Mixed signals emerging involving a potential weekend snowstorm. Unfortunately, at this time, most signals point toward a “no go.” This is a huge wasted opportunity given the massive -NAO block over Greenland and a -AO in the northern latitudes.
Here’s what we have at 12z:
12z GGEM – Glancing blow with some (late) southern stream phasing with the polar vortex. Strong closed low over Canadian Maritimes keeps confluence to our north and keeps flow flat enough so this thing doesn’t amplify in time. This solution is further offshore than the 00z run.
12z GFS – Close to the 12z GGEM but a touch further offshore. Same problems. Confluence over the Maritimes keeping the flow too flat which in turns leads to a late phase. Glancing blow for southeast Mass. This solution, however, is significantly closer to the coast than the 00z GFS run.
12z Euro – A bit more impressive with the 2nd shortwave but the flow remains flat and the storm misses after a decent hit in the Mid Atlantic. No major change here as of yet.
12z UKMet – miss to the east
Why is there even any threat of a system based on the above?? Good question! For one some of the GFS ensemble members remain quite wrapped up and in fact the ensemble mean is further west than the op. Given what a mess this synoptic pattern is I’m not surprised and I think this storm may have some surprises in it. This is one of the situations where an ensemble based forecast approach can have benefits. Therefore I think the odds of something happening are a bit greater than what the 12z op runs show.
We’ll have to watch for a faster phase/further west which can only happen if the closed low to our north scoots west and weakens in time to let the flow amplify. Otherwise it’s a disaster of an amazing -NAO pattern.
Odds for a significant snowstorm here are probably less than 20 percent. The Mid Atlantic, however, could see something nice especially in coastal areas!