Quite an amazing looking weather pattern is shaping up for the central and eastern US during the next few weeks that will bring bitter cold air masses – perhaps even historic cold in some areas - as well as several storm threats. Temperatures today are below zero throughout a good portion of the Upper Midwest and this Arctic air outbreak is only the first of several that will punish the eastern half of the nation well into the month of January. Temperatures in the Mid-Atlantic region will drop to quite cold levels by New Year’s Day (Wednesday) and then attention will turn to a potential snowstorm in the Northeast US from later Thursday into early Friday. The latest GFS model run (12Z) has shifted to a colder solution than its prior runs as the main upper air feature involved in this upcoming event is now coming into better focus for the computer forecast model. In fact, the GFS model forecast now depicts significant accumulating snow in the Mid-Atlantic region – even as far south as the DC metro region. This scenario looks like a classic setup as it will feature a powerful upper-level jet streak (300 mb forecast map above) with major Arctic air intrusion and a banana-shaped high pressure system sitting to the north. The timetable for this late week event in the Mid-Atlantic region is from later Thursday into early Friday with possibly the brunt of the storm on Thursday night. No matter how much snow falls from this storm, there is sure to be bitter cold air in its wake. In fact, temperatures could drop to 0 degrees in parts of the I-95 corridor by early Saturday morning on top of a fresh snowpack. Furthermore, there are signs for another incredibly cold Arctic air outbreak by the middle part of next week. Stay tuned.