Forecast discussion: After a day of mostly cloudy skies around Boston, a low pressure system off the coast of North Carolina will continue to keep cloudy conditions for the area on Tuesday. The low will remain far enough offshore that we will not see any showers in the city, although the Cape and Islands will see showers through the afternoon. Meanwhile, due to the coastal storm and astronomical high tide, a Coastal Flood Advisory will be in effect from 9 a.m. to 1 p.m. Tuesday.
Once the low moves into the Canadian Maritimes Tuesday night, a weak ridge of high pressure will provide partly cloudy skies Tuesday night. We will begin Wednesday with sunshine, but we will once again see increasing clouds as we head through the evening hours. The clouds are in advance of a warm front, which is currently in the north-Central U.S. This front will bring milder air on Wednesday afternoon. We will see shower activity starting early Wednesday morning, and continue into early Thursday morning. The warm front will move into Northern New England Thursday afternoon, giving us a brief period of dry weather.
However, we will not be done with this system. The cold front will be slowly moving towards New England Thursday night, bringing another round of showers and light rain. We will see rainfall throughout the day, and the precipitation may mix or change to snow showers by early Saturday morning. The precipitation will end by mid-morning, and a strong high pressure system will help bring partly cloudy skies by the afternoon.
Behind the cold front will be some very cold air, which will keep temperatures in the middle to upper 30’s throughout the weekend. As we head into the beginning of next week, the computer models are watching a low pressure system developing near the Tennessee River Valley by Saturday night. The low will create a secondary low along a warm front, which will bring rainfall on Monday morning. As the warm front passes to our east, colder air will try to advance into New England by Sunday night. The precipitation may end as a wintry mix or snow showers by midnight. However, my confidence on the forecast after Sunday is quite low. Many computer models do not agree on the low’s track or location of the rain/snow line at this time.
72 hour forecast:
Tonight: Mostly cloudy with a low of 35.
Tuesday: Partly sunny with a high of 45. Winds will come from the north-northwest at 7-10 mph.
Tuesday night: Partly cloudy with a low of 32. Winds will come from the northwest at 7-10 mph.
Wednesday: Mostly sunny in the morning with increasing clouds during the evening. We will see a high of 45.
Wednesday night: Showers arrive around 1 a.m. with a low of 39.
Thursday: Passing showers end by the late morning, then mostly cloudy and mild with a high of 51.
Thursday night: Cloudy with showers developing around midnight with a low of 43.
Friday: Overcast with showers/rain. Highs 48-51, lows 33-36.
Saturday: Overcast with showers mixing with wet snow, but all precipitation ending by the morning. Partly cloudy skies expected by the afternoon. Highs 38-41, lows 24-27.
Sunday: Mostly sunny with increasing clouds in the evening. Highs 34-37, lows 25-28.
Monday: Showers/rain possible by the early morning, possibly ending as a wintry mix before midnight. Highs 37-40, lows 27-30.