Watching the Weekend

Quiet – albeit very cold – weather will hang on over the region through the end of the work week and into the start of the weekend before our next shot at wintry weather makes a move into the region.

Model guidance is in fairly good agreement that low pressure will drop southeastward across the Great Lakes and organize east of the Mid-Atlantic on Saturday, before gradually pushing eastward and out to sea south of the region on Sunday and Monday. At the current time, most products available suggest that this low pressure area will produce a swath of light snow across the Northern Mid-Atlantic and parts of New England, with the worst of its weather staying offshore as the storm develops southeast of the region.

That said, a growing number of products depict an evolution to the system that gives pause, despite their relatively meager precipitation forecast charts.

There remains a signal in several products, including the ECMWF, that the low to mid-level circulations (850-500 mb low centers) will become nearly vertically aligned as they dig to the Mid-Atlantic and move eastward into the waters south of New England. This results in a well-aligned, deep NE flow of air off the ocean into the region.

Similarly, “the euro” shows the upper air trough closing off all the way to 300 mb…suggesting a fully vertically stacked system through the atmosphere positioned south of Nantucket by Sunday evening.

If we toss the details and nuances out of the equation (which might be stupid)…and just look at it from a big picture perspective…this is a “good” starting point for a slow-moving / drawn-out snow event in far SE New England.

Of course…as mentioned above…for now most model guidance is fairly limited with the total precipitation over our region, suggesting just a nuisance event overall as the heavier, more organized precipitation resulting from the aforementioned features takes its time to develop and really never materializes until the system is further offshore.

With respect to those outputs, the forecast leans that way right now (light to moderate event). But given the upper air charts, I wouldn’t be surprised to see that shift a bit as we get closer…

Below is a loop of the ECMWF in 24 hour intervals showing the mid to upper level system passing south of the region (click the image if it doesn’t loop automatically).

ECMWF 500 MB Evolution. Note Closed ULL South of New England

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