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Another winter weather event possible Tuesday

In what now seems to be a never-ending parade of winter weather, forecast models have come into agreement on the potential for another winter weather event on this coming Tuesday. Here’s the change-up with this one: The wintry weather seems more likely to stay south of New York as opposed to north.

A mid level shortwave trough will eject northeastward from the South-Central United States early this week, and in doing so will spawn the development of a surface low over the Mississippi Valley. This surface low will shift northeast with time, toward the Mid Atlantic states on Monday and Tuesday. While the mid level energy de-amplifies a bit, the storm system will move toward the coast.

Precipitation is expected to spread north through the Mid Atlantic and eventually into New Jersey on Tuesday. But with the de-amplifying energy aloft, the question at hand becomes the northern extent of precipitation. Forecast models have been waffling back and forth between moving precipitation farther north, and shifting it farther south.

Again, this obviously will have major impacts on the forecast in our area. A farther north track would mean a more widespread winter weather event, while a farther south track with precipitation would mean a lighter event — and moderate totals confined to the Mid Atlantic. Currently, confidence is highest that the best snow will remain south of New York City, over the Mid Atlantic and parts of New Jersey.

GFS model showing snow on Tuesday, with the heaviest and steadiest snow to the south of NYC.

Why, you ask? Simple: Pattern progression. We’re in a fast, active mid and upper level atmospheric pattern and this storm isn’t doing much to slow things down. It’s a generally weak and de-amplified system aloft, with no phasing and no huge amounts of energy. Forecast models have trended south and east with almost every storm this winter inside 60 hours — and they’ve already begun doing the same with this one.

The mid and upper level jet structure and the progression of the atmospheric pattern lends confidence to our ideas that the storm will remain progressive and not track far enough north to bring a major winter weather event to our area. Still, moderate snow amounts are possible across parts of the Mid Atlantic and into New Jersey. We currently anticipate a stripe of 3-6″ of snow will set up in those areas — but mesoscale models will help us pin down exactly where that location will be.

Farther north, snow amounts of 1-3″ can be expected in Northern NJ, Southwest CT, New York City — with 2-4″ possible on Long Island. Still, this is our lowest confidence area : Only a slight change in the forecast track could bring amounts closer to 3-6″ as the event unfolds on Tuesday.

Stay tuned over the next 24 hours as new high resolution model data will help us get a much better idea as to what is coming our way.

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