Flash Flood Threat from Kentucky and West Virginia to the Mid-Atlantic and Northeast

Brian Donegan
Published: July 28,2016
A disconcerting forecast is in store from the Ohio Valley and Appalachians, including flood-ravaged West Virginia, into the mid-Atlantic and Northeast through Friday evening as a series of disturbances enhances the risk for heavy rain and flash flooding.
A moisture-filled area of low pressure in the upper atmosphere is sliding through the Ohio Valley and mid-Atlantic, beginning a two-day threat of heavy rain and flash flooding.
(MORE: Deadly West Virginia Flooding Leaves Thousands Homeless)

Current Radar with Watches and Warnings

(MORE: View National Interactive Radar Map | Difference Between a Watch and a Warning)
Early Thursday morning, over 3 inches of rain in 2 hours swamped parts of the Cincinnati metro area, stranding numerous vehicles in Anderson Township. In Bellevue, Kentucky, more than 20 homes were flooded with water up to 6 feet deep.
On Thursday evening, roughly 2 inches of rain fell in about an hour in Manhattan, Kansas, causing flash flooding on area roadways.
The National Weather Service has placed several states from the Ohio Valley to the mid-Atlantic and Northeast under flash flood watches.

Current Flood Alerts

How Much Rain?

One to three inches of rainfall is in the forecast over a broad swath from western Tennessee and Kentucky eastward through West Virginia and into the I-95 corridor, including Washington D,C., Philadelphia and New York City.
(FORECAST: Charleston | Louisville | Memphis)
Into Thursday evening, the heaviest rain should largely remain near the Appalachians, west and southwestward into the Ohio and Tennessee valleys.
Friday, that heavy rain threat will concentrate primarily from the mid-Atlantic states into parts of southern New England.
Any thunderstorms that train, or re-form over the same area for several consecutive hours, have the potential to dump over three inches of rain. This is why flash flooding will be a concern into Friday evening.
(MORE: Three Drought Areas You May Not Have Heard About)

Rainfall Forecast

Setup for Flash Flooding

As an upper-level low that had been over the lower Mississippi Valley slides into the Ohio Valley into Thursday evening, a tropical air mass will set up over the region.
Meanwhile, a stalled front is already in place over the area, and the interaction of these two features will set the stage for potentially heavy rainfall.
(MORE: Severe Storms Threaten the Plains, Mid-Atlantic)

Low pressure will develop at the surface Thursday night and push eastward into Friday and Friday evening, riding along the stationary front.
As the low moves east, the threat for flash flooding will extend into portions of the mid-Atlantic region, possibly even up into the Northeast in places like Philadelphia, New York City and Boston.
MORE: West Virginia Flooding in June