This week will be a continuation of what New England has seen recently with generally unsettled weather, but low chances for all day washouts. The week will also see a distinct cooling trend after a warm day Tuesday (at least for southern New England).
MONDAY
Weak ridging continues for New England on Monday. A southwesterly flow will begin to bring a more mild air mass into the region, allowing for a warm-up compared to the past several days. Skies will see variable clouds with brighter times and cloudier times. Clouds associated with an approaching warm front will move into western New England by the afternoon.
Scattered showers with the front will break out by the evening in western New England before sliding east across New England into the first part of Monday night. Overall coverage of the showers will be rather low. Highs will be in the mid 60s to low 70s region-wide with Cape Cod and the Maine coast staying a bit cooler.
HRRR showing expected weather this evening:
TUESDAY
The warm front itself will overspread New England Tuesday morning, placing the region in the warm sector of an approaching system. This will allow temperatures to climb to more summery levels for the day. The front will likely bring a round of showers to northern New England in the morning. Showers may linger into the afternoon across the northern tier. Southern New England will likely see much more limited showers activity overnight Monday to Tuesday, ending by sunrise with some clearing in the afternoon.
Tuesday afternoon and evening will see thunderstorm/shower chances increase for much of northern New England as the cold front begins to approach. Lift and moisture will be present for storms, but instability and shear are bigger question marks. With that said, the chance for severe storms is low at the moment, but some stronger cells could develop with frequent lightning, torrential downpours and gusty winds.
GFS showing thunderstorms developing across central Vermont and New Hampshire Tuesday late afternoon. Storms may fire in northern New England starting in the early afternoon and continuing through the evening. Southern New England will see much more limited activity:
The threat of thunderstorms will likely come down to the extent of clearing that can occur in the afternoon in central New England. The northern tier of New England will have a tougher time clearing out the clouds, which would limit storm activity. If clearing occurs across the Champlain Valley, it would heighten the afternoon storm risk there. Southern New England will see more sun, but will also be further removed from the cold front, limiting afternoon activity. The sweet spot will likely end up between these areas.
Outside of the storm threat, it will be a warm day within the system's warm sector. Highs will reach into the 70s for most with low 80s possible across interior southern and central New England. A few cities may be able to check off their first 80° day of the season. Temperatures will be cooler across northern New Hampshire and into Maine as the warm front stalls out, leading to highs topping out in the 60s.
WEDNESDAY & THURSDAY
The previously mentioned cold front will push through the region Tuesday night and into Wednesday. As it does so, another disturbance will track to the south of New England during the day. These features will combine to create showers for Tuesday night through Wednesday.
Following recent trends, the low pressure passing to the south of New England has been trending farther and farther south. This keeps the greatest amount of moisture with the system to the south of New England. This should help prevent a total washout of a day, but scattered showers are likely throughout. Temperatures will be on the downward trend during this time, with highs 5-10° cooler than the previous day.
CMC showing scattered shower activity Wednesday afternoon, with the most widespread rain to the south:
Blocking downstream will prevent a timely exit of this system, so it will still be lingering nearby on Thursday, with shower chances continuing. How widespread showers are on Thursday will be determined by where exactly the system slows down and stalls out. The greatest chance for continued showers Thursday will be across southern and eastern New England.
Weather map for Thursday morning. Shower chances look to gradually diminish heading deeper into Thursday:
FRIDAY
Another trough will begin to approach on Friday while the previous one slowly drifts out to sea. This will bring continued shower chances. The day will likely end up featuring more clouds than sun. As of now, the day is looking to be mostly dry, but this will hinge on the timing of both the departing and approaching systems. Temperatures continue trending downward.
WEEKEND
That trough will extend into New England by the weekend. The exact timing of showers is uncertain at this time, but there will likely be a period of wet weather this weekend. As of now, Saturday is looking to be the wetter of the two days for most, but, again, timing really needs to be worked out.
Another thing to keep in mind is that guidance has been trending systems to the south as they approach, leading to a drying trend in the forecast as the event draws closer. Time will tell if this occurs this weekend, but it is certainly possible. It will be another weekend on the cool side, with 50s and 60s dominating.
Weather map for Saturday morning:
