All districts in Southwestern Connecticut have closed except Fairfield. As was expected, due to the severe nature of the storm almost all made the decision the night before, which I believe was the right decision. There is no chance that any school is opening their doors tomorrow with what is coming.
To summarize the going forecast, snow looks to break out across Greenwich/Stamford a little before 2 AM and then overspread the rest of the region through 3 AM. Within an hour of starting snowfall rates will approach or exceed an inch per hour, and they will continue at that rate through 6 or 7 AM. At 6 AM we could see some sleet pellets and graupel mix in at the immediate coast of SWCT, probably Greenwich and Stamford again. By 7 AM areas by I-95 south will likely see some sleet mixing in with the snow, and by 8 AM all coastal areas will likely be dealing with sleet mixing in. Inland areas will only have to wait another hour, if that, to see sleet mix in with their snow. At that time (around 9 AM) freezing rain will begin to take over at the coast, with temperatures around 29-30 degrees. Over the next few hours a snow/sleet/freezing rain mix at the coast will transition to a sleet/freezing rain mix and then just solely freezing rain as temperatures slowly inch towards freezing. Areas may hit freezing or even 33 degrees by 1 or 2 PM, but most of the precipitation has moved on out by then. Further inland, with sleet mixing in at 9 AM, I see the freezing rain beginning to mix in by 10 AM, but sleet could dominate most of the day depending on how much cold air entrenches itself aloft. Light sleet/freezing rain will continue through 2 or 3 PM inland, and precipitation could actually end as a burst of snow. By 4 PM the entire region will be dry and the cleanup will begin.
To highlight some of the biggest threats, first and foremost of course are roads. Once the snow starts, it will be very heavy, and it will have no trouble covering roadways in anywhere from 3-8 inches of a heavy, wet snow with sleet pellets mixed in. Then, you will see a layer of ice on top of that. Thus any time after 2 or 3 AM road conditions will go downhill and I would not advise driving until 4 PM if you absolutely have to, and if not just waiting until Wednesday. There is a chance that road conditions will be so bad that schools will still need to delay on Thursday. Another threat is power outages, which is inherent with any ice storm. Freezing rain freezes on any surface, and it will have no trouble freezing on power lines. Add enough weight, and a few lines could come down, along with branches from trees. Throughout tomorrow morning I’ll be updating on power outages throughout the area, and though I do not expect them to be widespread I would not be at all surprised to see scattered power outages across the entire region.
I remain confident in the final accumulation numbers of 3-7 inches for coastal SWCT and 4-8 inches inland. I think that the main numbers we will see are 5-6 inches for coastal SWCT and 6-7 inches for inland areas, as I think being inland really does only make an inch or so difference as it gives another 30 minutes or hour to 1-2 inch per hour snowfall. Sleet and freezing rain will also compact the snowfall, which will keep amounts from being THAT high and I believe that will keep most amounts solidly within the forecasted ranges.
I want to emphasize one last time that this is probably the largest ice storm I have covered in the past 6 years of weather forecasting for Southwestern Connecticut. It is the first time that I have seen a threat of a third of an inch of ice or more south of the Merritt Parkway, and that is part of the reason why I am taking this threat so seriously. Ice storms are the most dangerous winter weather event in my opinion, even though it may look like just rain. Please stay tuned throughout the day tomorrow as I will let you know when it will be safe to drive, what road conditions are, and where power outages are popping up/where they are most likely. Thank you for bearing with me through this storm and I look forward to keeping you as informed as I can over the coming 24 hours.