Weather for New England and the Northeast

**Area Forecast Discussion, National Weather Service Gray ME,
231 PM EDT Fri Aug 21 2026**

**What Has Changed**

No significant changes to the forecast were needed.

**Key Messages**

1. Mainly dry weather continues through tonight with cooler and unsettled weather this weekend.

2. A slow moving system will continue shower chances into early to mid week, with widespread measurable rainfall unlikely.

**Discussion**

**Key Message 1 Description**

Mostly dry conditions are expected to continue through tonight as high pressure sits overhead this afternoon. The high will then begin shifting to the northeast tonight as it gives way to multiple areas of low pressure that will move across Northern New England this weekend.

For tonight, skies should stay mainly clear away from the coast and southern New Hampshire, allowing temperatures to fall into the 50s south of the mountains, with some 40s to the north. More valley fog is likely along the Connecticut River. There is also a 20 percent chance of a few showers in southeast New Hampshire overnight.

The first area of low pressure approaches from the south Saturday morning. Skies will become mostly cloudy from south to north through the day as the system brings higher moisture into the region. Scattered showers are also expected, with dry periods in between. Forecast models continue to have difficulty agreeing on the timing, coverage and location of the showers.

Latest guidance shows broader upward motion over the Gulf of Maine, near the coast and across southeast New Hampshire during the morning and early afternoon. These areas will be the primary ones to watch for showers. The upward motion then spreads northward through the afternoon and evening, especially across western Maine, increasing the chance for showers. The 8 AM EDT NAMNest and HRRR model runs generally support this scenario.

Rainfall amounts are expected to remain light, although parts of western Maine could receive more than 0.25 inches of rain through Saturday evening.

More uncertainty exists Saturday night into Sunday morning. Some models favor a lull in the showers because of drying in the middle levels of the atmosphere while the lower levels remain nearly saturated. This would favor fog, possibly dense, along with drizzle. Other models show another area of low pressure developing, which would bring more showers and less fog. Because of this uncertainty, precipitation chances remain at 20 to 40 percent.

Sunday remains cloudy and dreary for most areas, with scattered showers possible at times during the morning. Another area of low pressure will track across Quebec and send a cold front eastward from the west. This will increase shower chances and could produce a storm or two during the afternoon and evening. Some showers may continue Sunday night, but they should gradually diminish south of the mountains from west to east behind the front.

**Key Message 2 Description**

A closed low, an area of low pressure cut off from the main upper level weather pattern, moving east of the Great Lakes will continue to pivot into southern Quebec Monday. Morning showers will move northeast across southern Maine, followed by thinning clouds across New Hampshire.

An embedded wave within the circulation of the low will lift north through the morning, while atmospheric instability increases through the middle of the afternoon. This could lead to an increase in shower and thunderstorm activity.

The atmosphere has some ingredients that could support thunderstorms, but there are also limitations. Wind shear, which is the change in wind speed and direction with height, will be around 50 knots in the lowest 6 kilometers of the atmosphere. This is enough wind shear to support organized thunderstorms and will overlap with marginal surface based instability early Monday.

The rate at which temperature decreases with height, known as lapse rates, should also support thunderstorms. However, increasing dry air higher in the atmosphere could limit storm development. For now, the forecast continues to include isolated to scattered showers and thunderstorms.

Tuesday may continue to be influenced by the closed low, with additional moisture producing more clouds and a chance of showers. Daytime heating will likely help trigger these showers, making them more dependent on daytime heating than on a passing front. Showers could become more widespread than currently forecast, depending on how the timing and influence of the closed low develops.

The low should finally lose its influence on New England by midweek as it moves northeast into the Canadian Maritimes. This should provide a break from the cloudy and dreary conditions, while temperatures remain seasonable.