After high pressure builds into New England today, a trough will cross the region starting tonight. This system will bring a period of beneficial rain and usher in a cooler, more October-like air mass into the region. An upper-level system will pass well to the north of New England, dragging its fronts across the region. This may spawn a surface low near New England, which would help create more widespread showers. These showers will move west east starting Sunday night for western New England and moving eastward through the day Monday.
Showers associated with the cold front will enter into western New England late tonight, likely around midnight. Showers will continue to move eastward at a decent clip through the night. By sunrise, the main batch of rain will have likely moved out of Vermont and into New Hampshire, Maine, eastern Massachusetts and Rhode Island. The formation of the surface low at the system’s triple point (where the warm, cold and occluded front meet) will allow for showers to become more widespread as they push eastward.