Forecast discussion: Thursday started off quite differently than Wednesday in Boston. Yesterday, the capital city experienced bright sunshine for much of the day. However, we have seen more clouds in the sky, with just a few hours of partly cloudy conditions, according to the observations at Logan Airport. Thanks to the cloud cover and the easterly winds off the cooler ocean, temperatures today only reached 60 degrees for a high. As we move into the weekend, our temperatures will become above average. However, we will have to pay with some dreary days on the weekend.
Right now, a very weak cold front is coming south from Northern New England. Meanwhile, a strong warm front pushing into the Mid-Atlantic will struggle to move northward. Due to a weak high pressure ridge and the cooler air, the warm front will remain south of eastern Massachusetts on Friday. But, we will see some scattered showers passing over the state by the middle of the morning. We will see more widespread shower activity by Friday night, as the warm front moves into the region. An isolated thunderstorm is very possible, with some gusty winds.
By Saturday, the warm front pushes north, and our high temperatures will reach the lower 70’s. The cold front associated with this low will also begin to push east. The contrast with the warmer air meeting with the approaching colder air will create some isolated thunderstorms during the afternoon. By Saturday night, the low will push into Nova Scotia, and the cold front will dissipate. We will see shower activity end early Sunday morning. With south-southwest winds, temperatures will stay quite mild, with partly to mostly sunny skies.
By Monday, we will begin with limited sunshine, as a low pressure system over the Northern Plains slowly pushes a warm front into New England. We will see scattered showers by the afternoon, and become more isolated into early Tuesday morning. The cold front will be blocked by a strong ridge in the Atlantic, but showers ahead of the front will begin by the middle of Tuesday afternoon. It is in this time period that the computer models begin to disagree with their scenarios.
The American model keeps slowly pushing the cold front through, but another low pressure system forms off the coast of North Carolina. The low will be picked up by the front, and this low will bring some heavier rainfall early Wednesday night, and continuing into Thursday. But, the European and United Kingdom models show the front passing, with no extra low. So, we would only see scattered showers Wednesday night into Thursday. For now, I believe the American model is strengthening this second low too much, and creating too much precipitation. I am going to stay a little conservative, and give us scattered showers Wednesday night, with isolated showers into Thursday. After the cold front pushes through, high temperatures will drop into the middle 60’s by Thursday.
72 hour forecast:
Tonight: Overcast with possible patchy fog along the eastern coastline. We will see a low of 50.
Friday: Cloudy with scattered showers by mid-morning. We will see a high of 60. Winds will come from the east-southeast at 9-12 mph.
Friday night: Mostly cloudy with scattered showers and a low of 54. A widely isolated thunderstorm is possible. Winds will come from the south at 9-12 mph.
Saturday: Cloudy with widespread showers and isolated thunderstorms with a high of 72.
Saturday night: Scattered showers end by 2 a.m. and a low of 57.
Sunday: Partly to mostly sunny and quite mild with a high of 74.
Sunday night: Partly cloudy with a low of 55.
Monday: Partly sunny with scattered showers/light rain by noon. Highs 74-77, lows 56-59.
Tuesday: Overcast with isolated showers by midnight, with widespread showers/light rain by mid-afternoon. Highs 73-76, lows 53-56.
Wednesday: Isolated showers during the morning, with widespread showers by the early evening. Highs 66-69, lows 55-58.
Thursday: Isolated showers. Highs 65-68, lows 50-53.