After a handful of communities joined the Century Club by topping out at or over 100° Monday afternoon, the temperature will be a few degrees cooler…but we won’t notice the difference. An increase in humidity creates a heat index around 100° for the metropolitan areas of southern New England Tuesday.
Farther north, a round of morning showers combined with more clouds will keep temperatures cooler than southern New England. But that same disturbance aloft – driving a cold front at the surface – will trigger scattered afternoon thunderstorms in southern New England, particularly from 2 or 3 p.m. onward.
Not everyone will see Tuesday afternoon thunder. But with temperatures in the 90s and dew point temperatures around 70, which indicates plenty of moisture in the air, any storms that develop will have the potential to grow strong off the heat and humidity with torrential downpours, lightning and locally strong or damaging wind gusts.
Storms won’t reach Cape Cod until night, when most of them will be weakening as the cold front driving them slows. It will slow so much that humid air is unlikely to be completely replaced on the Cape and Islands and immediate south coast.
The rest of New England will feel a huge difference with much more comfortable air Wednesday, even as temperatures still rise to 90 degrees.
Another disturbance and associated cold front drops into New England later Thursday, prompting a few more thunderstorms. It will also usher in a fresh shot of even more comfortable, cooler air for Friday and the weekend – a splendid-looking weekend.
Humidity will return early next week with a developing southerly wind flow. We’ll need to watch that flow of air because, as of this writing, there’s a tropical disturbance way out in the central Atlantic that may strengthen as it churns west.
That could represent a healthy slug of moisture, a piece of which could migrate north early next week to enhance showers and thunderstorms Monday and Tuesday. Another cold front is expected to once again sweep in more comfortable and drier air around the middle of the week, at the end of our exclusive First Alert 10-day forecast.