Daniel Schaefer

Average first accumulating snow dates are right around the corner! However, it appears some areas may see their first accumulating snow later than average this year. Much of the purple-shaded area is trending toward the middle of November rather than early in the month. For areas farther south, a lot will depend on what happens with the polar vortex and the ongoing weakening of the polar vortex (arctic air potential).

~Arctic Air & Winter Storm Risks~ This is a gutsy prediction, and I know I'll get chewed up for days if it doesn't verify. However, the well-advertised Sudden Stratospheric Warming event will lead to a favorable alignment of teleconnections, opening the door for Arctic air to spill into the Midwest and Northeast rather than remaining displaced toward the West and Alaska. The AO (Arctic Oscillation), NAO (North Atlantic Oscillation), and EPO (Eastern Pacific Oscillation) are all expected to trend negative around Thanksgiving. This isn't a typical setup during a strong El Niño, but the rapid weakening of the polar vortex will be the wildcard that changes the equation. I'm confident we'll have legitimate threats for winter storms and Arctic blasts from late November through early December. This is a bold call, but the atmospheric signals are becoming increasingly difficult to ignore.