Bill will track across the Ohio Valley, central Appalachians and into the mid-Atlantic this weekend with localized torrential rain and the potential for flooding.
According to AccuWeather Chief Meteorologist Elliot Abrams, the slow-moving nature of Bill will be an exacerbating factor with long-lasting rain and repeating showers and thunderstorms in some cases.
"Any place along the path of Bill will be at risk for street flooding, rapid rises along small streams, travel delays and disruptions to outdoor activities," Abrams said.
During Friday night, Saturday and Saturday night, drenching downpours will spread eastward from the middle Mississippi Valley to the Ohio Valley.
During Saturday night and Sunday, locally heavy rain and thunderstorms will push through the central Appalachians and mid-Atlantic.
The downpours will affect southern New England on Sunday into Sunday night.
According to AccuWeather Senior Meteorologist Henry Margusity, the atmospheric setup, topography and urbanization will play a role in the flooding.
"A pulse of heavy rain and flooding associated with the remnants of Bill could focus on northern West Virginia and neighboring portions of northwestern Virginia, northern Maryland, southern Pennsylvania, northern Kentucky and southern Ohio Saturday night into Sunday," Margusity said.
There is the potential for rises on some of the rivers including the Ohio, Potomac, Youghiogheny, Scioto, Lehigh, Raritan and Monongahela.
In a significant part of the Ohio Valley, 3-6 inches of rain is forecast with locally higher amounts.
In part of the mid-Atlantic states, 1-3 inches of rain is forecast but amounts can also be higher at the local level, especially in the central Appalachians and perhaps near the Atlantic coast.
Metro areas such as St. Louis; Cincinnati; Pittsburgh; Philadelphia; Baltimore; Washington, D.C.; New York City; Louisville, Kentucky; and Morgantown, West Virginia, could be hit with urban flooding and travel disruptions.
For some of the urban areas it will be the type of rainfall that can collect in underpasses, on lawns and in poor drainage areas along highways. Torrential downpours during the event will cause poor visibility for motorists and low cloud ceilings at area airports.
Showers and storms associated with a front dropping in across the Upper Midwest and southern Canada may be enhanced by Bill's moisture in some locations of upstate New York and northern New England.
The zone from around Bill to the front will be strewn with locally drenching showers and storms.
By the time Bill crosses the Appalachians, it will have little wind energy left. However, locally gusty thunderstorms can still occur with the potential for downed tree limbs and perhaps sporadic power outages.
Regardless of whether or not rain is associated with Bill or the front, there is a likelihood of drenching downpours affecting many areas of the Northeast during the Father's Day weekend.