It’s been a week with little sunshine in Connecticut, and while there is a light at the end of the tunnel, we’ve got one more storm system to get through first that will bring rain and close to record warmth to the state on Christmas Eve/Day. After that, however, we begin a slide that will last for several days into a more wintry like regime, possibly culminating with the first widespread accumulating snowfall of the season! Let’s break down the forecast.
Tomorrow and Wednesday will maximize the gloomy pattern that we’ve seen the last several days as a storm system cuts to our west and brings warmth and rain to the state. Rain will be in the cards for most of the day tomorrow right through Christmas morning, and along with that will come close to record highs, with temps making it into the mid to upper 50s tomorrow evening into Christmas morning before temps fall Thursday afternoon as the storm departs. As shown on the departures map below, this is ten to twenty degrees above normal for this time of year! As the storm pulls away, we’ll see temps drop back down to more seasonable, yet still above normal levels as colder air comes in from the west. Here’s images of the forecast MSLP at 7 PM tomorrow night, the warmest expected temps, the total QPF, and the forecast departures from normal all from the 18z GFS model. Model consensus is excellent for this close in event as far as our area goes so just took a blend of all models.
Behind the storm, we finally say goodbye to the clouds, as Thursday afternoon we will see clearing skies and then by Friday, close full sunshine! Friday and Saturday look like incredible days to get outside and enjoy the sunshine, with highs in the upper 40s to lower 50s expected. Don’t expect it to last though, so enjoy it while you can as clouds build again by Sunday in preparation for our next possible system.
Modeling is in relatively good agreement on a system moving north from the gulf Sunday into Monday, but how it tracks and a result it’s sensible impacts for our region are still very much in question. The 18z GFS has an anafrontal signature to it, bringing a broad wave of moderate precipitation across much of the east coast. Given the cold air in place from the EPO ridge pressing down from the north, this would result in an overrunning snow event for the area, similar in nature perhaps to some of the events we saw last winter with the thermal boundary being set up to the south of our area and the axis of the heaviest precipitation riding up along that boundary. The GFS would be an all snow event for our area, with accumulations for all right down to the shoreline. Here’s an image of the MSLP and precipitation type from the GFS at hour 144, that being 1 PM Monday afternoon.
Much colder weather is expected throughout the period, with highs generally in the low to mid 40s Sunday and in the low to mid 30s Monday, although this will vary due to the storm track that ends up verifying. Even colder temps come in behind the storm, with temps perhaps not getting out of the 20s next Tuesday.
We’ll update as needed tomorrow and Christmas day, with a full discussion (along with any needed storm disco) on Friday. Until then, Merry Christmas, Happy Holidays, and thanks for reading Southern Connecticut Weather!