Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 356 AM EDT Wed Sep 22 2021 Valid 12Z Wed Sep 22 2021 - 12Z Fri Sep 24 2021 ...Widespread heavy rains likely with flooding possible from the Great Lakes to the central Appalachians on Wednesday... ...Strong to severe storms possible across the upper Ohio Valley and central Appalachians on Wednesday... ...Heavy rain threat expected to shift farther east across the northern Mid Atlantic on Thursday... Widespread showers and thunderstorms will continue to fall along a strong cold front that extends from the Great Lakes to the central Gulf Coast on Wednesday. A strengthening area of low pressure will move northeastward along the front from the lower Ohio Valley into the Great Lakes -- supporting gusty winds and heavy rains across the region. As a very moist airmass surges north into the region, widespread heavy rainfall accumulations are likely, with several inches possible in some locations from Indiana and Lower Michigan to the central Appalachians on Wednesday into early Thursday. Localized to widespread flooding is possible, with flood and flash flood watches currently in effect for portions of the region. In addition to the heavy rains, scattered strong to severe thunderstorms, producing damaging winds and perhaps a few tornadoes, are possible as well -- especially across the upper Ohio Valley and the central Appalachians Wednesday afternoon into the evening hours. As the low begins to track across the Great Lakes into southern Ontario, the front will slowly push farther east -- shifting the focus for heavier rains into the northern Mid Atlantic region on Thursday. Behind the front, high pressure and dry conditions are expected to prevail across the Plains through Thursday. Farther west, a weak cold front is expected bring some cooler temperatures and a chance for light precipitation as it moves across the Northwest into the northern Rockies on Wednesday. Pereira Graphics are available at www.wpc.ncep.noaa.gov/basicwx/basicwx ndfd.php