Forecast discussion: A weak low pressure system moving through northern Vermont at the moment provided Boston with low clouds, mist, and drizzle on Thursday. As the low moves offshore, a high pressure system in the eastern Great Lakes will slowly clear our skies, and provide us with some nice weather on Friday. However, the “unofficial” end of summer this weekend will come to a wet end.
We will begin to see increasing clouds Friday evening, thanks in part to a weak disturbance over the western Great Lakes. It will provide us with overcast skies early Saturday morning, and we may see a passing shower. The second low will help bring southwest winds and more moisture into the Northeast over the weekend, increasing our humidity. This will help keep more moisture in the air, and as a warm front passes over us Saturday afternoon, we may see off and on showers and a possible thunderstorm. This off and on activity will persist into Sunday as well. So, I am not saying if you have to cancel the cookout, but you may want to keep an eye to the skies from time to time.
I believe the worst day of the weekend will be Monday. As a cold front slowly inches closer to Southern New England, I see the best chance for showers and thunderstorms to be by mid-afternoon. The chances for precipitation will continue into Tuesday morning, as the cold front passes through central Massachusetts by the afternoon. The front will pull offshore by the evening, and we will see clearing skies. Sunshine will return on Wednesday, although a weak disturbance may bring a passing shower next Thursday. However, none of the computer models suggest the disturbance will have a lot of moisture associated with it. For now, I will call for partly sunny skies.
72 hour forecast:
Tonight: Overcast until midnight, with partial clearing. We will see a low of 60.
Friday: Mostly sunny in the morning, with more clouds than sun through the afternoon. We will see a high of 80. Winds will come from the southwest at 7-10 mph.
Fenway Park Forecast (7:10 p.m. vs. Chicago White Sox): Mostly cloudy, 73.
Friday night: Mostly cloudy and more humid with isolated showers and thunderstorms after 1 a.m. and a low of 69. Winds will come from the west-southwest at 7-10 mph.
Saturday: A morning shower or thunderstorm, before we see partly sunny skies and a high of 82.
Saturday night: Mostly cloudy with widely isolated showers and a low of 70.
Sunday: Mostly cloudy with off and on showers and an isolated thunderstorm. We will see a high of 81.
Sunday night: Off and on showers with a low of 72.
Labor Day: Overcast with possible showers and isolated thunderstorms through the day. Highs 79-82, lows 66-69.
Tuesday: Showers ending in the early afternoon, with cloudy skies for the rest of the day. Highs 77-80, lows 62-65.
Wednesday: Mostly sunny. Highs 77-80, lows 59-62.
Thursday: Partly sunny. Highs 76-79, lows 60-63.