Forecast discussion: A cold front now passing through western Massachusetts will bring some showers and light rain over Boston after midnight. Some areas may see a heavy period of rainfall for a brief period of time. All shower activity will end by the late morning. We will develop a westerly breeze by the afternoon, as high pressure ridging tries to bring some sunshine back before the end of the afternoon. Temperatures will near 70 for a high, but we will begin to see a trend of true autumn weather.
The high will give us nice weather on Saturday. A long wave trough in the upper levels of the atmosphere will begin to shift from the central U.S. to the east coast. This will allow for northwest winds at the surface, and cooler air to come down from Canada. Also, a weak disturbance will pass through the area Saturday night, giving us the risk of some scattered showers until dawn Sunday morning. We will see skies clear with more sunshine by Sunday afternoon.
Skies will remain mostly sunny, but temperatures will struggle to reach the lower 60’s during the daytime. A new cold front will pass though by Tuesday, with the chance for some more scattered showers by the afternoon. The showers will end by early Wednesday morning, with high pressure giving us mostly sunny skies. By this time, we will begin to feel the coldest temperatures of the year, with a chance at seeing some frost northwest of Boston. The best chance may be in Worcester County by Wednesday night.
72 hour forecast:
Tonight: Scattered showers and light rain arriving after midnight, with patchy fog developing. We will see a low of 59.
Friday: Showers and light rain ending by the late morning, but becoming breezy, with clearing skies and some sunshine by the afternoon. We will see a high of 71 with west winds of 13-16 mph.
Friday night: Partly cloudy and cooler with a low of 50. Winds will come from the west-northwest at 7-10 mph.
Saturday: Mostly sunny and slightly cooler with a high of 67. Increasing clouds expected in the late afternoon.
Saturday night: Overcast with scattered showers after midnight and a low of 49.
Sunday: Isolated showers end by 7 a.m., with partly to mostly sunny skies and a high of 62.
Sunday night: Partly cloudy with a low of 45.
Monday: Mostly sunny. Highs 60-63, lows 45-48.
Tuesday: Cloudy by the morning, with scattered showers by the afternoon. Highs 63-66, lows 42-45.
Wednesday: Showers end by 2 a.m. with mostly sunny skies. Highs 54-57, lows 38-41.
Thursday: Partly to mostly sunny. Highs 53-56, lows 38-41.