What to Know
TUESDAY: Humid air fuels scattered showers and thunderstorms in Vermont and New Hampshire, later reaching Massachusetts.
TUESDAY AFTERNOON: Thunderstorms can be expected in central Massachusetts and across Connecticut.
LOOK OUT FOR: Heat advisory in Boston, flash flood watch in parts of New England, prolific lightning.
Flash flood watches are in effect around New England Tuesday as the ingredients for severe thunderstorms across the region come together.
Expect locally dense fog once again Tuesday morning with temperatures starting out in the 60s and 70s.
We also have very humid air in place to fuel powerful thunderstorms on a cold front progressing from the northwest to southeast Tuesday. We may have a solid squall line develop.
First thing in the morning, scattered showers and thunderstorms will strike in Vermont and New Hampshire, tending to consolidate by late morning across southern New Hampshire into western Massachusetts.
For the afternoon, we likely have a line of thunderstorms along the Maine Turnpike down to central Massachusetts and across much of Connecticut. That line will sweep east to the coast by dinner time. Wind ahead of the front is from the south at 10 to 20 mph, but any thunderstorm can generate gusts in excess of 60 mph, with locally damaging wind.
Rain could briefly be torrential, and prolific lightning is likely. Flash flooding is also possible, with local 2-inch or more rainfall in less than one hour.
The line of storms should be moving off the coast and out to sea by sunset.
Then we have warm, but much less humid air, coming in for most of the rest of the week.
High pressure from Canada brings sunshine and warm afternoons in mid-80s, and nighttime lows in the 50s to low 60s.
The weekend should start off nice with sunshine, but humidity builds once again, and a front of may bring showers by Sunday.
Early next week we may have a front stalled here in New England with tropical moisture streaming northward, with the chance of occasionally heavy rain for a couple of days. We could really use the rain, but that's still quite a ways out.