1st Call Snowfall Map for Saturday, January 26th, 2016 Storm

Throughout the course of the week major headlines have been made for a potentially major winter storm to impact the mid-Atlantic and Northeast states this weekend.  Since the end of last weekend (nearly a week ahead of the projected event!) computer forecast guidance has been very consistent in showing a storm impacting these regions.  The only questions were where does the biggest impacts occur and where what kind of snowfall amounts we would be looking at.  Over the past 24-hours the situation has started to become much more clear and it is looking like the biggest impacts and highest snowfall accumulations will be from NJ on south into the mid-Atlantic where the highest snowfall totals could approach 18-24''!  For us here in CT we will not see nearly as much snow or much in the way of serious impacts from this system.  

Below are graphics from the overnight run of the GFS forecast model looking at late overnight Saturday (1:00 AM EST) focusing on the 500mb, 700mb, and 850mb levels.  Highlighted are the centers of low pressures at these levels.  Those smaller closed contours within the highlighted area indicate the system is "closed off" which indicates the system has reached peaked intensity.  Given how far south of CT, this is occurring this indicates that moisture inflow from the Atlantic will be shut off from entering the system and will result in a decrease in the precipitation the storm has to offer.  These pressure centers tracking further south also indicate the strongest lifting will be well south and west of this area:

  

The below graphic is a GFS bufkit profile for Waterbury, CT also from the overnight run of the GFS.  Here we are looking at a profile of the atmosphere.  There are several highlighted areas.  

1) The circled area is the area of best snow growth.  You want this zone to be located inbetween the -12C and -18C isotherms as this is the desired range for best snowgrowth.  While I did not overlay the temperature contours (it starts to get a little messy with lots of overlays) the snowgrowth zone is located in this range which is a good thing!

2) The red contours indicate upward vertical motion (rising air) and the blue contours indicate downward vertical motion (sinking air).  What you want to see is lots of upward vertical motion within the best snowgrowth zone and you DO NOT want to see any blue contours within this zone as that would lead to sinking air and a decrease in precipitation.  Notice how within the snowgrowth zone we aren't seeing much in the way of upward vertical motion, this indicate we likely will not see much in the way of heavy snowfall rates.  

3) Also plotted are relative humidity values, the higher the relative humidity, the more saturated the air is said to be.  In this case we would like to see higher relative humidity vales than what are depicted and would also like to see values >90% (which is what is only plotted) be within the best snowgrowth zone too.  Looking at the relative humidity values there could be some dry layers in the atmosphere which could allow for some snow to evaporate before reaching the ground:

With the above said, below is what I am currently thinking as far as snowfall totals are concerned across the state:

Outside of snow we will also see some fairly strong wind gusts with this system as well with winds gusting at times to 40-50 mph.  Despite not much in the way of snowfall goes as far as totals this could yield to blizzard-like conditions at times, especially when snow is falling at a heavier rate.  We could also see some isolated power outages as well.