The winter storm that has brought off and on snowfall to the region for the past day and a half will continue today, though today’s round of snow will be the last from this particular system.
Radar imagery shows bands of heavy snow moving onshore in the Midcoast while most of the rest of the area sees lighter snow, or in the case of the mountains, no snow at all. While most of the area will end up with at least some snow by the time the day is done, the heavy Midcoast bands will only make it so far west. The trick to today’s forecast then becomes figuring out where that cutoff point between light snow (2-4″) and heavy snow (6-10″) will set up.
Here’s a look at some of the data I’m using to make the forecast. The storm’s center can be seen about half way between Cape Cod and Nova Scotia with north/northwesterly surface winds across Maine and NH. Bands of strong upward motion (read: heavy snow) will be moving inland ahead of that low, while they recede back towards the east as the low passes by. Figuring out where these pivot points set up is key to figuring out where the western edge of the banding will be.
Based on this information as well as current observational trends and other available high resolution forecast model guidance, it looks like the western edge of the banding will extend from roughly Portland to Farmington Maine. If you’re east of that line, expect periods of heavy snow today. If you’re west of that line, snow will still fall and may accumulate, but it will generally be much lighter.
Here’s a look at some of the high resolution model guidance I mentioned before. The pivoting of the heavy snow bands is readily apparent in this loop, as is the sharp western edge of the precipitation shield. parts of western NH and NW Maine may currently be seeing their last flakes of the storm as the precipitation shield might not extend past the ME/NH border this afternoon.
As far as snow totals go, I don’t have enough time to create an entire map of my own so I’ll leave you with the going NWS forecast which looks pretty good based on my analysis. The heaviest snow will fall along the Midcoast where that banding moves ashore, while western NH may only pick up a dusting. I suspect that the actual gradient between >6″ of snow and <2″ will end up being a bit tighter along the I-95 corridor than is shown in this forecast, but it’s impossible to know precisely through which towns that cutoff will pass until the bands stall and pivot.
Snow will wind down from west to east this afternoon and evening, with some breaks in the overcast developing around sunset in western NH. High temps will range from 25 in the north to around 30 along the coastline.