Thursday Snowstorm Looking More Likely

Computer forecast models are beginning to become into stronger agreement over a quick hitting but rather significant winter storm late Wednesday night lasting through the first part of Thursday.  Despite how close we are timewise, there continues to be some uncertainties with regards to the exact track and strength so that suggests this will be a rather delicate forecast with a high room for bust potential.

By early Thursday morning a shortwave trough and associated shortwave energy really begins to amplify (strengthen) rather quickly.  This is due to the very impressive 120+ knot 500mb mid-level jet streak which begins to round the base of the amplifying trough.  The response from here is for rapid cyclogenesis (development and strengthening of a surface low pressure system) to occur:

 
There are some differences between the computer forecast models, however, on exactly how this evolution evolves, the strength of these features, and timing and hopefully this will be resolved as newer data rolls out later this afternoon, however, the consensus is point towards at least some type of impact.

One other indicator for the potential for at least a heavy swath of snowfall is a very impressive thermal gradient which will exist between southern Canada and just south of New England.  Illustrating this looking at 850mb temperatures (~5,000ft) temperatures are forecasted to be around -20C in southeast Canada and near +8C south of New England.  This yields a rather impressive gradient which is something that can really enhance forcing and vertical lift:

Both the NAM and GFS computer forecast models are also showing a several hour period of excellent snowgrowth coupled with vigorous lift within the snowgrowth zone.  Taking a look at a bufkit profile from this morning's run of the NAM forecast model over Waterbury, CT we see a several hour period where the snowgrowth zone (purple and yellow contours) is between 12,000-18,000ft (prime location) with the -15C temperature contour running through this zone (helps to maximize snowgrowth) and excellent upward vertical lift (red contours with negative values) within this zone (as much as 20-30 units of omega!!!).  All this indicates that there will be a several hour period of moderate to extremely heavy snowfall where snowfall rates could approach 3'' per hour during the peak:

A few other things to watch are developments of closed off low pressure center at 925mb, 850mb, and perhapd 700mb.  This would indicate a very intense system and the track of the lows would have to be watched too.  All models developed at least a closed low up to 850mb but some tracks vary.  In order to maximize snowfall rates and intensities you want to be on the northwestern side of these tracks:

All in all guidance is coming together for a potential quick hitting but potent snow event.  This could potentially be the biggest event of the season for many.  I will have another update this afternoon including a snowfall map.