Two storms will converge on the northeastern United States and bring the likelihood of flooding, damaging winds, travel disruptions and power outages from Sunday to Monday.
A storm with tropical origins will race northward and merge with a non-tropical storm from the Midwest later this weekend.
The result will be an intense storm with a period of heavy rain, strong winds and rough seas that slams the Northeast.
Travel conditions will deteriorate from south to north on Sunday and Sunday night. Airline delays will increase at the major hubs from Washington, D.C., to Baltimore, Philadelphia, New York City and Boston. The airline delays are likely to linger into Monday.
Monday morning rush hour from New York City to Boston and Albany, New York, is likely to be difficult to dangerous at times. Tree limbs may be down in wooded neighborhoods, and low-lying areas, such as underpasses, may be flooded. School delays are possible.
This area from eastern Pennsylvania and New Jersey to central and eastern New York state to New Hampshire has the greatest potential for flash and urban flooding. This zone is likely to receive between 2 and 6 inches of rain in 12 to 36 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.
Strong winds will be a problem. The winds will be strong enough to knock down trees, cause minor property damage and power outages.
"The strongest winds, southeasterly gusts close to hurricane force (74 mph), may occur along the coast and mountains of New England as the storm moves up and strengthens and Sunday night into Monday," Kottlowski said.
"Strong gusts from the west will develop as the storm strengthens and moves away, especially over Pennsylvania, Virginia and Maryland on Sunday night and Monday," according to AccuWeather Senior Meteorologist Dave Dombek.
In addition to flooding from heavy rain and power outages from high winds, coastal flooding is also anticipated.
"A brief storm surge could inundate low-lying coastal areas from Long Island to Connecticut, Rhode Island and Massachusetts," Abrams said.
The high tide cycle from late Sunday night to early Monday morning will be the most troublesome. Water levels may be as much as 2-4 feet above normal.
Tail end of storm may bring snow to higher elevations
"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.
Fast movement of the storm and the arrival of cold air too late on the scene will prevent a major high-elevation snowstorm from unfolding.
Only if the storm's forward progress stalls would accumulating snow fall on lower elevation areas where most people live.
The arrival of dry, chilly air will mark an abrupt end to the rain on Sunday evening in the central Appalachians, Sunday night in much of the mid-Atlantic and Monday afternoon in New England.