Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 337 AM EDT Tue Sep 29 2015 Valid 12Z Tue Sep 29 2015 - 12Z Thu Oct 01 2015 ...Widespread heavy rains possible across portions of the eastern U.S.... Widespread moderate to heavy rains are likely across portions of the Tennessee and Ohio valleys northeastward across the central Appalachians, northern Mid-Atlantic, into the Northeast as a cold front emerging from the Midwest interacts with an upper level disturbance and copious amounts of moisture lifting out of the Southeast. Through early Tuesday, showers and thunderstorms are expected to continue ahead of an upper disturbance lifting from the eastern Gulf coast across Alabama and Georgia. A broad area of low pressure centered further to the west will continue to direct ample moisture from the tropics, fueling these storms. Meanwhile, a cold front currently extending from the Great Lakes back into the central Rockies will continue to provide the focus for showers and storms as it continues to slide further to the south and east later today. Widespread heavy rains are expected to develop along the front by Tuesday evening as it pushes into the upper Ohio valley, central Appalachians and northern Mid-Atlantic, where it is expected to interact with the aforementioned disturbance and abundant moisture lifting from the south. Tuesday night into Wednesday, these rains are expected to shift north and east across the northern Mid-Atlantic and Northeast. Over the course of the event, several inches of rain may accumulate across portions of the central Appalachians northeastward into the northern Mid-Atlantic and Northeast -- resulting in flash flooding concerns. Refer to the WPC Excessive Rainfall outlooks for further details. Further to the west, showers and thunderstorms are possible today behind the front dropping across the central Great Plains and Rockies. Moist easterly winds are expected to support storms across portions of Kansas and Nebraska back into eastern Colorado and Wyoming. Elsewhere across the West, expect mostly dry conditions, with seasonal to above average temperatures. Pereira Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php