The below forecast was recently sent out in more complete form to Premium subscribers, who also received our first school delay/closure forecast on Monday. To begin receiving daily email updates before storms on potential impacts, forecast accumulations, expected timing, and school delay/closure forecasts, subscribe here. Otherwise, below we detail the latest forecast update:
Generally, I do not like shifting my forecasts until the confidence is really there that the going one is going to be wrong. However, here I do want to slightly jump ahead of the National Weather Service and overnight weather model guidance in upping forecast snowfall across Fairfield and New Haven Counties. I am forecasting 1-3 inches of snow across Westchester County still, but now expect 2-5 inches across coastal Fairfield County and all of New Haven County. Far inland Fairfield County is still expected to see just 1-3 inches as well as I am not yet convinced that moisture comes in far enough inland for sustained moderate snow. Similarly, I expect eastern New Haven Counties to see the most widespread 4-5 inch regions. Someone over there could see 6+ inches of snow if the storm jogs even a little bit to the west, which is certainly a possibility given the large trends we have been seeing on guidance recently.
One of the big things to note is that as emphasized yesterday, none of these impacts should be felt tomorrow. It will be partly cloudy through most of the day with increasing clouds in the afternoon and evening. Light snow will overspread the region between 4 and 8 PM, though temperatures will still be in the mid 30s. This means that at first snow will struggle to stick on most surfaces. It is not until at least 8 or 9 PM that I see snow sticking along coastal areas, and at that point already up to a tenth of an inch of liquid may have fallen (at least if the RGEM is correct). From there we should see steady snow overnight, but guidance has shifted to show the core of steadiest snow generally being midnight to 4 AM across Westchester County and 1-6 AM across Fairfield and New Haven Counties. This has significantly increased the chances that impacts linger into the morning commute, as snow finally will end between 6 and 10 AM from west to east. Travel should rapidly improve by 9 or 10 AM on Monday as temperatures are relatively quick to rise above freezing and the strong March sun angle should quickly begin to melt the snow, but until then slippery conditions are expected, especially before 7 or 8 AM when temperatures across the entire region will be below freezing.