Weekly Significant Weather Outlook
The main weather development of interest for this week will be a large and slow-moving offshore storm to our south. This robust storm will likely remain centered well south of New England but close enough to bring gale force winds to the coastal waters about the Cape and Islands (Nantucket, Martha’s Vineyard, and Block Island). The surface pressure gradient between high pressure just north of New England and the low pressure centered to the south will result in strong winds extending relatively far north from the storm center. Seas will likely build to at least 12 to 15 feet off the Cape and Islands. Fortunately, the astronomical high tides are relatively low this week and so coastal flooding is unlikely. Nevertheless, the persistent wave action may result in areas of beach erosion along exposed Cape Cod, Nantucket, and Martha’s Vineyard shorelines. There’s some uncertainty as to whether or not the northern extent of the rain shield makes it to the Cape and Islands mid-week.
Tropics
The National Hurricane Center is monitoring this offshore low center development well east of the mid-Atlantic coast, since it may acquire for a time subtropical characteristics. This may occur if the low center lingers long enough over the Gulf Stream and becomes detached from any frontal structure. Even if this should happen, the system would be expected to maintain the appearance of an offshore nor’easter.
Next Message
The next message will probably be the weekly significant weather outlook scheduled for Monday October 26. Additional messages could be prompted, however, if the low center to our south should drift far enough north to have a higher impact on southern New England.
About this Blog and Disclaimer
The National Weather Service monitors the weather 24/7 and updates forecasts, watches, and warnings as necessary. For most of southern New England, refer to your local Weather Forecast Office for the latest forecast/warning information at weather.gov/box. For information from other Weather Forecast Offices, go to weather.gov and click on the location of interest on the map.
The frequency of this blog will depend upon the nature of the weather threat and availability of the author. Thus, for the latest information on weather forecasts and warnings, refer to the National Weather Service, which monitors and forecasts the weather 24/7.
Blue Hill Observatory and Science Center (BHOSC)
The BHOSC maintains a continuous daily observation record that dates from February 1, 1885 without interruption and provides educational information on weather and climate to area students and the community at large. Your support of BHOSC is much appreciated and enables this nonprofit organization to maintain the long-term climate record at the Blue Hill Observatory (longest continuous record in North America) and provide valuable educational resources on weather and climate via outreach to schools, site visits/tours, webinars, and conferences. For more information on the Blue Hill Observatory and Science Center, explore bluehill.org.
Message issued October 19, 2026 by:
Bob Thompson
Retired National Weather Service Meteorologist
Blue Hill Observatory and Science Center Advisory Council member
