Elliott shared the following over the weekend:
"For anyone thinking that Greenland blocking (a -NAO) guarantees snow and cold for the mid-Atlantic States, you need only look back to last #December. The NAO was - for the last two weeks of the month, but temps were still 8°F above normal for the month at @millersvilleu.."
And he went on to say this:
"By the end of next week and beyond, uncertainty in the forecast increases significantly. A large-scale pattern change featuring the development of pronounced, high-latitude blocking will get underway this weekend and continue to mature next week. The North Atlantic Oscillation (NAO) is projected to turn strongly negative as a large, Jet Stream ridge develops over Greenland. How the strength, location, and orientation of this "Greenland Block" evolves will play a crucial role in determining how our weather plays out during the middle of the month. These blocking patterns traditionally support a greater likelihood of accumulating snow in the I-81 and I-95 corridors, but they don't guarantee it. In addition, numerical computer models are notoriously bad at handling Greenland blocking and exhibit drastic, run-to-run differences. If you're a snow- or winter-weather lover, then you want the blocking high pressure system to ultimately shift to the south/west of Greenland and become oriented north-to-south. At this distance, only a fool would pretend to know IF and WHEN this might happen. There's plenty of "hype" on social media with respect to winter weather "potential" in the mid-Atlantic during the middle of the month, but just remember that you can't shovel potential!"