Quick Storm Analysis

I will say I am pleasantly shocked that some snow has already began to fall across parts of CT and started as early as 2-3 PM.  Granted it was very light snow and tiny flakes but still indeed snow.  My main concern was the dryness of the atmosphere and how long it would take for the atmosphere to saturate .  Taking a look at a forecast sounding from the 4:00 PM EST (21z) run of the RAP computer forecast model timed for about 7:00 PM EST the atmosphere certainly becomes quite close to saturated from about 525mb down to the surface (note how the dewpoint (green) line and temperature (red) line are pretty much touching:

The snow that has been falling is related to the system, however, it's not necessarily from the system.  I say this because the focus of lift is completely different.  The snow which has fallen thus far has been the product of at least these two factors; 1) warm-air advection in the lowest levels of the atmosphere and 2) enhanced low-level lift from the nose of the 850mb jet:

Thanks to a very cold airmass in place and quite the cold ground, despite the fact the snow is falling very lightly and the flake size is very tiny (this is more like snow grains!) it is sticking.  In fact, some areas have a coating on the ground, including at Westside Campus at Western Connecticut State in Danbury, CT!  If there was more in the way of mid-level lift to lift parcels into the mid-levels of the atmosphere we would be seeing beautiful dendrites and big fluffy snow flakes.  Looking at the same 21z RAP we see very good dendritic snowgrowth right in the favorable area for snowgrowth (between -12C and -18C) with the -15C isotherm running right through this zone.  When you have these ingredients in place you get your perfect snowflakes which are big in size and these are the ones that accumulate quickly.  The only issue is there is no lift in this zone.  For upward vertical motion we want to see red contours but we do not have those present into this zone thus we aren't lifting air parcels or moisture into this zone so the end result is these little tiny snowflakes:

Currently the area of surface low pressure which is the main aspect of the system is still well off to our  west over the Ohio Valley region.  This low pressure will continue to strengthen but slide off to our north and west and with this track we will continue to see warm-air advection occur and warmer temperatures filter in.  Until then we will continue to see some snow and later on this evening/early overnight the flake size should increase as stronger mid-level lift slides in.  However, the timeframe for this bigger flake size and heavier snow rates will be brief (especially in CT) and snow totals will be down here.  I see no reason to make any changes to my map fro Friday night: