A cold front moving through the state as of this writing will usher in a cooler (not a particularly cold air mass but cold enough) airmass for overnight Sunday and Monday morning. A weak area of high pressure well to our north will sort of help with reinforcing some cooler air into the state through tomorrow morning. Forecast models all show some shortwave energy moving through a rather progressive zonal flow aloft. This shortwave energy will help aid in the development of a surface area of low pressure which will pass to the south of Long Island. This track will help keep cooler air in place across Connecticut:
While this system will be moving rather quickly, forecast models all agree there will be some very strong upward vertical motion with this system and this could lead to a rather narrow band of moderate to heavy snowfall. The question is where this band sets-up. There is the possibility this could end up just south of Connecticut but there are some indications this could happen across southern Connecticut. This will ultimately be tied to the exact track of the storm. Both the NAM and GFS indicate a period of rather solid 800mb-600mb frontogenesis traversing the entire state tomorrow morning along with a small window of some excellent upward vertical motion intersecting the dendritic snow growth zone. This will yield a brief period of moderate to heavy snow tomorrow morning:
With surface temperatures in the upper 20's and temperatures throughout the lower and mid-troposphere well below-freezing, this combined with the excellent upward vertical motion and high relative humidity within the snowgrowth zone should yield higher than average snowfall ratios. Bufkit soundings indicate snowfall rations perhaps as high as 13:1. This indicates we will be dealing with rather fluffy snow and the kind of snow that can accumulate easily:
So what can we expect?
While temperatures will certainly be cold enough, it may be a bit difficult for snow to initially stick to paved surfaces. This has nothing to do with higher/stronger April Sun angle (the snow is falling during the early morning hours!) but with the fact that the ground will be relatively warm. In order for the snow to stick to paved surfaces it will have to come down moderate to heavy for a good duration. Otherwise we're mainly talking about accumulations on grassy/colder surfaces (such as cars).
- Snow should begin breaking out between 4:00 AM and 6:00 AM Monday morning.
- Expect light to moderate (and at times even heavy snow) through the morning commute. This will lead to delays and slick travel so be sure to give yourself extra time in the morning.
- With the warm ground and likely pre-treatment of roadways and paved surfaces, snow will have trouble sticking, however, in any areas which receive a prolonged period of moderate to heavy snowfall snow will begin to stick to paved surfaces.
- The window for the moderate to heavy snowfall will between 8:00 AM and 11:00 AM.
- Snow quickly begins to lighten up and taper off after 11:00 AM.
- With temperatures warming into the 40's during the afternoon whatever accumulates will quickly melt.
- If we do indeed see a band of heavier snow set-up, this could yield a zone of snowfall totals upwards of 2-4''.
- Below is what I'm thinking:
