Another day of unsettled weather is on the agenda for today, this time with the added excitement of Arctic air and a powerful Norlun trough.
Temps this morning are on the cooler side of normal, though well within the range of what’s typical for New England in January. Readings are right around zero in the mountains and near 10 along the coast. These cold temps are the result of Arctic air that poured into the region overnight on the back of gusty NW winds which will continue today. That means that wind chills will remain near or below zero for most of the area for most of the day, so bundle up if you’re headed outside!
Farther to our east, maritime air is pushing west from the Canadian Maritimes. The boundary between this cool/moist maritime airmass and the cold/dry Arctic airmass most of the region is experiencing this morning is known as a Norlun trough. These features are known for producing narrow bands of extremely heavy snow. Sure enough, radar imagery this morning shows a nice band of snow extending from Penobscot Bay south into the Gulf of Maine. The big forecast question today is how far inland can this band push as it pivots southwest and eventually south towards Cape Cod.
At the moment, it looks like most of the coastal plain will see at least some snow from this trough today. Parts of the midcoast, especially closer to Penobscot Bay, could pick up a few inches of fluff. Coastal areas farther SW could see up to 1-2″ of snow as the band rotates through this afternoon. Dustings will be more common as you move towards the foothills, while any snow up in the mountains will be driven more by upsloping than this trough feature.
Even those only expecting a dusting to an inch today should use extra caution on the roads as this morning’s cold airmass means that snow will stick immediately and gusty NW winds will easily blow the fluffy snow around. Snow will pivot south of the area by late this afternoon. The heaviest snow will likely fall mid-late morning along the Midcoast and early this afternoon in the Portland area.
Behind this trough, we’ll actually tap into that relatively milder maritime air so high temps will make it all the way up into the 20s along the coast and parts of the foothills closer to Farmington/Augusta. Points farther SW will be a bit cooler in the upper 10s while the mountains stay locked in the high single digits to low 10s.