Weather for New England and the Northeast

**Area Forecast Discussion, National Weather Service Boston/Norton MA
239 PM EDT Sat Aug 29 2026**

**WHAT HAS CHANGED**

No significant changes.

**KEY MESSAGES**

More summer-like conditions return tomorrow. Rain chances return late Sunday.

Backdoor cold frontal boundary Monday brings onshore flow, decreased cloud cover and cooling afternoon temperatures.

Unsettled Tuesday through Thursday with several opportunities for showers and thunderstorms, with a chance for some to become strong in western MA and CT. Timing which days may have better storm chances is still uncertain.

**DISCUSSION**

**KEY MESSAGE 1, More summer-like conditions return tomorrow. Rain chances return late Sunday.**

Dry and sunny conditions with some daytime cloud development continue through the rest of today. Dew points remain in the 40s and 50s across the region through tonight, with lows in the 50s and low 60s.

Temperatures around 925 millibars, roughly 2,500 to 3,000 feet above the ground, remain generally around 59 degrees today before increasing slightly to around 64 to 68 degrees tomorrow. High pressure begins shifting east, allowing southwest winds to develop. Highs tomorrow return to the low to mid 80s, along with slightly increased humidity.

Latest guidance continues to indicate a weak area of low pressure moving close to the region Sunday night, with the greatest chance for rain generally south of Interstate 90. Showers remain possible across all of southern New England beginning during the late evening hours.

There is a low chance for some embedded thunder, meaning thunderstorms developing within areas of otherwise scattered showers, but this potential is generally limited to the south coast and southern waters. A widespread washout is not expected. Confidence is higher that showery conditions will continue overnight Sunday toward the south coast before clearing Monday morning.

**KEY MESSAGE 2, Backdoor cold frontal boundary Monday brings onshore flow, decreased cloud cover and cooling afternoon temperatures.**

Monday looks to be the least active day of the upcoming workweek, although a backdoor cool front will slip southwest from coastal New Hampshire and Maine early in the day. The front will continue southwest and tend to stall somewhere near southwest Connecticut or southern New York late in the day.

Considerable cloudiness early Monday should give way to increasing northeast winds, decreasing cloud cover and temperatures that either hold steady or slowly cool during the afternoon.

Temperatures should reach the low 80s in western Massachusetts and Connecticut. Across eastern Massachusetts and Rhode Island, midday temperatures should reach the mid to upper 70s before cooling into the low to mid 70s by sundown.

Cloud cover increases again Monday night, but conditions should remain dry for the most part. Rain chances increase toward the pre-dawn hours Tuesday.

**KEY MESSAGE 3, Unsettled Tuesday through Thursday with several opportunities for showers and thunderstorms, with a chance for some to become strong in western MA and CT. Timing which days may have better storm chances is still uncertain.**

Tuesday through Thursday look more active and unsettled. The backdoor frontal boundary is expected to stall from southwest to northeast through New York State. At the same time, the northeastern edge of a substantial area of high pressure and heat centered over the Ohio Valley Tuesday may build into the northern Mid-Atlantic and perhaps a small portion of southern New England.

This setup places southern New England between a more stable and seasonable air mass to the northeast and a warm to hot, humid and potentially unstable air mass to the southwest.

Above the stalled surface boundary, strong northwest winds several miles above the ground will develop. For example, winds near 300 millibars, roughly 30,000 feet above the ground, may approach 100 knots, or about 115 mph. This strong upper-level flow can help move smaller disturbances, known as shortwaves, southeastward along the stalled front. These disturbances can provide additional lift and help trigger showers and thunderstorms.

Several opportunities for showers and thunderstorms appear likely during this period, but the details remain uncertain. The main factors are the exact position and movement of the frontal boundary, whether southern New England can tap into the more unstable air to the southwest, and the timing of the smaller disturbances moving through the strong upper-level winds.

Machine-learning guidance from the Global Ensemble Forecast System, or GEFS, and Colorado State University shows some potential for severe weather across western and southwestern areas during this period. The Storm Prediction Center, or SPC, currently highlights a small portion of western Hampden County and western and central Hartford County with a 15 percent probability of severe weather for Wednesday. This is an unusually early indication of severe weather potential for a Day 5 forecast.

There is some skepticism that southern New England will become firmly established within the more unstable air to the southwest. The better chance of tapping into that air would likely be south and west of Worcester. This will need to be monitored more closely as higher-resolution, shorter-range models become available.

Rain chances are relatively high for a medium-range forecast, generally in the 30 to 60 percent range from Tuesday through Thursday.

Temperatures are expected to remain mainly in the 70s to low 80s Tuesday through Thursday, with rather mild overnight lows in the mid 60s. For perspective, typical overnight low temperatures at this time of year are in the upper 50s to around 60 degrees.