Biting cold greets us Thursday morning as a cold front moved through overnight with much colder arctic air following in its wake. The front has now pushed offshore and we are left with a bitterly cold day despite an abundance of sunshine. The sun will do nothing to ease the cold as gusty winds bring wind chills down to around 10 degrees through the day. Bitter cold continues overnight and so do the gusty winds bringing wind chill values below zero. These conditions are more reminiscent of a January or February cold snap as temperatures will run some 20 degrees below normal.
On Friday we can expect a more tranquil day as the winds ease up some and temperatures climb about 5 to 7 degrees from the highs on Thursday. It will still be much colder than normal and the sunshine once again will do next to nothing to ease the cold. A secondary arctic front approaches and moves through here during the day. There will be a period of mostly cloudy conditions associated with the front and there is the chance of a passing flurry or snow shower.
Clouds are on the increase Friday night and these will be the forerunners of a storm system that will impact us for a good portion of the weekend. The storm will be located over the South and is forecast to track toward the mid-Atlantic coast where it redevelops and begins to strengthen. During Saturday the coastal low will move south of Long Island and should be near Nantucket Island early Sunday morning.
Meanwhile, high pressure will be centered over southern Quebec and continues to drain very cold air into the area on northerly to northeast winds. Winds are a key to the forecast along the coast because they are expected to turn more easterly later Saturday and Saturday night. With the cold air in place the precipitation begins as all snow on Saturday. Once the winds go around to east and northeast it is a good bet the snow begins to mix with rain and sleet along the coast and may change to mostly rain for a time late Saturday night and or early Sunday. There could be pockets of freezing rain as well, especially away from the coast.
Inland sections will likely remain all snow, mainly west of Route 128/95, although a period of a wintry mix may occur there for a time. Along and west of Route 495 stays all snow through the duration, therefore this area will see the most accumulation.
The storm begins to wind down early Sunday as the system moves into eastern Canada. Conditions begin to improve by Sunday night as the precipitation comes to an end during the afternoon.
Finally, any shift in the storm track is going to change the outlook on the precipitation forecast and who gets any significant snow accumulation. None of the above is etched in stone but rather details the most likely outcome given the computer models analysis. Things can change before the actual event begins to impact us, and often times they do. As always keep in touch with local forecasts from news and weather outlets and please check here for updates as well or on my Twitter feed.
72 Hour Outlook:
Thursday: Bitter cold with gusty winds. Sunshine, with a few afternoon clouds. High temperatures only in the low to mid 20s. West to northwest winds gust to near 25 mph.
Thursday night: A few clouds, windy and very cold. Lows falling into the teens. Gusty west then southwest winds to about 25 mph.
Friday and Friday night: Frigid, highs in the mid to upper 20s. Partly cloudy skies with a chance of a passing flurry or snow shower. Winds becoming west to northwest at 10 to 15 mph, diminishing overnight.
Saturday: Snow develops and cold. Highs only in the low to mid 20s. North to northeast winds 5 to 15 mph.
Saturday night: Snow inland, possibly changing to a wintry mix along the coast. Near steady temperatures may actually rise a few degrees overnight along the coast.