Temperatures soared above 80 Tuesday across Greater Boston with mostly sunny skies. On Wednesday, another piece of energy paired with an approaching secondary cold front will pass through the region from the west. The day will start off mostly sunny — then daytime heating will help surface air lift above the incoming front and condense into a couple of spot showers or general thunderstorms this afternoon and evening.
Clouds will fill in through the afternoon while winds stay between a modest 5 and 10 miles per hour from the northwest.
The cooler, dry air from the west will act as a wedge and push the lighter warm air above it. The warmer air, now pushed into the higher atmosphere, will interact with cooler air, condense, and form spot showers and thunderstorms. Rain should remain light, though a cell or two may have a brief downpour. Totals should remain around a quarter of an inch or less.
Highs across the city will drop a notch or two over the next couple of days as this cooler air settles in. You can expect today’s highs to settle into the mid-70s.
Highs on Thursday may likely only reach the mid-60s across the region, so be sure to have a sweater or light jacket on the commute in.
The low associated with this passing front will stall just off the coast later tonight and may keep light, scattered showers in place through Thursday’s morning commute.
Wednesday’s breakdown
Southern New England: More sun than clouds to begin the day until clouds arrive later in the afternoon ahead of an approaching front. Pop-up showers or a general thunderstorm may bring light rain to parts of Southern New England this afternoon, but any rain totals should be light. Highs will likely reach the low to mid-70s while winds stay mostly calm. Showers will remain broken and scattered but are likely to stick around through the evening.
Western Mass.: Partly cloudy skies will turn a bit more cloudy as the day progresses, with western Mass. seeing the front arrive first. Temperatures should reach the low to mid-70s across Springfield, Greenfield, Hartford, and New London, while the hill towns within the Berkshires will see temps closer to 70. Scattered showers can develop around midday and linger through the afternoon.
Cape and Islands: Mostly sunny to begin the day with temperatures pushing toward 70. The Outer Cape will stay in the mid-60s. Clouds will begin to fill out the sky this afternoon with scattered showers lurking through the evening. Winds should stay around 10 mph from the west. Many of the coastal sea surface temperatures by the Cape are now above 60 degrees.
Northern New England: With the front angling toward New England from the northwest, Vermont will see early morning showers around sunrise with mostly cloudy skies. New Hampshire and Maine will see scattered showers around midday. There will be a mix of sun and clouds throughout the day, with all three northern states becoming mostly clear by sunset. Temperatures will be cooler than Southern New England. Vermont stays in the upper 60s to low 70s, New Hampshire in the low 70s, and Maine seeing readings in the low to mid-70s, especially along the coast.
Ken Mahan can be reached at ken.mahan@globe.com. Follow him on Instagram @kenmahantheweatherman.