Good afternoon everybody, as we get closer to the event subtle details start to be factored into the forecast.

To set the benchmark of where I was as of this early morning in terms of the lowest accumulation ranges, I had said that some sleet may work into the southern towns of Hartford, Tolland and Windham County, and that 8-12″ of mostly snow with some sleet later in the evening was my expectation.

I also said 8-12″ was possible in western Bennington County, VT due to downsloping, and there is a bit of signal that dry air to the north may cut northern parts of SVT and SWNH down to that 8-12″ as well.

ARGUMENT FOR A BIT MORE SLEET IN SPOTS
This storm, the more I look at it, is really just a so-called “southwest flow event”: a big pile of moisture being shoved northeast into and over a cold Arctic dome, which will result in mostly snow across much of New England except for far southern areas.

The stronger high pressure that will set up to the northeast over Maine along with this exceptionally cold air mass are two big differences compared to previous events in recent years that almost always result in front-end snow thumps followed by icy mix-y messes.

I still think this will be all snow for WMass, CMass, SVT and SWNH, with maybe a little bit of sleet along/south of the Pike toward the 10pm to 1am timeframe Sunday night into very early Monday morning, after the bulk of the snow will be on the ground.

It is the south-of-Pike area, and especially southern halves of the 4 northern CT counties that could see some more sleet mixing in further north up into northern CT that I’m a little concerned about.

Part of this has to do with our secondary low and how it may be a bit weaker than originally forecast when it forms off of the southern NJ and Delaware coastlines.

This can allow milder ocean air flowing west and into the weaker circulation to be drawn a bit more north, and then forced up and over the cold dome into the mid-levels of the atmosphere, creating sleet where that happens.

I still think that the cold dome is going to be so robust and potent that it will be hard to penetrate that warm nose very far north, and I certainly don’t think it will get past the MA/CT state line, with all snow north of there, as of this writing.

But given recent guidance, I’m gonna say that IF sleet does mix in for a time after 8pm or 9pm in northern CT, those areas may end upw tih more like 8-12″ of snow.

If not, we’re all seeing 10-18″ of snow, with some 18″+ pockets where the strongest snow banding sets up.

That 5pm to Midnight timeframe is where snowfall rates could bloom into 1-3″/hour everywhere as the strongest clash of highest amount of moisture slams into the cold air about 2-3 miles aloft and snows out below.

And even if sleet mixes in or changes over, the bottom line is that this is a major winter storm with potent impacts, and that messaging has not changed at all.

Have a great afternoon, and I will update again this early evening, thanks, Dave.