Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 218 AM EST Sat Dec 22 2018 Valid 12Z Sat Dec 22 2018 - 12Z Mon Dec 24 2018 ...Heavy snow possible over the Cascades... ...Heavy rain possible over parts of the Pacific Northwest... A strong storm moving into Southeastern Canada will move northeastward to the Davis Strait by Sunday morning. The storm will bring rain to New England and snow from the Lower Great Lakes into the Central Appalachians that will start to wane by Saturday evening. The rain over New England will change over to snow by Saturday evening, too. The precipitation will end overnight Saturday over the Northeast. Meanwhile, another storm over Northern Plains/Upper Mississippi Valley will move eastward to the Lower Great Lakes by Sunday evening. The system will produce snow over parts of the Upper Midwest that will move into the Upper Great Lakes by Sunday afternoon and into the Lower Great Lakes by Sunday evening. Rain will develop along the associated front over the Tennessee Valley into parts of the Central Gulf Coast on Sunday morning. The rain will expand along the boundary and move eastward to parts of the Lower Great Lakes/Ohio Valley southwestward into the Eastern Gulf Coast by Sunday evening. In addition, an area of upper-level energy over the Northern Rockies will move southeastward to the Southern Ohio and Tennessee Valleys by Sunday evening. The energy will produce snow over parts of the Central Rockies on Saturday morning that will move to the Central High Plains before dissipating overnight Saturday. Furthermore, upper-level energy over the Eastern Pacific will move onshore over the Pacific Northwest overnight Saturday into Sunday. Rain and higher elevation snow will develop over parts of the Northwest on Saturday that will expand inland over the Northwest overnight Saturday. The snow will continue to expand eastward into the Northern Rockies by Sunday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php