Major to Significant Winter Storm To Impact southern New England Thursday into early Friday

Over the past few days confidence has vastly increased that a storm system developing across the southeastern United States will work up and track close enough to the coast to impact southern New England.  With several sets of computer forecast guidance suggesting a rather strong system, these impacts will be rather significant as portions of the region will see major (8-12'') to significant (12''+) snowfall accumulations.  Given the expected track of the system, we will also have to contend with plain rain, sleet, and perhaps some freezing rain.  This system will also be accompanied by some strong winds as well.

While confidence is extremely high of a storm track close enough to the coast to impact the entire region, there is still a great deal of uncertainty with regards to the exact track of this storm system.  This is ultimately going to be absolutely huge when it comes to determining who remains all snow, who mixes or changes to rain, and where the axis of the highest snowfall totals will occur.  Unlike some of the past storms we have had this winter, we don't have a high pressure system to our north to keep colder air locked in place across the region and with the models strengthening this system very rapidly off the Carolina coast, this will allow for warmer air to try and work into portions of southern New England.  A track difference west/east of as little as 30-50 miles will be the difference between something like 3-6'' of snow and potentially as much as 12''!

What we also have to watch is the track of the 700mb low.  This is extremely important for two different reasons.  1) The highest snowfall totals along with the heaviest banding of snowfall occurs just to the northwest of the low pressure track.  This is where lift is typically the strongest along with very strong forcing.  2) Areas virtually in the direct path of the low track and just south and east typically end up being in the dry slot.  This is where drier air from aloft descends downward or when drier air gets wrapped into the system.  The drier air eats at the precipitation and the moisture and areas within this zone see very little to no precipitation and something like this can vastly affect snowfall totals.

Given how close to the coast this system will track and with warmer air that will be working into portions of the region, this will create a tight baroclinic zone (greater temperature difference over a small area).  This also works to vastly increase lift and forcing, just to the west of this zone and where this zone sets up is where the heaviest snows and higher totals will occur.

With a potent storm system which will continue to strengthen as it works up the coast this will also increase the pressure gradient across the region and a period of strong winds will be introduced.  Winds could gust as high as 35-45 mph region wide, and especially across the coast.  This will lead to isolated to scattered power outages along with perhaps blizzard conditions in some spots.

The first impacts from the storm will begin very early Thursday morning, right around dawn or just a bit after with everyone starting off as snow.  The timing of the storm will likely lead to a great deal of school cancellations throughout the region.  For those heading to work the travel commute will deteriorate very quickly and expect numerous delays.

The height of the storm will occur between about 10 AM and 10 PM.  During this time snowfall rates may approach 3''/HR in the areas where the heaviest banding occurs.  Winds will also increase as well as the afternoon goes on with gusts approaching 35-45 mph, especially towards the coast.  For areas south and east snow the snow will eventually transition over to sleet and then rain thus the lesser snow totals.

Given everything mentioned above, this is what I'm currently thinking as far as snowfall totals go: