Today will feature the slow approach of a strong late-season snowstorm, though you’d hardly know it looking outside this morning. Skies are crystal clear over most of Maine while clouds are only starting to advance into New Hampshire. Everything about this storm’s evolution will be slow thanks to strong “blocking” high pressure over eastern Canada.
The storm’s approach today will slowly push clouds from NH into ME and rain from VT into NH. With southeasterly winds ahead of the primary low over the Great Lakes, I’m not expecting any snow today unless you head above 3500ft in the Whites. Temps today will range from the mid 40s in SW NH under the thickest clouds and along the Midcoast with the strongest onshore flow to near 60 northeast of Augusta where sunshine will hold out the longest this morning.
Maine should remain mostly dry until the next phase of the storm begins tonight. That next phase involves, you guessed it, the development of a secondary area of low pressure over Cape Cod. As that storm rapidly intensifies, winds will back around to the northeast, temps will quickly fall, and rain will start changing over to snow even outside the higher summits. By tomorrow morning, snow will be falling across most of the area with rain confined to the immediate coast.
How much snow is expected? That’s always a tough question, but especially in the “shoulder season” where tiny changes in temperatures or precipitation rates can produce vastly different snow totals. Right now, it looks like 6-12″ is a good bet in the mountains and foothills, with elevation playing a big role in determining who ends up where in that range. As you slide out of the foothills into the coastal plain, 2-6″ is a better bet again with elevation playing a big part. Points east of I-95/I-295/Rt 1 will be lucky to pick up a slushy 1-2″ as the east-northeast wind is just onshore enough to keep precipitation more of a rain/snow mix, at least during the day.
This snow will be as heavy and wet as snow can come, which means that you only need about 3-5″ to start causing significant power outage concerns. This is especially true when east/northeast winds start gusting into the 25-35 mph range which is expected on Friday afternoon/evening. Unless you’re right along the coast, take some time today to prepare for power outages that could last a little while. Around this time last year, we had a similar storm drop 6-12″ of snow across much of the area and over 200,000 people lost power. Unfortunately, we may be headed for similar numbers with this one if current forecast expectations pan out. Thankfully, temps will jump back into the 50s this weekend so restoration efforts should be unencumbered by Mother Nature.
I’ll have more details on this storm either tonight or in tomorrow morning’s update.