We’ve got an impactful storm on the way, with heavy rain, noticeable winds, and high-elevation snow expected for the region starting late tomorrow evening and going into early Saturday. While everyone will see precipitation, we’re expecting accumulating snow to be confined to the interior, and any noticeable impacts from snow to be confined to the northwest hills, where a substantial amount of heavy, wet snow is likely.
Let’s take a look at the setup. Below is a loop of simulated radar from the GFS from Thursday morning through Saturday afternoon, courtesy tropical tidbits.
The story is very different in the NW hills, however, where elevation will allow for colder air to be trapped for longer, which, combined with heavier precipitation rates, should create just enough dynamic cooling for the predominant precipitation type to be heavy wet snow. The range of model solutions ranges from keeping the hills all snow for the duration to mixing with and changing to rain during the peak of the storm when the warm nose is furthest north - we’ll look to hone in on the more exact timing tomorrow once we get some model consensus.
To show that, let’s take a look at soundings (essentially, profiles of the atmosphere) for 1 PM on Friday at ~1500 feet in the NW hills.
As far as total precipitation goes, all models are looking healthy with QPF, with a general 1-2” of liquid expected across the state. We’re certainly not worried about precipitation making it into our area with this storm; it’s the temps that are going to rule the day here for snow accumulations or the lack thereof.
This map is essentially a blend of model solutions that slightly favors the colder solutions, mostly due to the heavy precipitation rates and models often underestimating the amount of cold air available to our north. I think it would take a fairly large shift in guidance to bring totals up substantially, but we’ve certainly seen those shifts before… so never say never. On the other hand, however, a slight shift warmer on models would lead to this primarily being a rain event for all outside of the highest hills in NW CT (2000’+), which, while I don’t think is likely, is still an outcome that’s within the range of plausibility. We’ll hopefully get some more confidence tomorrow and will keep you updated.
Timing & Impacts
If you are hoping for widespread school cancellations, this is not the storm for you. Expect precipitation to move in Thursday night for most of the state. Areas away from the coastline may see a short period of snow at the very beginning of the storm, but that will quickly transition to a wintry mix and then to rain as warmer air works in. Precipitation continues overnight Thursday into Friday morning; if the northwest hills do change over to rain, I’d expect it to happen after sunrise on Friday. Precipitation begins to move out and become more scattered late on Friday, but things likely won’t fully clear out until very early Saturday morning. As colder temps come in on Friday evening, any areas in the hills that turned to rain will turn back to snow, and we may see some brief snow across lower northern areas to wrap things up, though any accumulations will remain minimal. The morning commute is likely to be tricky regardless of whether you are seeing rain or snow, and while widespread cancellations are not expected in Connecticut, they are likely in the NW hill towns, possible in NE hill towns, and far less likely elsewhere. There may be more scattered to widespread delays depending on how quickly things change over to rain.
For most, the main impact will be a wet, windy, raw Friday; it will definitely not be a great day to be outside. In the NW hills, where heavy snow is expected, difficult driving conditions are likely, and the risk of power outages from heavy wet snow is elevated. I don’t think the wind alone will be strong enough to cause major issues, but the snow and wind combined can be a strong one-two punch that will (especially if the snowier side of the forecast verifies) cause power outages, downed trees, etc. Nothing out of the ordinary for this region during the winter, and definitely nothing we haven’t seen before, but taking the usual preparation and precautions (making sure you have some food and water, gas for your generator if you have one, warm clothes, fully charged phones, etc.) will always serve you well.
All in all, expect a cold and wet Friday for most of the state, with a tricky forecast for the NW hills leading to high uncertainty around the risk for heavy wet snow. Luckily, we clear out for the weekend, with mostly sunny skies (especially by Sunday) and crisp temps expected; perfect for holiday shopping, decorating, and, for those of you in the NW hills, shoveling!
We’ll be back tomorrow with a final call. Until then, ask any and all of your questions on our social media pages, share our discussion with your friends and family, and thank you for reading and trusting SCW.