All indications continue to support the idea of a major temperature pattern flip here in the eastern US beginning late this week (Friday the 13th). One of the contributing factors is the unfolding stratospheric warming events over the polar region that will set off a chain of atmospheric events that will lead to the turnaround. Blocking in the upper atmosphere over the Arctic region is the likely development of this polar event and that, in turn, will allow for numerous and sustained cold air intrusions into the central and eastern US from mid-month on. Along with this significant flip to a cold weather pattern, there will be increasing chances for accumulating snow. Stay tuned.