record lows for this time of year across much of the northern U.S east of the Rocky Mountains. The culprit? A low-pressure mass of Arctic air is making its way down through Ontario, Canada, according to the National Weather Service (NWS).

“Temperatures will be quite chilly for middle May, a good 20 degrees below normal,” on Saturday (May 9), the New York NWS wrote in a Friday forecast discussion. Rain is likely, and flurries are possible, though the mid-May sun makes them unlikely, according to the NWS.

Farther north and…