(CNN) – A mass of moisture stretching from the eastern Pacific to the US East Coast has resulted in extreme rainfall in the northeast, while some places are already experiencing flooding.
More than 50 million people are under flood warnings as of the end of this Tuesday in several major cities such as Washington, Philadelphia, New York, Boston and Providence, Rhode Island.
As of Tuesday morning, millions of people in parts of Connecticut and Pennsylvania were facing flash flood warnings. This means that some places were already flooded.
“Flash flooding continues or is expected to begin soon,” the National Weather Service reported, particularly in central Middlesex and Haven counties.
The Weather Prediction Center said West Virginia and the Central Appalachians are also at risk.
a storm system

Areas of the United States that are subject to flood warnings.
The heavy rain is related to the same storm system that flooded parts of Georgia on Sunday, as well as extreme rain in the Appalachians and Northeast on Monday.
This storm system will form a low pressure area over the mid-Atlantic coast from Tuesday, bringing heavy rain in the afternoon.
“This will make the region from northern Delaware to southeast New York to southern New England with the highest rainfall,” the forecast center said.
“Heavy rainfall with relatively slow-moving thunderstorms may result in scattered instances of flash flooding from southern New England to the Delmarva Peninsula, including major cities on I-95 from Boston to Philadelphia,” officials said.
The region has already recorded 2.5 to 7.6 cm of rain. The National Weather Service said flooding is a concern in some places, with additional 1 to 3 inches of rain expected.