Good morning, friends! Monday started off wonderfully, albeit cold, throughout the majority of the Northeast states. Plenty of sunshine is expected to persist throughout the remainder of the day today as well, as high pressure remains in control. The cold air has remained stout, and will continue to do so for a few more days, with temperatures running below seasonal averages throughout the Northeast states.
There is growing confidence that a possible snowstorm will affect the Northeast U.S. during the middle of next week, as the ingredients needed for one to occur are beginning to consistently show up on the models. It seems this winter has been relentless with the constant cold and frequent snowfalls. This type of pattern just does not want to let go — not yet, at least.
GFS Ensembles showing 500mb height anomalies well below normal across the Northeast US by next week in response to blocking developing in Greenland and Northern Canada.
It may be a bit premature to say that Spring will be off to a cold start. Medium and long range forecast guidance, however, would say that is a fair forecast. Forecast guidance has been pointing to the development of a very strong high latitude blocking episode within the next week, which could include a NAO and EPO ridge. The combination of the two could force a piece of the Polar Vortex (and very cold arctic air) into South-Central and South-East Canada, meaning our chances of below normal temperatures would increase … especially the farther north you go.
It seems, at least to the meteorologist, that there is a bit of an underlying passiveness towards March snowfall events in the New York City Area. I guess this comes somewhat naturally due to the past several years, which have offered very little hope for March snowfall (running well below normal in our area over the last 5-10 March’s). In fact, last year around this time much of the area saw temperatures soar into the 70’s for highs. Lets face it, March has been a nonexistent winter month in our area with the exception of a storm in 2009 which produced significant snowfall in parts of the area.
GFS Ensemble forecast Arctic Oscillation readings.Notice the rapid dropoff over the next week.
With all of that said, most of you are probably asking yourself: Why would it suddenly get cold and potentially snow this March? What makes it so much easier this time? The answer is that it won’t be that much easier. It still will be more difficult to get snow this time of year given the longer days, stronger sun, and warmer ground. But it is important to remember that forecast guidance has been strongly pointing towards the potential for a significant blocking episode — not just a run of the mill Greenland block or positive height anomaly. We can begin to see this response just glancing at the Arctic Oscillation forecasts, with remarkable ensemble agreement on the AO readings falling off the proverbial cliff. Almost every ensemble member brings the Arctic Oscillation below -4 and some of them to -5 — this is not your basic – AO development. It’s worth noting, too, how much lower these readings are compared to even the lowest readings of the past few months. A word of caution though, we should carefully watch the AO over the next several days as it has outrun the 7 day ensembles forecast in a positive direction recently (bottom chart).