A potential tropical depression or storm is likely to impact parts of the western Caribbean to the immediate Atlantic coast of the United States prior to the end of October.
A budding tropical disturbance, currently near the coast of Nicaragua, may become the Atlantic's next tropical depression or tropical storm in the coming days. The next name on the list of tropical storms for 2017 is Philippe.
In the short term, conditions are favorable for slow development with the disturbance over warm waters and relatively light winds aloft, according to AccuWeather Hurricane Expert Dan Kottlowski.
Ultimately, how strong the tropical feature becomes will determine the amount of rain and wind that occurs along its path. However, even if the feature fails to become a tropical storm, enough rain is likely to fall to cause flash and urban flooding.
"The disturbance is likely to drift across the northwestern Caribbean into Friday, then across the Florida Straits and part of South Florida on Saturday," Kottlowski said.
"The storm is most likely to take a path parallel to the Atlantic coast of the U.S. on Sunday and Sunday night."
Increasing winds aloft and the approach of a non-tropical storm will cause the tropical feature and its rain to accelerate northward. By the time it reaches New York state and New England, it may be moving along at a pace close to 40 mph.
While its fast movement may limit the storm's tropical intensity and duration of the rain, interaction with the non-tropical storm will enhance the rainfall rate and may still cause strong wind gusts.
What is the timeline for the potential tropical system and its impacts?
As the system brews and crawls over the northwestern Caribbean, adjacent areas from Central America to southeastern Mexico, Cuba and Jamaica will be at risk for flooding downpours, locally gusty thunderstorms, mudslides and dangerous surf this week.
As the tropical system accelerates northward this weekend, the risk of flooding downpours and gusty thunderstorms will focus on Florida and the Bahamas on Saturday.
Heavy rain, strong winds and the risk of flash and urban flooding will race northward from the Carolinas to the mid-Atlantic and New England on Sunday.
In addition to the flood risk from leaves blocking storm drains, wind gusts may be strong enough to break tree limbs and cause sporadic power outages.
The fast pace of the storm in the Northeast should limit the duration of any coastal flooding and beach erosion to several hours.
The rain and strong wind may leave areas from Washington, D.C. to Philadelphia and New York City by Monday's morning rush hour. However, if the system is a bit slower, then difficult travel and storm conditions will start the week in these areas.
At this time, at least the first part of Monday looks to be stormy in New England. Heavy rain and gusty winds are likely in Quebec, New Brunswick and Nova Scotia on Monday.
Rapid strengthening could lead to a different track
There is a chance the tropical feature quickly becomes a hurricane. Rapid development of this sort may result in a more northeasterly path toward central Cuba on Friday, then the central Bahamas on Saturday and Bermuda by early next week.
Because of the potential for more of an easterly track and a stronger storm, people from the central Caribbean islands to Bermuda should monitor the situation.