Forecast discussion: After a beautiful Saturday in Boston, a weak low pressure system to our south and an incoming cold front will bring some cloudy, wet conditions to eastern Massachusetts for the next couple of days.
Right now, that area of low pressure is centered well south of Long Island, New York. During the overnight, this low will work northward, and position itself near Cape Cod, MA. The low may create a few showers after midnight, although they will remain mostly over the region. By Sunday morning, a cold front passing through Ohio has showers and periods of heavy rainfall ahead of it. This precipitation will arrive by the mid-afternoon, and will continue into the evening. An isolated thunderstorm is possible, and some areas may see street flooding due to heavy rainfall. The precipitation will weaken by Monday morning, with lingering showers right into the mid-afternoon. We should see a little sunshine before sunset.
By Tuesday morning, a strong high pressure system will bring seasonable temperatures and bright sunshine to New England into the middle of the week. By Thursday, a new cold front will slowly work its way into New England. The front will combine with a developing area of low pressure in the Virginias to bring showers and periods of rain by Thursday afternoon, which will last into Friday evening. We will see a brief period of dry weather, as the computer models bring more precipitation into the area by Saturday afternoon. It is from a low pressure system over the Ohio River Valley, with the precipitation well ahead of it.
Finally, Tropical Storm Dorian has dissipated. Throughout the day, drier air from an area of high pressure in the upper levels of the atmosphere began to weaken the tropical system. Also, the system was running into vertical shear, helping to tear the tropical apart. By this afternoon, Dorian no longer even had a center of circulation. The National Weather Service will send a Hurricane Hunter on Sunday to investigate the area, but the last advisory was sent at 5 p.m. this evening. Dorian was centered at 18.9N 54.7W, or about 550 miles east of the Northern Leeward Islands. It had maximum sustained winds of 40 mph, and was moving west-northwest at 28 mph.
72 hour forecast:
Tonight: Becoming cloudy with possible showers and periods of rain after 2 a.m. Patchy fog will develop along the shoreline. We will see a low of 67.
Sunday: Cloudy with showers ending by mid-morning, only to return by the mid-afternoon. We will see a high of 81 with winds shifting to the southeast at 7-10 mph.
Sunday night: Showers with possible periods of rain and isolated thunderstorms, along with patchy fog. We will have a low of 69 with south-southwest winds of 5-8 mph.
Monday: Lingering showers ending by the mid-afternoon with partial clearing before sunset. We will see a high of 84.
Monday night: Partly cloudy with a low of 63.
Tuesday: Mostly sunny with a high of 83.
Tuesday night: Partly cloudy with a low of 64.
Wednesday: Mostly sunny. Highs 83-86, lows 66-69.
Thursday: Cloudy with showers and possible periods of rain developing by the afternoon. Highs 81-84, lows 66-69.
Friday: Scattered showers through the day. Highs 83-86, lows 67-70.
Saturday: Partly to mostly sunny through the morning, with showers developing by the afternoon. Highs 83-86, lows 68-71.