Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 410 PM EDT Fri Oct 05 2018 Valid 00Z Sat Oct 06 2018 - 00Z Mon Oct 08 2018 ...The beginning of a multi-day heavy rain event for the central to southern Plains is expected to begin tonight... ...Significantly colder than average out West into the central and northern Plains while significantly warmer than average out East for the weekend... ...Accumulating snow from the Intermountain West into the central and northern Rockies... The upper level pattern across the lower 48 will become highly amplified through Sunday with the jet stream diving south into the western U.S. while returning north through the middle of the nation. The trough (West) and ridge (East) pattern will allow for a relatively active weather pattern over the next few days. At the surface, a strong front will separate two distinctly different air masses with high temperatures on Saturday and Sunday forecast to be in the 80s to low 90s from the Ohio Valley and Mid-Atlantic region into Texas and the Southeast. These temperatures are 10-20 degrees above early October averages, with the greater departures to occur across the Ohio Valley into Upstate New York. Meanwhile, the cold side of the frontal boundary will feature highs in the 40s and 50s for the central and northern Plains into portions of the Intermountain West. High temperature departures on Sunday cross the central to northern High Plains could be as cold as 30 degrees below average with temperatures hovering on either side of 40F. Temperatures will be cold enough to support snow in locations of higher terrain from the Great Basin into the central and northern Rockies as well as the Black Hills of South Dakota. Some of the more significant accumulations are expected to begin Saturday night lasting into Sunday across the Rockies into the Black Hills as colder temperatures filter down from the north. Accumulations in excess of 6 inches are forecast for the Wasatch, Tetons, Big Horns and Black Hills to name a few. Meanwhile, the transition between the two air masses will become slow moving beginning tonight and develop as a focus for rainfall. Some of the rainfall could be heavy across portions of the upper Midwest tonight, with locations from Texas, Oklahoma into eastern Kansas and Missouri becoming a focus for heavy rainfall and possible flash flooding Saturday into Sunday. These rains are expected to be the beginning of a multi-day heavy rain event to impact portions of the central to southern Plains lasting into next week. Otto Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php