The National Weather Service had 37 active flood alerts posted Sunday, down from 40 a day earlier, but the geographic center of the threat has swung sharply eastward, with Kansas dropping off the list entirely while New York, New Jersey, Pennsylvania and Massachusetts appear for the first time this week.
The most significant new development is a flash flood warning covering the entire New York City metro area — Manhattan, the Bronx, Brooklyn, Staten Island and Queens — along with both Nassau and Suffolk Counties on Long Island, Westchester, Rockland, Orange and Putnam Counties. Neighboring New Jersey has warnings active in Passaic, Hudson, Bergen, Essex and Union Counties. In Connecticut, the Weather Service has flagged Litchfield County, along with Dutchess and Ulster Counties in eastern New York, for flash flooding from late Sunday night through Tuesday morning, warning that excessive runoff could flood rivers, creeks and poor drainage areas.
Central Pennsylvania has also emerged as a hot spot, with warnings stretched across a broad swath of counties including Centre, Huntingdon, Mifflin, Juniata, Franklin, Clinton, Lycoming, Union, Snyder, Montour, Northumberland, Columbia, Perry, Dauphin, Schuylkill, Lebanon, Cumberland, Adams, York and Lancaster.
Meanwhile, the Midwest river flooding that dominated recent days continues, though the Weather Service says conditions there are improving. In Iowa, minor flooding is occurring on the South Skunk River near Ames, affecting Story and Polk Counties, and at Colfax, affecting Marion, Jasper and Polk Counties; Black Hawk Creek at Hudson is also under a warning affecting Black Hawk County. Kentucky and Illinois, which saw new warnings issued Saturday, remain on the list, as do Louisiana, Missouri and Wisconsin.
In the Pacific, Guam, Rota, Tinian and Saipan remain under a flash flood watch through late Tuesday night as shower and thunderstorm activity continues before conditions are expected to deteriorate further, according to the Weather Service.
The shift from 40 to 37 alerts suggests the Midwest flood threat is gradually resolving even as a separate storm system pushes heavy rain into the Northeast corridor. The Weather Service is urging residents from central Pennsylvania through the lower Hudson Valley and greater New York City to monitor forecasts closely and avoid driving through flooded roadways, noting that flash flooding can develop quickly in urban areas and poor-drainage locations. Additional warnings are possible as the rain moves through the region over the next 24 to 48 hours.