Weather for New England and the Northeast

Area Forecast Discussion, National Weather Service Boston/Norton MA

Date and Time: 242 PM EDT Wednesday, October 21, 2026

What Has Changed

Adjustments have been made to marine headlines, including extending some advisories and upgrading certain Gale Watches to Gale Warnings. Otherwise, there have been no significant changes to the forecast.

Key Messages

Key Message 1: An offshore storm will continue to produce stronger northerly wind gusts through Friday morning. Mainly light rain or sprinkles are possible overnight tonight into early Thursday across southeastern coastal New England, tapering off Thursday afternoon.

Key Message 2: A prolonged stretch of dry weather is expected from Friday through Wednesday. Temperatures will be cooler Friday, gradually moderating through Monday before turning cooler again around the middle of next week.

Discussion

Offshore Storm, Winds, and Rain Chances

The forecast for southern New England remains largely unchanged through Friday as a distant low pressure system slowly moves northward well offshore, east of the mouth of the Chesapeake Bay. As of Wednesday afternoon, the storm is primarily bringing increased cloud cover to southeastern New England, along with stronger northeast winds.

Most mainland locations are experiencing gusts of 20 to 25 mph, while Cape Cod and the Islands are seeing stronger gusts of 35 to 45 mph. A noticeable difference in cloud cover exists north and west of Interstate 95, where a broad area of high pressure is bringing cooler, drier air and generally clearer conditions.

Radar imagery Wednesday afternoon shows the western edge of the offshore storm rain shield moving into the far southeastern ocean waters. Forecast guidance suggests that this area of rain will gradually spread northwestward toward the Islands, the south coast, and Cape Cod tonight.

However, the incoming rain will encounter increasingly dry air, with dew points in the 30s. This dry air will limit rainfall, and any precipitation reaching the south coast and Cape Cod should be very light. In some locations, the sprinkles may struggle to reach the ground. Nantucket and Martha Vineyard have the best chance of seeing steadier light rain overnight tonight into early Thursday morning.

As the offshore storm moves northeast on Thursday, rain chances will decrease and cloud cover should gradually diminish across southeastern New England. Dry weather is expected for the remainder of Thursday and into Friday as another area of high pressure builds southward from northern Canada.

Wind and Marine Conditions

The main impact across southern New England will continue to be the stronger northeast to northerly winds. Cape Cod and the Islands can expect gusts of 35 to 45 mph through Thursday around midday. Winds should gradually ease Thursday night into Friday, with gusts generally decreasing to 20 to 35 mph.

Ocean conditions will remain rough, with seas continuing to build. The greatest impacts will be felt by boaters and others spending time on the water. Mariners should pay close attention to the latest marine warnings and advisories.

Temperatures Tonight Through Friday

Differences in cloud cover and onshore winds will continue to produce a wide range of temperatures across the region. As the offshore storm moves away, it will draw increasingly cooler air into southern New England Thursday night.

For areas along and northwest of Interstate 95, clearing skies and lighter winds will allow temperatures to fall more sharply at night while permitting warmer afternoons when sunshine is more plentiful.

Tonight, temperatures should fall into the upper 30s to middle 40s across northwestern Massachusetts and areas extending toward Interstate 95. Thursday afternoon highs should reach the lower to middle 60s in these locations.

A colder air mass will arrive Thursday night, bringing temperatures down to around 28 to 34 degrees across the same inland areas. Some locations could experience a light freeze.

Southeastern coastal areas will experience a smaller temperature range because of persistent cloud cover and stronger northerly winds. Highs will generally remain in the middle to upper 50s, while overnight lows will be milder, mainly in the middle 40s to lower 50s.

Dry Weather and Temperature Trends Friday Through Wednesday

High pressure will dominate the weather pattern into early next week, bringing an extended period of dry weather. Temperatures will turn cooler Friday as high pressure initially builds in from eastern Canada, then gradually moderate through Monday.

The forecast becomes less certain Tuesday and Wednesday as a frontal boundary develops between two areas of high pressure. One will be positioned over the central Appalachian region by Monday, while another will be located over Manitoba and Saskatchewan in Canada.

The eventual movement of the front will depend largely on which area of high pressure becomes stronger. Current thinking favors the Canadian high pressure system, which could push the front across southern New England sometime between Monday night and Wednesday.

The exact timing and how far south the front travels remain uncertain and will be refined in future forecasts.

Rain Chances Next Week

At this time, the approaching front appears to have limited moisture available. The most likely outcome is a period of increased cloud cover and cooler temperatures around the middle of next week.

However, only a small increase in available moisture would be needed to introduce a chance of showers into the forecast. For now, dry conditions remain the most likely outcome, but rain chances could change as the timing and strength of the front become clearer.