272 days have passed since Boston’s temperature nudged 90 degrees. That long string will be broken today as I predict the city’s high will be 91. By the time the heat is turned off late Sunday, it will be an official heat wave containing the required 3 consecutive days of 90 degrees or higher. Just short of any new record highs, tomorrow and Saturday will be closely matched for the hottest weather in this stretch with 92-94 degrees expected on both days. After that, a gustier wind with a bit more of a southerly component may prevent the temperatures from reaching 90 degrees in some spots especially closer to south-facing coastal locations on Sunday. The previous heat wave for the city occurred on July 13-15 while other locations away from the ocean got heat wave conditions a few times through August. Thankfully, the humidity, although much more noticeable, is not expected to become oppressive this go-around. Dewpoints will climb into the high category from time to time at 65-70 degrees. Overnight minimum temperatures will be mostly in the middle 60s in many of the suburbs to the lower 70s in Boston. Any late night fog in lowland locations will burn off swiftly after sunrise.
After last evening’s widespread thunderstorm activity which released varying amounts of drenching rain and frequent lightning, there is a much lower risk for just a few spotty boomers this afternoon and early evening mainly focused near a weakening boundary draped across southern New England. The boundary will dissolve and over the following couple of days, the risk shifts to areas farther and farther north and west of Boston. On Sunday, an approaching vigorous cold front from the Great Lakes and NY/PA will trigger a sold swath of showers and boomers pressing eastward. This action is slated to push into northwestern New England later Sunday afternoon and evening with a shift toward the coastal plain by Monday morning. The front is likely to decelerate and become quasi-stationary in eastern sections through most of Monday then gradually move offshore Tuesday morning. Consequently, expect occasional showers with some lightning and thunder much of Monday with a few lingering lighter showers exiting Tuesday morning. High pressure will build into the region at midweek so Wednesday and Thursday will be fine days with low humidity and a nice breeze as temperatures reach seasonable levels in the middle 70s.
Todd Gutner publishes his blog early this evening and I shall return early tomorrow morning.
Make it a great day!