Rainy Saturday, Cooler Sunday in Store for New England

An area of low pressure will cross northern New England through the day today, bringing plenty of rain with it. The most widespread steady rain will come along a frontal boundary ahead of the actual low center this morning and into the early afternoon. A majority of rainfall will come with this band in the morning hours. This system will have plenty of moisture to work with as it has a connection to high Gulf moisture. This will allow for a period of moderate rainfall with the potential for heavier downpours embedded within it.

As the center of the low pressure system crosses northern New England, a dry slot will likely develop from west to east this afternoon. This will come as the core of the low-level jet (which is transporting the high moisture content from the south) will move offshore. The dry slot is unlikely to be totally dry, but rain will likely become more scattered in nature from west to east this afternoon and evening.

Below: FV3 showing potential weather later this afternoon:

The system's cold front will slide through New England this afternoon and evening, providing the basis for another round of scattered showers and potentially some thunderstorms. Modest instability will develop within the warm sector today, likely enough for some pop-up thunderstorms to develop. The main issue for storms will be the lack of sunshine. Breaks of sun will be needed for instability to build enough for scattered storms to develop along the cold front.

The best chance for some breaks of sun this afternoon within the dry slot will be across the western half of New England. Overall, the level of potential sunshine remains the biggest wild card this afternoon. Guidance is pessimistic about clouds breaking at all, but a few peeks of sun will be possible should enough breaks in the showers develop. Either way, strong to severe storms are likely to remain to the south of New England, where better conditions for storm development will exist along the front.

Below: Storm Prediction Center thunderstorm outlook today:

By the time the cold front passes through New England Saturday night, a widespread half inch to inch and a half of rain will likely have fallen. The day may not be a total washout from sunrise to sunset, but there will be more wet hours than dry hours today. A coastal front may set up, which could enhance rainfall totals along the coastal plain. The best chance for over an inch of rain will be along Maine's coast, particularly the Midcoast and points east. A secondary jackpot zone over interior western New England is also likely.

The system will be slow to depart on Sunday. It will likely linger across the eastern Maine coastline for much of the day. This will allow enough moisture and cyclonic flow to hang around to allow for a mainly cloudy day region-wide. The system will likely cycle scattered showers into the region as well. Sunday showers are most likely across northern New England, but a spot shower could occur anywhere.

The mountains will likely see a switch to snow with colder air filtering in behind the cold front. While it certainly won't be cold enough for snow outside of mountains Sunday, it will be chillier than it has been for all of New England. Highs will likely top out in the upper 30s to mid 40s north and mid 40s to low 50s south.

Right on cue, this beautiful stretch of weather we've been in will return after this weekend. Warm high pressure builds in for Monday and Tuesday with temperatures in the 60s north and 70s south with plentiful sunshine. New England's next precipitation chance will come around midweek next week with another frontal system. Depending on where the system passes relative to New England and the time of day, it could result in the first real afternoon thunderstorm day of the season. Later next week trends cooler after the passage of a cold front.