Weather for New England and the Northeast

**Area Forecast Discussion, National Weather Service Gray ME, 235 PM EDT Thu Aug 6 2026**

**What Has Changed**

A Heat Advisory has been issued for portions of southeastern New Hampshire, southern Maine, and the MidCoast of Maine for Friday.

**Key Messages**

1. Hot and humid conditions continue into Friday. There will be chances for showers and isolated thunderstorms through this evening, mainly across New Hampshire.

2. A mid level disturbance, a pocket of unsettled weather several miles above the ground, will bring a more robust chance for showers and thunderstorms Saturday.

3. Looking ahead to next week, the greatest threat for shower and thunderstorm activity will be Tuesday, with a gradual cooling trend expected through the week.

**Discussion**

**Key Message 1 Description**

Latest satellite and radar imagery shows fair weather clouds continuing to develop across the region, while scattered showers and thunderstorms remain to the west across upstate New York. High pressure several miles above the ground, known as deep layer ridging, is expected to remain strongest over eastern Maine, helping limit the overall thunderstorm coverage across much of the forecast area.

Even so, the atmosphere over New Hampshire is becoming increasingly unstable this evening. Forecast instability values, referred to as surface based CAPE, are expected to exceed 2000 J/kg, indicating the atmosphere will have enough energy to support thunderstorm development. This could allow a few storms moving east from New York to survive into New Hampshire.

Any storm that remains organized could produce gusty winds and torrential rainfall because the atmosphere contains abundant moisture, measured by a value known as precipitable water. Despite this, the overall threat for severe thunderstorms and flash flooding remains low.

Thunderstorm activity should gradually diminish after sunset as daytime heating fades. Tonight will remain warm and humid, with overnight lows in the upper 60s to low 70s. Patchy fog may develop across much of the area, especially in river valleys and near the coastline.

Humidity will spread farther north on Friday as dew points climb into the upper 60s and low 70s across much of the region. Combined with afternoon temperatures reaching the upper 80s to low 90s, heat index values will climb into the middle 90s. A Heat Advisory has been issued for southeastern New Hampshire and the coastal plain of Maine where confidence is highest that heat index values will exceed 95 degrees.

Although the atmosphere will once again become unstable enough for thunderstorms, there will be little large scale lift to trigger storm development. As a result, only isolated thunderstorms are expected, with many locations remaining mostly sunny. Friday night will stay warm and humid with overnight lows in the upper 60s.

**Key Message 2 Description**

A shortwave, a small disturbance moving through the atmosphere several miles above the ground, will move through the warm southwest flow on Saturday and bring a much better chance for showers and thunderstorms.

Forecast winds several miles above the ground will strengthen to around 30 knots while atmospheric moisture remains high, with precipitable water values exceeding 1.75 inches. Forecast guidance is in good agreement that measurable precipitation will occur, but there is still uncertainty regarding how much of the day will be wet because there is no well defined surface front to organize thunderstorm development.

Some forecast models suggest thunderstorms could develop early in the day, limiting afternoon instability and reducing the severe weather threat. However, this would increase the potential for a wetter day with localized downpours and isolated flooding.

If morning storm activity is limited, greater daytime heating would allow additional instability to develop, creating a marginal risk for severe thunderstorms. Machine learning forecast guidance also suggests some potential for damaging wind gusts, supported by stronger winds higher in the atmosphere.

For now, precipitation chances remain likely to categorical across much of the northern two thirds of the forecast area where upper level winds are strongest, while southern areas carry lower chances. Despite the continued muggy conditions, increased cloud cover should keep afternoon temperatures somewhat cooler than Friday, with highs generally in the 80s. Heat index values may still reach around 90 degrees south of the foothills.

**Key Message 3 Description**

Next week will generally feature west to northwest winds several miles above the ground. Forecast guidance continues to show another round of precipitation Tuesday into Tuesday night as another fast moving upper level disturbance moves through the region.

Although there are still differences in the exact track and timing, partly because thunderstorms themselves can alter local weather conditions, a cold front appears likely to move through during this period. There could be some risk for severe thunderstorms because of stronger winds in the middle levels of the atmosphere, although confidence remains limited since storm timing will determine how much instability develops.

Forecast precipitation chances remain high for Tuesday into Tuesday night, and this period will continue to be monitored for the potential of severe weather or localized flash flooding. At this time, a widespread significant event does not appear likely.

Conditions become quieter Wednesday before another stronger cold front approaches late next week. This system has the potential to bring a more noticeable cool down by next weekend.

From Tuesday through Thursday, temperatures should generally remain near normal for early August, with afternoon highs ranging from the 70s in northern areas to the 80s farther south.