New England Weather This Week: Turning Summer-Like

This week will see firm ridging build through mid-week, bringing summer weather. Very warm temperatures and high humidity is expected before more unsettled weather returns late in the week.

MONDAY

The first half of the week will see dry and tranquil weather as ridging takes control at the surface and aloft. Monday will be a transition day as the upper-level low remains to the north of New England with a trough extending back into the region. This will mainly allow for some cloud development across the region this afternoon. Isolated showers will be most likely across eastern Maine, closest to the trough. The trough will keep cold temperatures aloft around, which will limit heating today, though it will still be warmer than the weekend.

TUESDAY & WEDNESDAY

High pressure will firmly be in control both days as the trough completely loses its grip. The ridge of high pressure will be centered to New England's south and west. This is very favorable placement for very warm and humid conditions to advect into New England, and that's just what will happen. Temperatures aloft will be warming throughout the first half of the week, with 850mb (about 4,700 feet above sea level) climbing into the 60s by mid-week. With deep ridging and a well-mixed atmosphere, this will translate to widespread 80s at the surface.

500mb heights on Wednesday afternoon, showing a warm ridge building over the east, finally flipping the pattern from the ridge-in-the-west-trough-in-the-east setup

Tuesday will likely be a notch cooler than Wednesday as temperatures aloft will still be warming to their maximum levels (850mb temperatures will likely be in the 50s as opposed to the 60s). Highs will likely top out in the 70s for most, with some making a push for the low 80s. Wednesday will be well into the 80s for most, with some making a push for 90°. There are currently moderate chances of New England's typical warm spots cracking 90 for the time this season, those spots being the Connecticut River Valley, Merrimack Valley and maybe Champlain Valley.

Below: RGEM showing potential temperatures Wednesday afternoon:

Despite these warming temperatures, Tuesday will start off on the cool side. With high pressure building, it will create clear skies and light winds, which will allow for efficient radiational cooling conditions. Morning lows on Tuesday will be in the 40s for many with 30s (and patchy frost) possible in northern valleys. These chilly morning lows will be erased very quickly after sunrise. The pressure gradient will be weak both days, allowing for afternoon sea breezes to develop, keeping the coasts cooler during the daytime.

THURSDAY & FRIDAY

By Thursday, the ridge will begin to break down as an area of low pressure and attending cold front approach New England. This cold front will be slow-moving and in the vicinity of New England through the rest of the week. This front will allow scattered showers and storms to pop up both Thursday and Friday.

As of now, the better chance for showers and storms on Thursday will be across northern New England with a better chance for southern New England on Friday. The coverage and intensity of these showers and storms remains a question. Whether its more instability-driven pop-up activity or more organized and numerous activity associated with an area of low pressure will be something to watch.

Both heat and humidity will likely remain elevated ahead of the cold front on Thursday. This will help provide ample instability and fuel for showers and thunderstorms. With forcing from the front, some of these showers could produce torrential downpours given the high-moisture environment. Thursday will likely be the warmest (and most humid) day of the week for many, with temperatures into the 80s to low 90s for everyone despite the potential increase in clouds. Friday will begin a cooling trend as more unsettled weather takes hold.

WEEKEND

That cold front, which initially looks to get held up across northern New England, will likely cross the region later Friday into Saturday morning. The exact timing of the frontal passage will determine when the best chance for widespread shower activity will be later Friday through Saturday. At this point, Saturday does appear unsettled as the front pushes through, but it could end up like last Saturday, where only a part of the day sees higher rain chances.

As of now, the frontal boundary does look to clear out by Sunday, though this timing can still change at this point. The second half of the weekend will likely feature a drying trend with cooler temperatures on the other side of the front. At this point, the cool-down behind the front is more likely to bring New England back to more seasonable levels for early June.