Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 331 PM EDT Fri Mar 13 2015 Valid 00Z Sat Mar 14 2015 - 00Z Mon Mar 16 2015 ...Widespread heavy rain from the Mississippi Valley and Southeast to the Mid-Atlantic, with flash flooding possible across the Ohio Valley... ...Wintry weather returns to portions of the Great Lakes and New England... ...Another round of rain and high mountain snow for the Northwest expected this weekend... As significant moisture streams northward out of the Gulf of Mexico ahead of a surface cold front, widespread heavy rain across the Mississippi Valley, Southeast, and Ohio Valley this afternoon will spread into the Mid-Atlantic by tonight and throughout the day on Saturday. In addition to heavy rain, flash flooding may also be a concern across portions of the Ohio Valley tonight into tomorrow morning. On Saturday, this southern stream front will eventually merge with a northern stream front moving across the Great Lakes pulling the precipitation into the Northeast. From the Great Lakes to northern New England, precipitation should fall as snow, with sleet and freezing rain expected across remaining portions of the Northeast and southern New England. By Saturday afternoon, a surface low is expected to develop along the New England coastline, and bring the possibility for accumulating snows to northern New England and Maine Saturday night into Sunday. Meanwhile, out west, the weekend is looking wet as a series of disturbances aloft and a surface cold front approach the West Coast. Rain will spread across the Pacific Northwest into the Intermountain West tonight through Sunday. The most organized of the precipitation is expected along the Washington and northeast Oregon coasts, as well as along favorable slopes of the northern Rockies. Any snow that falls will be confined to the highest terrain of the Washington Cascades and the Canadian Rockies. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php