Fresh air has taken hold of New England for the day. It's less humid because the dew point temperature, which measures the amount of moisture in the air, has dropped significantly.
The difference in the air was palpable as soon as the early morning hours Wednesday, with most communities 10 to 20 degrees cooler than the same time Tuesday morning. Although sunshine will warm the dry air to around 90° by the afternoon, the lack of humidity negates any worry of heat index beyond the actual temperature.
The presence of dry air means we all have a greater than 90% chance of staying dry, save for the islands of Massachusetts, where a few leftover morning showers accompany the still-ongoing change of air. In fact, while humid air will briefly ease on the Cape and Islands, it quickly returns from the south Wednesday night. This will not only put the south coast back into soupy air but will also result in areas of fog and a few overnight rain showers in central and southern New England.
By Thursday morning to mid-day, all of New England is back into humidity. A truly tropical feeling will permeate southern New England, where scattered afternoon showers are expected to develop in that moist air, acting as fuel for potentially strong thunderstorms.
This time around, humidity is short-lived with a cold front following the Thursday afternoon storms and delivering less humid air as soon as Friday. Showers ending from northwest to southeast could last at least in scattered form into Friday morning for southeastern New England, particularly the Cape and Islands.
By Friday afternoon, the less humid and comfortable air will be in place, leading to an incredible start to the weekend. The only weekend weather concern our First Alert Weather Team has right now is an increasing chance of showers or thunder by Sunday afternoon or evening. Humid air will be pressing northward again, attempting a return to New England that eventually succeeds by Monday.
In fact, the first half of next week we not only will have our eyes turned to humid air progressing on a southerly wind, we’ll also be watching the moisture associated with what is, as of this writing, Potential Tropical Cyclone Nine and seems likely to be classified as Tropical Storm Isaias soon.
This storm is expected to be near or over Florida this weekend, and represents, at the very least, a large swath of tropical moisture that may be able to enhance showers and thunderstorms even here in New England next week. Then another cold front approaches to dry us out for the second half of next week in our exclusive First Alert 10-day forecast.