Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 247 AM EST Mon Nov 19 2018 Valid 12Z Mon Nov 19 2018 - 12Z Wed Nov 21 2018 ...Light to moderate snow accumulations for portions of the Upper Great Lakes and Northeast... ...Air Quality and Air Stagnation Alerts continue over portions of California, Oregon and Washington... ...Moderate rain to impact California by Wednesday... A front extending from the Northern Mid-Atlantic to the Central Gulf Coast will move off most of the Eastern Seaboard and the Gulf Coast by Tuesday evening. The system will produce rain and snow over parts of the Eastern Ohio Valley to the Northeast through Tuesday evening when the rain moves off the East Coast. The rain will change over to all snow over parts of Eastern Ohio Valley/Central Appalachians by Tuesday afternoon and continuing into Tuesday evening. Showers and thunderstorms will develop along the associated boundary over parts of the Lower Mississippi Valley/Western Gulf Coast that will move out over the Gulf of Mexico by Tuesday afternoon. Rain will also develop along the front from parts of the Western Ohio Valley southwestward to the Lower Mississippi Valley that will dissipate over the Tennessee Valley/Southeast by Tuesday afternoon, too. Rain will also develop over parts of the Southern Mid-Atlantic/Southeast Coast on Monday ending by Monday evening. Meanwhile, a second front extending from the Great Lakes southwestward to the Northern Plains will move eastward to the Great Lakes/Northern New England southwestward to the Central Plains by Monday evening and begin to dissipate overnight Monday. The system will produce light snow over parts of the Upper Great Lakes to parts of the Northern Plains on Monday that will end over the Northern Plains by Monday evening. The snow will continue over parts of the Lower Great Lakes into Northern New England through Tuesday evening. A wave of low pressure over Central Canada will move southeastward to the Upper Great Lakes by Tuesday evening. Ahead of the low, lake effect/enhanced snow will develop over parts of the Upper Great Lakes through to Tuesday afternoon. On Tuesday afternoon, snow associated with the low moves into the Upper Great Lakes and continue through Wednesday morning. Air Quality and Air Stagnation Alerts continue over portions of California, Oregon and Washington through Tuesday. On Tuesday evening a front out over the Eastern Pacific will move close to the West Coast by Wednesday morning. Overnight Tuesday rain will begin to develop along West Coast. In addition, a marginal risk of excessive rainfall will be over parts of California on Wednesday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php