A storm with tropical origins will bring the potential for flooding and damaging winds along the East coast of the United States spanning Saturday to Monday.
An area of showers and thunderstorms continued to gather along the coasts of Nicaragua and Honduras late this week.
"While the window for development is likely to close soon, this area of downpours may still organize into a tropical depression or storm into this weekend," according to AccuWeather Hurricane Expert Dan Kottlowski.
The storm will accelerate northward on a path that roughly parallels the southern Atlantic coast of the U.S. on Sunday, prior to racing northward across New England Sunday night and Monday.
Downpours to ramp up in northwestern Caribbean into this weekend
Showers and thunderstorms will gather over the northwestern part of the Caribbean through Saturday.
Areas from Nicaragua and Honduras to the Cayman Islands and Cuba are likely to bear the brunt of the downpours. These areas will also have the greatest risk of flash flooding and mudslides during the storm's early stage.
Interests surrounding the northwestern Caribbean should monitor this situation as tropical development may occur quickly.
Storm may trigger severe weather over South Florida on Saturday
As the storm continues to gather moisture and strength, locally severe thunderstorms may accompany torrential downpours in southeastern and central Florida and the northwestern Bahamas on Saturday and Saturday night.
People spending time outdoors should seek shelter at the first sign of threatening conditions. Small craft should consider remaining in port on Saturday as a precaution.
How strong the storm becomes will determine the severity of the weather conditions not only in Florida, but also farther north along the Atlantic coast.
Storm likely to hit northeastern US hard from Sunday to early Monday
Regardless of official tropical storm designation or not, this storm will pack a punch in terms of the consequences of heavy rainfall and gusty winds in a large part of the Northeast later this weekend into the start of the new week.
The greatest risk of urban flooding and damaging winds will extend from the Outer Banks of North Carolina to the Delmarva Peninsula, New Jersey, eastern Pennsylvania and New York state and much of New England.
This area is likely to receive between 2 and 6 inches of rain in 12 to 24 hours. Much of that rain may fall in six to 12 hours. Locally higher amounts are possible.
"Street flooding is likely, especially where leaves have fallen," according to AccuWeather Chief Meteorologist Elliot Abrams. "The leaves can block storm drains."
Sunday afternoon NFL games from FedEx Field to Lincoln Financial Field and MetLife Stadium may be played in torrential rain.
Winds, seas and surf will kick up as the storm races northward.
"Gusts close to hurricane force (74 mph) may occur along the coast of New England later Sunday night and Monday," Kottlowski said.
Winds this strong will bring down tree limbs, topple weakly rooted trees and lead to power outages.
"A brief storm surge could inundate low-lying coastal areas from Long Island to Connecticut, Rhode Island and Massachusetts," Abrams said.
The Monday morning rush hour may be a real mess from New York City to Albany, New York, and Boston. Expect both highway and airline delays.
Rain to hit, leave quickly as chilly air arrives from the west
Isolated incidents of urban flooding can occur farther west as well, but not from the storm on the Atlantic coast.
Only spotty showers and thunderstorms are forecast for the northwestern part of the Florida Peninsula, the Florida Panhandle, coastal Georgia and southeastern South Carolina on Saturday and Saturday night. This activity will be due to the approach of a push of much cooler air.
The leading edge of advancing chilly air will trigger downpours and spotty thunderstorms from the Ohio and Tennessee valleys on Saturday to the central and southern Appalachians and eastern Great Lakes on Sunday.
"As this cold air enters the departing storm, wet snowflakes may mix in over the higher elevations of West Virginia, Maryland, Pennsylvania and New York state by Monday," Abrams said.
The arrival of dry, chilly air will mark an abrupt end to the rain on Sunday in the Southeast states, Sunday night in much of the mid-Atlantic and Monday afternoon in New England.