Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 333 PM EST Fri Nov 17 2017 Valid 00Z Sat Nov 18 2017 - 00Z Mon Nov 20 2017 ...Heavy precipitation possible over the Olympic Peninsula... ...Heavy precipitation possible over parts of the Ohio Valley/Lower Great Lakes... A front extending from the Middle Mississippi Valley/Central Plains into Central Rockies/Southwest will move eastward to the East Coast by Sunday. Showers and thunderstorms will develop along and near the warm front over the Middle Mississippi Valley that will expand into the Ohio Valley overnight Friday. On Saturday afternoon, the showers and thunderstorms will develop along and ahead of the cold front from the Ohio Valley into the Lower Mississippi Valley that will change over to rain overnight Saturday from the Lower Great Lakes to the Lower Mississippi Valley/Central Gulf Coast that will move to the East Coast by Sunday morning. In addition, the system's upper-level energy over the Great Basin into the Northern Rockies that will likewise, move to the Northeast/Mid-Atlantic by Sunday. The energy will aid in producing snow and lower elevation rain over parts of the Great Basin/Central Rockies that will slowly end over the area by Saturday morning. Meanwhile, another front over the Upper Great Lakes/Upper Mississippi Valley roughly northwestward to the Northern High Plains into West-Central Canada will undergo a metamorphosis as the eastern half of the boundary separates on Saturday while moving into Canada by Sunday morning. Rain and snow will develop along the eastern parts of the front over the Upper Great Lakes/Upper Mississippi Valley that will changeover to rain by Saturday morning over the Great Lakes. rain will also develop over parts of the Central Plains/Middle Mississippi Valley overnight Friday that will end by Saturday afternoon. More to Follow Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php