It’s going to be a great day across Western Maine and New Hampshire, and across the rest of the Northeast for that matter. A cold front will be marching through, with showers and thunderstorms along it escorting the oppressive heat and humidity out of the region. Behind the front, Northwesterly winds will begin to usher in cooler and drier air, as Mother Nature becomes slightly less oblivious to the fact that we are now in meteorological fall.
The front is currently located between the Saint Lawrence River, and the Canadian/US border, as of 5:45. Showers along the front are just beginning to move into far NW parts of Maine at this hour, and those showers should be expected to continue moving east through the next few hours as the front drops in.
Farther southeast, we’ll have a few hours to heat the atmosphere up before the front arrives. The farther southeast you go, the longer this window will be. By the time the front arrives along the coast, a considerable amount of instability will have built up, with strong to potentially severe thunderstorms becoming a concern as a result. The most likely area for these storms will be southeast of a line running from Rockland to Lewiston to Keene NH, though not everyone in this area will get a storm. Gusty winds and hail are both potential threats with these storms, in addition to heavy rain and lightning.
Temperatures today will also be determined by the timing of the frontal passage. The mountains, which will see the front arrive this morning, will top out only in the low 70’s. Southern New Hampshire, which will wait until the mid afternoon to see the front, will get all the way up into the low 90’s, with oppressive humidity sticking around as well.
Everyone sees cooler and drier air by sunset tonight, with an absolutely amazing stretch of early fall weather forecast heading into the weekend.