Significant Winter Storm Update

 I have been very impressed with the potential for heavy banding to materialize across Connecticut all along and we we get closer to the event I've become way more impressed. There are signals for a hellacious band of extremely heavy snow to impact southwestern Connecticut and northeastern Connecticut. It is a bit more challenging in the Connecticut River Valley (Windsor Locks, Hartford, this corridor) as subsidence could lead to totals on the lower end of the range. 

Forecast models are indicating extreme frontogenesis traversing the state by Monday afternoon into the early evening. Now, usually when forecasting higher end totals (getting above 15-18'') you would like to see the signal for banding stall and pivot. While this isn't necessarily happening here, very high snowfall ratios (perhaps 15:1 - 18:1) combined with hefty QPF totals tell me that it will dump 2-3'' per hour for several hours:

Below is looking at White Plains, NY. While not Connecticut, this is just over the border and not far from Greenwich. The two isotherms (-12C and -18C) highlight the dendritic snow growth layer (DGZ). This is the layer in which snow growth is maximized. At this location, this is showing the most extreme lift just below the DGZ, however, in southwest Connecticut, we may maximize this lift into the layer. This is a very strong signal for extremely heavy snow:

Let's break all this down:

• Snow begins likely during the pre-dawn hours Monday morning (especially across southern Connecticut) with snow spreading north through the early morning. 
• Snow rates quickly increase by late morning and early afternoon. 
• The absolute heaviest of the snow falls between 12:00 PM - 8:00 PM EST. This is when snowfall rates could approach 2-3 inches per hour (potentially even 4).
• Some thunder is possible
• Winds increase out of the northeast to 15-25 mph (25-35 along the shoreline) with gusts 40-50 mph (upwards of 55 along the shoreline). This will bring about blizzard conditions with extremely poor visibility, drifting snow, and isolated power outages.
• Afternoon and evening commute may be near impossible and extremely dangerous due to rapidly accumulating snow, very poor visibility, and high winds. 
• Light snow continues well into Tuesday morning.
• There will likely be some sleet and freezing rain involved along the shoreline and even extending well inland, especially during the overnight as precipitation intensities wind down and the storm takes a wonky track. 

Below, is my update: