Metro Boston and the suburbs north and west:
A cold front, associated with surface low pressure in Canada, will track across New York State Thursday and is forecast to extend from northern Maine to the lower Hudson Valley by mid afternoon. The front is expected to slowly cross southern New England late Thursday and Thursday night, stalling near southeast Massachusetts and Cape Cod Friday. Low pressure will ripple along the front near Long Island and the south coast of New England Friday and hopefully continues to track offshore Saturday. High pressure follows in the wake of the cold front and departing low.
The cold front will be the focus for additional showers and thunderstorms Thursday. Most of this week the heavier shower and thunderstorm activity has been to our west and south. Last evening the heavy activity diminished quickly and dried up as it progressed toward the metro Boston area, especially for the neighborhoods north of the city. But, the shower activity should make it all the way to the coast Thursday and into the evening hours before coming to an end. A few downpours are possible in some locations with the possibility of a few thunderstorms becoming strong to severe. It will remain warm and humid ahead of the front with temperatures climbing into the mid 80s during the afternoon. Lows tonight in the mid 60s.
Once the front slides south of the forecast area the winds turn north and then northeast, bringing in cooler and somewhat less humid air. However, it remains cloudy with showers and possibly a few thunderstorms on Friday and Friday night. Highs close to 70 degrees on the coast to low and mid 70s inland. Overnight lows in the low 60s.
The weekend forecast mainly hinges on how far the front and disturbance move away and the timing as to when this occurs. There is some discrepancies within the computer models on exactly what will happen so it is still a shaky forecast for the weekend, especially Saturday. Expect mostly cloudy skies Saturday with a chance of showers. Highs in the mid 70s to near 80 degrees. Drier at night, under a partly cloudy sky. Lows in the mid 60s.
Sunday will turn out partly cloudy and milder with highs into the low and mid 80s, as high pressure takes over. Less humidity will be a welcome treat for the weekend, with Sunday looking to be the better of the two weekend days overall.
As we move into the new work week on Monday it appears another bout of very warm and humid weather returns. Highs well into the 80s.