Subtropical Storm Josephine Accelerating Away from Southern New England
After hanging around south of New England and east of the mid-Atlantic coast for days, the offshore storm has started to accelerate to the NE ahead of a rigorous upper trough heading toward the Canadian Maritimes. It will turn more toward the east tonight and pass south of Nova Scotia tonight into Friday and south of Newfoundland Friday night and Saturday on its way to the open North Atlantic.
Although extratropical in origin, the storm acquired enough subtropical characteristics as it lingered over the Gulf Stream Wednesday afternoon for the National Hurricane to name it Subtropical Storm Josephine. The storm had become detached from a frontal system and developed convection over the warm waters of the Gulf Stream. Josephine, however, will undergo a transition back to an extratropical (or in this case post-tropical) storm tonight as it interacts with the upper trough heading to the Canadian Maritimes. Even though a transition to extratropical status is expected, it may actually strengthen further as it interacts with the upper trough to the point where it develops a band of hurricane force winds. Thus, this storm will continue to pose a hazard to offshore marine operations over the northwest Atlantic for at least another couple of days.
This storm appears to have produced wind gusts between 45 and 55 mph over the outer Cape and Islands. Have noted seas reaching 20 feet over Nantucket Shoals and even as high as 10 feet in Massachusetts Bay. Fortunately, the astronomical high tides have been low and precluded a coastal flood risk over the Cape and Islands even with a 1.5 to 2-foot storm surge. Nevertheless, the pounding surf over multiple tide cycles may have caused pockets of beach erosion across exposed shorelines along the outer Cape, Nantucket, and Martha’s Vineyard. Bands of rain did reach the Cape and Islands last night but have since pulled away.
Looking ahead, the wind over the Cape and Islands will gradually diminish tonight and Friday. Sunshine and moderating daytime temperatures are expected over the weekend into at least the first part of next week across southern New England. The nights will be cool, however, with areas of frost likely over many interior locations.
Tropics
Tropical Storm Vance in the eastern Pacific is expected to intensify into a major hurricane this weekend off the Mexico west coast. Vance may turn more to the north by late in the weekend and could become a serious threat to the west central Mexican coast early to the middle of next week.
Next Message
The next message will likely be the weekly significant weather outlook scheduled for Monday October 26.
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Message issued October 22, 2026 by:
Bob Thompson
Retired National Weather Service Meteorologist
Blue Hill Observatory and Science Center Advisory Council member
