Computer Model Trends: Potential Nor’easter this weekend

Fred CampagnaDecember 10, 2013

The Tuesday storm was never expected to be a big one, but it is having a hard time living up to its meager expectations. Most areas will likely be close to the 1″ end of our 1-3″ forecast range. The areas we thought had an outside chance of seeing 4″ will probably see 2-2.5″. In some ways these minor systems are the worst for snow lovers because if they under-perform, you’re left with basically nothing. This weekend, however, the potential exists for a storm that could under-perform and still leave significant snow on the ground. The computer models are in agreement that there will be a storm Saturday night into Sunday. There are track differences, and resulting precipitation-type issues. The potential exists for anywhere from a blockbuster (12″) storm to a wintry mix that changes to rain. Let’s get a look at the computer models…

GFS

12Z GFS - Saturday afternoon - snow developing ahead of the system. — 12Z GFS – Saturday afternoon – snow developing ahead of the system.

12Z GFS - Saturday night - A wintry mix in SNE. Snow inland, mix in I-95 corridor, rain at the coast — 12Z GFS – Saturday night – A wintry mix in SNE. Snow inland, mix in I-95 corridor, rain at the coast

12Z GFS - Sunday - lingering snow showers and flurries — 12Z GFS – Sunday – lingering snow showers and flurries – very cold!

12Z GFS Snow Forecast - Subtract about 2" for the snow that the model projected for Tuesday — 12Z GFS Snow Forecast – Subtract about 2″ for the snow that the model projected for Tuesday

12Z GFS Snow DEPTH - notice the sharp cutoff as the sleet/rain cuts into the accumulation in the I-95 corridor — 12Z GFS Snow DEPTH – notice the sharp cutoff as the sleet/rain cuts into the accumulation in the I-95 corridor

CANADIAN

12Z CMC - there is still enough cold air at the onset for snow to a wintry mix, but the track of the storm is not favorable for all snow. — 12Z CMC – there is still enough cold air at the onset for snow to a wintry mix, but the track of the storm is not favorable for all snow.

12Z CMC - Storm track over SNE is not favorable for snow in I-95 corridor to coast at the height of the storm — 12Z CMC – Storm track over SNE is not favorable for snow in I-95 corridor to coast at the height of the storm

12Z CMC snow forecast - as expected with the inland track the snow totals are pushed north and west of I-95 corridor — 12Z CMC snow forecast – as expected with the inland track the snow totals are pushed north and west of I-95 corridor

ECMWF

ECMWF - 24 hour snowfall totals are impressive - to say the least. — ECMWF – 24 hour snowfall totals are impressive – to say the least.

12Z ECMWF - While we're dreaming, here's the 10-day snow total after another system in the middle of next week. Up to 30" in SNE, and a half-season's worth in BOS and PVD. Probably not going to happen. — 12Z ECMWF – While we’re dreaming, here’s the 10-day snow total after another system in the middle of next week. Up to 30″ in SNE, and a half-season’s worth in BOS and PVD. Probably not going to happen.

JAPANESE (JMA)

12Z JMA model takes a track just south of SNE. Not as much precipitation, but still a moderate snowstorm.

GFS ENSEMBLES

12Z GFS Ensemble - Wah, wah. Most of these members bring enough mld air into SNE to lead to a wintry mix or rain in the I-95 corridor, and rain near the coast. — 12Z GFS Ensemble – Wah, wah. Most of these members bring enough mld air into SNE to lead to a wintry mix or rain in the I-95 corridor, and rain near the coast.

THE BOTTOM LINE

It’s early in the game, but the signal is there for a potentially substantial winter storm this weekend. Even though it’s going to be bitter cold for the rest of the workweek, the high pressure system that will bring the cold weather will not stay locked in to the north of New England. Therefore, the storm track is critical, and the early odds favor it coming close enough for some mix/rain from the coast to I-95. Since it is so early, there is time for the models to change considerably. I’m sure there will be some back and forth with the storm’s track based on how the models are handling the cold weather heading for the Northeast which has a fresh snowpack on the ground. Is there hope for a big snowstorm? Yes. We’ll see which way the models trend on Wednesday.

GFS

CANADIAN

ECMWF

JAPANESE (JMA)

GFS ENSEMBLES

THE BOTTOM LINE

Fred Campagna

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