New England’s weather pattern will slowly be evolving over the next few days. For much of this past week, New England’s basic weather setup has involved an expansive upper level low hanging around eastern Canada with high pressure at the surface. This has led to unsettled weather at times, but also long bouts of very nice weather. Through this weekend, this rather stagnant setup will be changing.
There are four main weather features around the northeast, all of which are slow-moving, so the evolution of the pattern will be very gradual through the middle of next week. These four features are an expansive upper-level low over the Canadian Maritimes (which has been responsible for rotating weak disturbances into New England this week), surface high pressure (responsible for the longer bouts of pleasant weather), a frontal system to the west and Hurricane Ernesto well offshore.
For Saturday, this setup will lead to most of New England remaining dry, albeit with a lot of cloud cover. The exception will be far western New England, where isolated showers could pop up. Scattered showers will continue to pinwheel around the frontal system to the west, but the log jam of features to the east will prevent much progress into New England. In addition, the high pressure remains generally in control, keeping drier air over much of New England.