We’ve updated our forecast map slightly to reflect a slightly larger range of possible totals for snow for tonight into tomorrow due to some of the guidance at 12z and 18z today trending towards a further west and stronger solution, bringing more liquid to the state and therefore more snow. This west trend, however, has brought into question temperatures for the event, and as a result, small changes in the temperature at the surface and upper levels will have a major impact on what we see in so far as sensible weather. As a result, this is a low confidence forecast.
On the shoreline, we’re expecting rain to start this evening, mixing with and then changing to snow overnight. We’re expecting anywhere from a coating to an inch of snowfall, mainly on grass and other cold surfaces. If the system was to trend colder, we might see a little more than an inch, but for now, we’re not confident enough in that to go any higher.
For most of the interior, we’re expecting a coating to two inches of snowfall. The reasoning for the bigger range is that precipitation is expected to flash over to snow right when the rates are heaviest, and as a result, even a change of an hour or two in changeover time from the consensus will result in a significant change in the sensible weather, whether that be in the form of higher or lower totals. In general though, the further north and higher you are, the more likely it is that you’ll be towards the 2” end of the range.
For the NE and NW hills, we’re forecasting one to two inches of snow. This is the trickiest part of the forecast, as some models try to set up a deformation band over NW CT, and some over NE CT, while some have none at all. As a result, wherever that deformation band sets up, if it does, will have higher rates, and given that these locations are north and elevated, that would result in at least the high end of the range and possibly up to 3” or so. Not confident enough in that scenario occurring to raise the high end of the range, but considering elevation and temperature along with reasonably significant amounts of QPF, I’m confident in these areas seeing at least an inch of snow.
Here's the map.
In terms of impacts, expect messy roads tonight and tomorrow morning, especially on secondary and tertiary roads, which have not been treated. Conditions will likely be tricky for at least part of the state during the morning rush, and that could even include I95 if the system is on the cooler side. Some delayed openings are possible from the schools, although I don’t expect any snow days as a result of this system. If you’re heading out tonight or tomorrow morning, take it slow and be safe!
We’ll be watching the models, radar and obs all night long, and will update as needed with any changes, but until then, enjoy the snow and thanks for reading Southern Connecticut Weather!