I don’t know about you but for me, this past weekend was gross…the air was so oppressive that the rain from thunderstorms didn’t even make it better…in fact, it made it worse! That tropical air and associated downpours have been swept offshore by a front and the air has dried out nicely on WSW flow throughout the column behind it. Dewpoints have scaled back from 70+ over the weekend to around 60 now…we won’t see relief from the hot weather but at least we are from the oppressively humid weather.
Unfortunately, this relief is only temporary as dewpoints will be climbing through the middle of the week. An approaching 500mb trough will work out of the Great Lakes and into the Northeast…out ahead of it SSW flow will enhance and guide very sticky air back into the region. The cooler air aloft associated with the trough and a surface front will provide enough lift by midday Wednesday for soaking showers and thunderstorms to develop and last through the evening. Much like the ones over the weekend, we could be dealing with more street flooding issues.
On Thursday, the front will be stalling near or on the coast during he morning hours providing a focus for weak low level lift…which by itself may not be enough to trigger additional showers and storms but the axis of the 500mb trough won’t be through until early in the afternoon and therefore the air will still be unstable enough to keep showers and storms in the forecast for the first half of Thursday. While the action will be reduced from Wednesday there still looks like a threat especially in Eastern MA. Timing will be critical and if the front / upper trough slow down any more and their passage coincides more with the maximum daytime heating then we’ll have to beef up the thunderstorms threat even more on Thursday.
Westerly flow will take hold of Friday providing hot and dry conditions…highs should reach 90 in many spots with offshore / downsloping winds and an 850mb temp around +16C. The humidity will back off too for a drier type heat to finish up the workweek.
The weekend shows signs of more unsettled and very humid weather…with another digging East Coast trough shooting muggy air and moisture up the Eastern Seaboard. This will provide another round of weekend soakers. Timing and specifics are sketchy at this point but right now soaking downpours can be expected Saturday afternoon through Sunday morning.