Unsettled Saturday (for some) Before a Stretch of Summery Weather in New England

A frontal system will continue crossing to the north of New England through the day today. This system will lift a warm front into New England this morning and afternoon before a cold front moves through in the evening and overnight tonight. The biggest question remains just how far north that warm front can push before the cold front moves through as this will determine just how mild it can get this afternoon and evening.

A period of steadier rain will likely fall on the north and east side of the warm front, where conditions remain cooler and forcing for showers and possibly downpours will be greatest. Trends over the past 24 hours have continued to push the warmer air farther north, which likewise pushes the heaviest rain farther north. The slug of steadier rain looks to be focused over much of Maine. A widespread half inch to inch of rain is possible across Maine with totals lowering moving south and west in New England.

Below: HRRR showing potential weather early this afternoon:

Areas near and south of the warm front will see much more scattered shower activity, milder temperatures and higher instability (with regards to potential thunderstorm development as the cold front moves through). These areas will get into the warm sector of the system. While there remains a spread in just how far north this front makes it, southern New England will likely see it push north by Saturday afternoon.

Areas south and west of the boundary could see breaks in the clouds and temperatures shoot well into the 70s toward the low 80s. Areas farther north and east will remain in the 60s to low 70s while much of Maine may struggle to climb out of the 50s. Overall, there's big bust potential with Saturday's temperatures, especially if the front gets hung up farther south than anticipated, in which cooler temperatures would remain over southern and central New England.

Below: NAM showing potential temperatures late this afternoon:

The system’s cold front will push through New England later in the day, likely sparking a line of scattered storms and showers in the late afternoon and evening, moving west to east. Areas that get well into the warm sector today will have the best chance at seeing thunderstorms, and possibly strong storms. Conditions will be marginally unstable and there will be enough shear and moisture for stronger storms.

The issue will be the weak forcing until the cold front arrives, which won't be until the evening in western New England. Storms will likely be weakening as they enter into western New England and will continue to weaken as they push farther east through the evening and into the first part of the night. Still, a few storms may contain strong winds, especially west of the Connecticut River.

Below: HRRR showing potential weather this evening:

Sunday will be a quiet and comfortable summer day. The cold front will shift offshore, allowing a drier air mass to move in, setting up clearing skies after what will likely be a cloudy start. Despite the cold front, a warmer air mass will move into New England with a change to a warm westerly flow. The cold front's drier air mass will help keep dew points and humidity in check.

New England's next system will likely arrive on Tuesday in the form of another frontal system. A warm front will likely lift across New England in the morning followed by a cold front in the afternoon/evening. This warm front will usher in dew points into the 70s, making for a very humid day.

These setups often see a round of showers and storms in the morning with the warm front, followed by isolated storms in the afternoon before a line of more numerous storms moves through along the cold front later in the day. Being several days out, specific timing in regards to how this one will play out remains to be seen, but the above description offers a very general look at how these summer systems tend to play out.

Below: Current weather map for Tuesday morning:

As for temperatures, a Bermuda high looks to build back, bringing a warming trend with widespread 80s to low 90s and higher humidity back into the picture. Much of next week looks to feature persistent summer temperatures with humidity. The typical warm valleys of New England could see a heat wave, which is officially three straight days with a high temperature of at least 90°. The level of heat will not come close to the heat seen earlier this week.