Weather for New England and the Northeast

**Area Forecast Discussion**
National Weather Service Gray ME
222 PM EDT Tue Aug 25 2026

**WHAT HAS CHANGED**

No major changes were needed for this forecast package. Cloud cover was increased significantly for the rest of the afternoon because of widespread cumulus clouds.

**KEY MESSAGES**

1. A slow moving upper-level trough will trigger more isolated to scattered showers across the forecast area through the rest of today and into the evening, followed by a dry Wednesday under high pressure.

2. A series of fronts will bring widespread showers and possibly a few thunderstorms late Thursday and Friday.

3. Dry weather and lower humidity return for the weekend. Chances for showers return early next week.

**DISCUSSION**

**KEY MESSAGE 1 DESCRIPTION**

An upper-level trough, an elongated area of lower pressure higher in the atmosphere, is currently over the region. It has produced isolated to scattered showers, mainly across the higher terrain of New Hampshire and western Maine. Shower coverage should increase through the afternoon.

A few thunderstorms will also be possible because of weak atmospheric instability. SPC mesoanalysis, which is an analysis of current atmospheric conditions, indicates MLCAPE, a measure of available energy for thunderstorms, will peak around 250 to 500 J/kg. Wind shear is also expected to remain very weak. As a result, any isolated thunderstorms that develop should be fairly weak, although brief gusty winds will be possible beneath showers or thunderstorms.

Showers and thunderstorms should diminish quickly after sunset as daytime heating is lost. Valley fog will become more common overnight, with some marine fog also possible. Overnight lows will mainly be in the 50s.

High pressure moves in overnight and Wednesday as an upper-level ridge, an area of higher pressure in the atmosphere, moves into the region. This will bring dry conditions and warmer temperatures. Highs will mainly range from the low to mid 70s north, to the low to mid 80s across southern areas and along the coast.

**KEY MESSAGE 2 DESCRIPTION**

Clouds will increase and dewpoints will rise Thursday as a trough approaches the region. Most of the area should remain dry for much of the day, although forecast models indicate a chance for isolated to scattered showers as a warm front approaches. The best chance for showers will be across New Hampshire, while Maine may remain closer to departing high pressure.

High temperatures will reach the low 80s in most locations, with dewpoints in the mid 60s making it feel somewhat humid and sticky.

The first of two cold fronts will attempt to move through Thursday night. This will increase the chance for showers across the western half of the forecast area, while much of the eastern half and coast may remain at a 30 to 40 percent chance for precipitation as the front may weaken before moving farther east.

Friday morning could feature considerable fog and drizzle, with lingering moisture keeping dewpoints elevated. Cloud cover may also limit daytime heating and reduce the potential for stronger thunderstorms.

The RRFS, a high-resolution weather forecast model, currently suggests little more than scattered showers and thunderstorms. Longer-range rainfall probabilities also continue to decrease. The NBM, National Blend of Models, gives much of the area a 25 to 35 percent chance of receiving more than a half inch of rain, while the ECMWF and GFS model blends indicate only about a 10 to 15 percent chance.

Higher rainfall probabilities are expected in the mountains, where orographic lift, meaning air being forced upward by higher terrain, can increase rainfall rates. Outside of a stronger thunderstorm, most locations are likely to receive around a tenth to a quarter inch of precipitation.

This is not an especially helpful rainfall pattern from a drought perspective, but it continues a trend that has been persistent throughout the summer.

CSU machine learning guidance continues to show low probabilities for severe thunderstorms Friday. If little instability develops, the threat for severe weather should remain limited.

**KEY MESSAGE 3 DESCRIPTION**

The front is expected to clear the area by Saturday morning, and its timing will have an important effect on Friday night temperatures. If the front clears the mountains overnight, temperatures could fall into the upper 40s.

The foothills may fall into the low to mid 50s, while the coastal plain is less likely to completely clear and could remain in the upper 50s to low 60s, especially along the immediate coast.

Drier air will quickly move in Saturday as high pressure builds at the surface. This should produce a mostly sunny and precipitation-free weekend, with high temperatures in the mid 70s to low 80s and dewpoints in the 50s across much of the region.

Global forecast models indicate that at least one upper-level low will move through Quebec Sunday, making its closest approach Sunday night. This system may pull another front through the region early next week.

There remains considerable uncertainty among the global models regarding exactly how this system will develop and move. For now, the chance for precipitation from the NBM appears reasonable.