Cooler and less humid air is streaming into New England Tuesday, delivering plenty of sunshine after the early morning downpours in southern New England. In northern New England, scattered showers and thunder continue bubbling up at times Tuesday.
Storms could pop up in Maine throughout the day and later in the afternoon for the lakes and mountains of New Hampshire and Vermont, all driven by cold air and atmospheric energy aloft. There's enough cold air at cloud level that some storms may even contain hailstones and gusty winds. As a result, Tuesday may not be the best day for a mountain hike owing to lightning potential, but the rest of the week looks spectacular.
The great weather of dry air, mild daytime high temperatures and cool overnight low temperatures comes as a sprawling area of high pressure – fair weather – builds over the northeast United States. It will move west to east slowly, cresting over New England by Thursday night. When fair weather centers move overhead, the wind often becomes quite light and that’s expected Wednesday and Thursday nights.
Combined with a clear sky and light wind, we’ll find overnight valley fog and fog developing near water bodies of interior New England, burning off in the first few hours each morning. The deeper valleys of the North Country are likely to dip into the 30s! Farther south, 30s aren’t as likely, but several sub-50° readings are likely on both Thursday and Friday mornings.
While dry air cools quickly at night, it also warms quickly with sunshine, which is why our First Alert Weather Team still expects high temperatures to rise to around 80° both Wednesday and Thursday, and into the 80s Friday. A southerly wind flow develops Friday into Saturday, bringing mid-summer warmth back to New England.
We'll feel an increase in humidity Saturday as high temperatures near 90°, then more humidity with scattered thunderstorms returning to the forecast Sunday. Although the cool nights bring notions of fall, the 10-day definitely looks more like summer than autumn, with daytime highs still around or over 80° for most of us next week.