Forecast discussion: As of 8:05 p.m., a line of showers are passing over Boston at the moment. Meanwhile, a small cluster of thunderstorms are passing over eastern Connecticut. The thunderstorms are due to a cold front moving through eastern New York. The cold front will pass through eastern Massachusetts early Sunday morning. So, we will see the risk for some isolated thunderstorms until 1 a.m. After that time, we will see scattered showers until the middle of Sunday morning.
However, if you have any outdoor plans with or for Mom today, you need not fear. A weak area of high pressure will build over Southern New England, bringing bright sunshine by the afternoon. We will also keep the very warm temperatures, as highs reach the middle 70’s. We will keep dry weather for Sunday night, but we will return to an unsettled pattern by Monday.
A new low pressure system now located over the Northern Plains will slowly move east. As it approaches the Northeast U.S., it will start off over northern New England. A weaker low in the central U.S. will help bring some scattered showers by Monday afternoon. The second low will move offshore, so the precipitation will come to an end Monday night. But, the first front will actually move southward. We call this a “back door” cold front, as it is unusual to have cold fronts move north to south. Our temperatures will be much cooler by Tuesday.
The back door cold front will also shut down the precipitation for a small period of time. This is due to a weak high pressure ridge behind the front. The ridge will cut off the precipitation on Tuesday. By Wednesday, the ridge will begin to break down, allowing for the moisture to move back into the region. The cold front will get stalled, so we will see scattered showers into Thursday.
The American model once again is developing a low pressure system off the Mid-Atlantic coast for Friday. This low will bring some heavy rain and scattered thunderstorms. The European model is not showing as much precipitation. For now, I will go with the worst case scenario, as the American model has been consistent with this forecast for the last few days. As we head into Saturday, the moisture moves offshore, but a weak disturbance moves into New England and brings the threat for more showers by Saturday evening. After Wednesday, temperatures will return to seasonable conditions.
72 hour forecast:
Tonight: Scattered showers and thunderstorms through midnight. Isolated showers expected after midnight. Patchy fog is expected, especially along the coast. We will see a low of 59.
Sunday: Showers end by 9 a.m. with mostly sunny skies by noon. It will be quite warm and breezy with a high of 77 and west-northwest winds of 14-17 mph. We could see occasional gusts up to 25 mph.
Sunday night: Partly cloudy with a low of 55. Winds will come from the west-southwest at 8-11 mph.
Monday: Partly sunny in the morning with scattered showers or light rain by 3 p.m. We will have a high of 77.
Monday night: Isolated showers until midnight but remaining mostly cloudy. We will see a low of 53.
Tuesday: Partly sunny and cooler with a high of 61.
Tuesday night: Mostly cloudy with a low of 47.
Wednesday: Overcast with showers arriving by the late morning. Highs 58-61, lows 53-56.
Thursday: Scattered showers. Highs 67-70, lows 55-58.
Friday: Mostly cloudy with moderate to heavy rain and scattered thunderstorms until noon, then tapering to showers through the afternoon. Mostly cloudy skies by the evening commute. Highs 65-68, lows 55-58.
Saturday: Overcast with possible showers by the early evening. Highs 66-69, lows 54-57.