18/06/2025
Thursday will be very summer-like with two warm season features incoming: heat and thunderstorms. Both of this will be set up by a frontal system first lifting a warm front across the region followed by a cold front late in the day.
HEAT
New England will remain in the warm sector on Thursday, with conditions more favorable for higher heat and humidity compared to today. Temperatures aloft will peak, allowing for the hottest day of the week. Widespread highs in the 80s to near 90° are possible for southern and central New England. With dew points well into the 60s to near 70°, feels-like temperatures will be well into the 90s for areas within the heat advisory (shown on the alerts map below). The northern tier will be kept a notch cooler, but widespread highs in the 80s are likely just about everywhere.
STORMS
As of now, the western half of New England will have the best chance of seeing storms erupt in the afternoon. How far east the main line of storms can push in the late afternoon and evening before fizzling out will be the biggest question. At this point, it does look like storms will begin to steadily lose steam east of the Connecticut River/Worcester Hills. The main storm threat will likely be in the 3pm-7pm range for western New England and the 5pm-9pm range for eastern New England.
Strong to damaging winds gusts will be the greatest threat within storms as strong winds in the upper-levels will be present. Downdrafts within the storms will help bring these winds down to the surface. Both large hail and brief tornadoes are secondary threats. While conditions aren't really primed for large hail development, ample wind shear is present which will help hail. With linear storm motions and elevated winds shears, it's possible New England sees its first tornado of the season, but this remains a very low threat overall. Downpours and localized flooding will be possible as well.
The main ingredients for severe storms will all be present and ample. These ingredients begin shear, moisture and instability. The biggest limiting factor (and it may be a significant limiting factor; if storms end up few and far between, this is to blame) is the late timing of the cold front, which has trended later. This front will be the main source of lift, and will likely not cross New England until late in the day, most likely in the late afternoon through the evening. Most guidance shows much of New England being capped on instability until the cold front arrives. The eastern half of New England may not see the cold front begin to arrive until later in the evening, and by then, storms will begin to weaken. This is why the best chance for severe storms will be across Vermont, western Massachusetts and western Connecticut with chances steadily dwindling moving eastward. Some areas in southern New Hampshire, eastern Massachusetts, Maine and Rhode Island may not see much of any storm activity until very late in the day.
This late timing of the cold front is the main reason why a severe weather outbreak is not expected despite favorable conditions. Scattered severe storms are likely, but plenty of areas across New England will likely see little to no activity as well. Pre-frontal storms are expected to be isolated in nature, but any storm that manages to form in the early afternoon before the cold front arrives will likely become strong to severe quickly.
