Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 407 PM EDT Thu Apr 21 2016 Valid 00Z Fri Apr 22 2016 - 00Z Sun Apr 24 2016 ...Showers and thunderstorms are expected to bring an end to the week-long dry spell across the eastern U.S. on Friday... ...Active weather is expected to move across the western U.S. Friday and through the weekend... A stagnant weather pattern across the U.S. for the past week or so is beginning to break down as a low pressure system and the associated cold fronts begin to move steadily toward the eastern U.S. This will bring a good chance of showers and thunderstorms across the Eastern Seaboard on Friday, ending the week-long dry spell there. The tail end of the front will swing across the Deep South where the ground remains inundated by recent heavy rains. Any additional downpours will increase the chance of flash flooding tonight, especially from the Texas coast eastward into southern Louisian. By Friday, drier air will move into the area behind the cold front, which will continue to spread eastward into the Florida Panhandle on Saturday. Out West, unseasonably warm temperatures in the Pacific Northwest will give way to unsettled weather as the next Pacific front arrives. Steady rain is expected to move across the coastal regions, the Cascades, and northern California on Friday, with snow at the higher elevations of the Sierra Nevada, where 1 to 2 inches of precipitation can be expected. This system is expected to penetrate well inland, reaching the central Rockies on Saturday with high-elevation snow expected. By Saturday evening, the main low is forecast to move into the High Plains where the chance of showers and thunderstorms will increase. Meanwhile, colder air from Canada is expected to feed into the system from the north, where rain is expected for the northern Plains on Saturday. Temperatures could be cold enough for the precipitation to begin as a mix of rain and snow in the upper Great Lakes. Kong Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php