Forecast discussion: Once again, the oppressive humidity and bright sunshine helped to create some thunderstorm cells over central Massachusetts, along with Bristol County. At the moment, some strong thunderstorms have moved over New Bedford, MA, with growing thunderstorm cells to enter northern Rhode Island. This activity will continue for the next 4-5 hours, as we maintain daytime heating. At this time, there are no thunderstorm cells or even shower bands near Boston.
As we approach Wednesday, a weak high pressure system entering the Mid-Atlantic States will give us some dry air over our part of the atmosphere. This will keep any showers or thunderstorms from developing. However, the air quality will be poor in ozone. So, an Air Quality Alert will be in effect from 11 a.m. to 11 p.m. for southeastern Massachusetts, including the Cape and Islands. Expect heat indexes to reach the middle to upper 90’s by tomorrow afternoon in this region.
We will keep the sunshine for Thursday morning, but once again there will be a risk for some strong thunderstorms by the late afternoon or early evening. A weak cold disturbance will pass through New England by Thursday night, so we will keep the chance for more precipitation into Friday morning. By Friday afternoon, the front will move offshore, allowing for a high pressure ridge to bring dry weather for Saturday.
By Saturday night, a cold front will pass through New England, giving us the risk for scattered showers and isolated thunderstorms through Saturday night and Sunday morning. We will see mostly sunny skies by Sunday afternoon. A new low pressure system may bring more showers and thunderstorms by Monday morning.
As you can see, the temperatures will remain quite hot through the forecast period. An upper level ridge will stay just west of New England, keeping us on the eastern side of the ridge. There are no other upper level features coming towards the eastern U.S. to help break down the ridge.
72 hour forecast:
Tonight: Slight chance of showers/thunderstorms until midnight. After midnight, partly cloudy skies expected while remaining humid. We will see a low of 72.
Wednesday: Mostly sunny, hot, and humid with a high of 91. Winds from the northwest will shift to the southeast at 8-11 mph by the afternoon.
Fenway Park Forecast (7:10 p.m. vs. White Sox): Partly cloudy, 85.
Wednesday night: Partly cloudy with some high and mid-level clouds arriving by sunrise. It will remain oppressive with a low of only 73. Winds will come from the west-southwest at 7-10 mph.
Thursday: Mostly sunny with possible late afternoon/early evening showers/thunderstorms. We will see a high of 90.
Thursday night: Scattered showers/isolated thunderstorms with a low of 72.
Friday: Isolated showers/thunderstorms until 11 a.m. with afternoon sunshine. We will see a high of 88.
Friday night: Partly cloudy with a low of 69.
Saturday: Mostly sunny through the morning, with increasing clouds by the early afternoon. Showers and isolated thunderstorms are possible by 7 p.m. Highs 87-90, lows 68-71.
Sunday: Overcast with scattered showers/thunderstorms until 9 a.m. Mostly sunny skies expected by 1 p.m. Highs 85-88, lows 67-70.
Monday: Overcast skies by early morning, showers/thunderstorms by 10 a.m. Highs 86-89, lows 68-71.
Tuesday: Showers/thunderstorms end by 10 a.m. with partly sunny skies. Highs 85-88, lows 67-70.