Forecast discussion: A high pressure ridge in the Atlantic Ocean helped us receive sunny skies and humid conditions here in Boston on Sunday. However, as we move into the early part of the week, we may be seeing some very strong thunderstorms roll through eastern Massachusetts.
Currently, a cold front passing into the Ohio River Valley has created a few severe thunderstorms over Albany, New York and western Massachusetts. This activity will move over the capital city by early Monday morning. We will see scattered showers and thunderstorms, but it will not be an all-day event. However, due to some very cold air behind the front, as well as an upper level low moving over New England, the thunderstorms may be strong or severe at times. This will include lightning, gusty winds, and small hail, along with periods of heavy rainfall.
The worst part of this cold front will come on Tuesday. The front is expected to move over Southern New England, and then stall. So, the best risk for strong to severe thunderstorms will be on this day. The front will slowly push through to the coast by Wednesday morning, but the strong high pressure system in the Atlantic will cause the front to slow its progress. So, it will not be until Wednesday evening that we see the end of all the precipitation.
High pressure will settle over the Northeast U.S. by Wednesday night, giving us mostly sunny skies and cooler temperatures for the middle of July. The cooler temperatures are due to the upper level low bringing down much colder air into New England. Our high temperatures for the rest of the week will only be near or just over 80 degrees.
As we head into the new week, the computer models are showing a weak area of low pressure moving from the Southeast U.S. into the Mid-Atlantic by Saturday afternoon. We may see some showers and possible moderate periods of rain by early Sunday morning. The rainfall will continue throughout the day, making a possible end to six straight Sundays without any precipitation.
72 hour forecast:
Tonight: Scattered showers and thunderstorms by 11 p.m. Patchy fog expected along the coastlines, including the Cape and Islands. We will see a low of 72.
Monday: Scattered showers and thunderstorms. Some thunderstorms could be strong to severe. Thunderstorms may be accompanied with gusty winds and small hail. It will be humid with a high of 84 and south-southwest winds of 10-13 mph.
Monday night: Showers/thunderstorms with patchy fog and a low of 73. Thunderstorms may be strong, with gusty winds, small hail and periods of heavy rain. Winds will come from the south-southwest at 9-12 mph.
Tuesday: Showers and thunderstorms expected. Thunderstorms could be strong to severe. We will see a high of 84.
Tuesday night: Showers/thunderstorms continue with a low of 67.
Wednesday: Showers/thunderstorms end by 9 p.m. We will have a high of 77.
Wednesday night: Partly cloudy with a low of 63.
Thursday: Mostly sunny. Highs 80-83, lows 61-64.
Friday: Mostly sunny. Highs 80-83, lows 61-64.
Saturday: Mostly sunny in the morning, with increasing clouds in the afternoon. Highs 80-83, lows 63-66.
Sunday: Mostly cloudy with scattered showers by the early morning. There may be periods of moderate to heavy rain. Highs 79-82, lows 65-68.