Extended Heatwave...
These won't be the hottest temps we've experienced this season but this will likely be the longest hot stretch...with a potential seven-day heatwave for the interior! Towns like Westford, Northboro, Nashua NH, and Lowell to name a few touched or exceeded 90 degrees today, making this day one of prolonged hot stretch.
With the exception of the Pacific NW, much of the nation will be under a ridge of hot air strengthening a Bermuda High through the weekend and well into next week. This will pump heat out of the middle of the country and into the Northeast. Highs will be right around 90 for the next several days. Some coastal spots will see weak seabreezes so a true heatwave will be more difficult to obtain but still possible even in Boston. Humidity will also be steadily climbing through the weekend. Although the heat and humidity will be present both tomorrow and Saturday, there won't be much of a trigger to spark any thunderstorms so only isolated convection be possible. However, on Sunday, with a more potent vortmax diving in from the west and a pre-frontal trough, scattered storms are likely Sunday evening. Any that form will be very slow movers and will give a solid soaking...I'm sure lawns and gardens won't object.
The ridge looks to build even more through the middle of next week and highs will climb into the mid 90s by Wednesday. But that should be the last of the heat as a large cut-off upper level low will spin south from Eastern Canada...lowering heights will beat down the heat and the ridge for the end of next week.