Humidity came roaring back with the southwest wind today. Dewpoints reached into the upper 60s around Greater Boston, while elsewhere we saw dewpoints “only” in the low 60s. What was at play here?
South winds carried the humid air up from Narragansett Bay where the water temperatures have surged into the mid 60s already! Cape Cod/Vineyard and Nantucket Sounds all show water temps equally as warm, but clouds kept the sun away, and there wasn’t as much evaporation to contribute to the increase in humidity. This ocean/atmosphere connection drives our “sticky surges” in the summer. As the water warms, the sea breeze will become less and less of a cooling influence, and more of a “humidifier” in the coming months.
A lone downpour popped up this afternoon in Southern NH. Big rains came to Hampton and the northern end of Seabrook. This was a flare up, as opposed to the organized storms that could sweep in overnight.
This batch of rain and thunder is riding a quick-moving jetstream and will hit some communities hard after midnight. Expect downpours, lightning and thunder through the wee hours of the night. Not guaranteeing all hits here, but a couple of places may pick up significant water for the lawns and gardens.
Humidity lowers, the wind turns northwest, but we’ll still bake under hazy sun tomorrow. Lots of upper 80s and low 90s. Oddly, the humidity is lower tomorrow than today!
Thereafter, the forecast glistens with sunshine and dry air. I’m seeing some blocking over Nova Scotia and Cape Breton Island, so that puts us in the sun and low humidity. Confidence is running high for a rain-free stretch from Wed PM through the weekend.