School districts are closing en masse across Southwestern Connecticut, and any district that opts not to close tonight will have to close tomorrow morning. That I am sure of, as short range models continue to confirm that very heavy snow will be moving in tomorrow morning and that all precipitation will be frozen even at the coast through at least 11 AM. The latest HRRR weather model shows snow start at 2 AM and then getting extremely heavy by 6 or 7 AM before mixing with sleet between 7 and 8 AM. Before sleet mixes in there is a chance we could see snowfall rates at or greater than 2 inches per hour, which alone will wreak havoc tomorrow. If sleet is mixing in at that point snowfall amounts will be in the lower ends of the ranges, but I believe it is still possible that parts or most of SWCT get into the upper ranges of the current forecast: 3-7 inches at the coast and 4-8 inches of snow inland.
Along with this, each consecutive run of the RAP and HRRR seems to get slightly colder at the surface, signifying that the freezing rain and ice threat is very likely to last through most of the day tomorrow. The NWS has continued to update forecasts showing more and more snow and for coastal SWCT the latest Winter Storm Warnings calls for up to half an inch of ice. That, along with the snow, could easily bring down power lines and branches, so I am watching the power outage threat very closely here and will be reporting on it tomorrow. This means roads will be extremely icy all day and thus travel should be avoided throughout the day unless absolutely necessary.
Timing is also beginning to become more clear, with confidence growing that the immediate coast of SWCT will mix with sleet at 7 AM and by 8 AM sleet will be mixing with snow along the coastal plane. Sleet will take over for most of the coast and some inland areas (further south there) by 9 AM, and around 10 AM is when I believe freezing rain begins to take over the region. As I was afraid, some cold trends among models show that snowfall amounts of 6-7 inches are possible before freezing rain, again worrying me about trees and power lines. Along with that, extreme intense precipitation will be mainly between 7 and 9 AM, and as I explained in a previous most this could “mix out” the warm layer briefly and result in more snow than a few of the models are currently calling for. After 10 AM freezing rain will take over the coast with a freezing rain/sleet mix likely inland. The immediate coast may still go to rain for a brief period of time after noon before precipitation ends between 1 and 3 PM, but that won’t improve roads very much and will only be right at the coast.
Overall, do not expect road conditions to begin to improve until Thursday morning, really. Tomorrow night roads will be a little bit better, but not by much as temperatures remain below freezing, and there could even be some freezing drizzle in areas. Roads go downhill overnight, and when you wake up tomorrow you’ll either be seeing snow or sleet. The timing is becoming clearer at this point, and I will continue to hone in on it even more. Keep it here for the latest on this storm as I continue to break down the timing and impacts for all of Southwestern Connecticut.