Weather for New England and the Northeast

**Area Forecast Discussion, National Weather Service Boston/Norton MA**
**257 AM EDT Mon Jul 20 2026**

**What Has Changed**

Gale Watch issued for Tuesday afternoon through Wednesday early evening.

**Key Messages**

* Seasonable summer weather today with temperatures in the 70s to mid 80s, with sea breezes near the coasts.

* Active weather Tuesday and Wednesday. Potential for hazardous marine conditions, high surf, soaking downpours and a limited risk for severe weather.

* Drying out late week with a return to more seasonable temperatures and lower humidity levels into next weekend.

**Discussion**

**Key Message 1, Seasonable summer weather today with temperatures in the 70s to mid 80s, with sea breezes near the coasts**

Another excellent summer day is expected to begin the workweek. High pressure centered near Cleveland, Ohio will build southward, bringing a light west southwest to southwest breeze later today. Local sea breezes are still expected to develop along the coastline. Sunshine will allow afternoon temperatures to reach the upper 70s to the mid 80s, with cooler conditions near the coast where the sea breezes develop.

Skies remain mostly clear tonight, although increasing moisture moving into the region may allow for some patchy mist or low clouds across interior southern New England. Any impacts should be minimal.

**Key Message 2, Active weather Tuesday and Wednesday. Potential for hazardous marine conditions, high surf, soaking downpours and a limited risk for severe weather**

As high pressure moves offshore, a cold front approaching from the Great Lakes will bring a much more active weather pattern. Strong winds several thousand feet above the ground will transport very humid air into southern New England. Meteorologists refer to this as **moisture advection**, meaning a large amount of moisture is being carried into the region ahead of the approaching front. Atmospheric moisture values will become unusually high, creating favorable conditions for heavy rainfall.

The primary concerns, in order of confidence, are hazardous marine conditions and rough surf, periods of heavy rainfall, and a lower risk for strong to severe thunderstorms.

A Gale Watch has been issued for most coastal waters from Tuesday afternoon through Wednesday evening. Forecast guidance continues to indicate a good chance of wind gusts reaching gale force, especially across the eastern offshore waters. Winds may become strong enough to create dangerous boating conditions, with seas building as high as 12 feet. Although much of the wave action will be generated by the strong southerly winds, dangerous surf and an increased risk of rip currents may develop along exposed beaches. Gale Watches are relatively uncommon during the summer, highlighting the potential seriousness of this event.

Showers and thunderstorms will become more numerous Tuesday afternoon, with the greatest coverage expected Tuesday night into Wednesday morning. Strong winds in the middle and upper atmosphere, along with increasing humidity, will provide favorable conditions for thunderstorm development. While the greatest severe weather threat is expected west of southern New England, a few stronger storms could still develop locally.

Damaging straight line winds and even a brief tornado cannot be ruled out if enough atmospheric instability develops. Wednesday may offer another opportunity for stronger storms as daytime heating increases after the front begins moving offshore.

Rainfall is expected to be heaviest across southern Connecticut, the south coast, Cape Cod, and the Islands. There is a moderate chance that these locations receive more than 1 inch of precipitation, while lower amounts are expected farther inland.
Although sandy soils across Cape Cod can absorb water efficiently, repeated heavy downpours could still lead to localized flooding, especially in urban areas across Rhode Island and southeastern Massachusetts if storms repeatedly move over the same locations.

**Key Message 3, Drying out late week with a return to more seasonable temperatures and lower humidity levels into next weekend**

The cold front is expected to stall well offshore by Thursday while high pressure builds eastward from the Great Lakes.

Forecast temperatures in the atmosphere will be cooler than average for late July, but with strong July sunshine, afternoon temperatures should still remain seasonable. Expect dry weather, comfortable humidity, and pleasant summer conditions from late this week through much of the weekend.

Humidity will begin increasing again by Sunday as winds gradually shift back from the south.