Summer Starts...
It may be unofficial but it will feel official as we kick off the Memorial Day weekend with Summer heat and highs of 85-90! Don't be discouraged when you get up in the morning and it's a little murky with clouds and fog, it will burn off fast and we'll have blazing sunshine most of the day. I suppose there is a slight storm chance in the afternoon but with heating aloft the atmosphere will remain primarily capped inhibiting development. A front will actually slide through early in the morning and winds behind it will be out of the west...a less humid airmass will invade the region scouring out the mugginess.
That same front will return as a warmfront on Sunday and stall right over us. In my opinion, it will take some time to saturate the air and therefore most showers and thunderstorms will hold off until later in the day and evening. This means that most of the day will be dry with a sun and cloud mix. Temps inland should be close to 80 and at the coast in the 70s...not too bad though.
The front will become very active Sunday night and early Monday morning as a cluster of thunderstorms from the Great Lakes follows the path of the front into New England. Most of the time, thunderstorms fade during the night but the large contrast in temperature across the frontal plane will keep these going and rumbles may awaken you at some point.
Most of that action should be gone first thing but timing these clusters is tough and may linger into the mid-morning on Memorial Day. After that, clouds will break for some sunny breaks (except on the Cape and over some coastal towns with onshore winds) which may lead to another pop-up shower or storm later in the day. Highs with the onshore component should stay in the 70s (except 60s Cape & Islands).
As you can see, not one day is going to be a washout and most of the time will be rain-free with temperatures well above the normal of 70. Enjoy the long holiday weekend.