Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 437 PM EDT Thu Mar 16 2017 Valid 00Z Fri Mar 17 2017 - 00Z Sun Mar 19 2017 ...Heavy snow possible over the Northern Cascades... ...Snow possible over the Upper/Lower Great Lakes into parts of the Northern Mid-Atlantic... A front over the Northern Plains into the Northern Rockies will move eastward to the Lower Great Lakes and Central/Southern Appalachians westward to the Southern High Plains by Saturday. The system will produce rain and snow over parts of the Upper Mississippi Valley/Upper Great Lakes that will move eastward into parts of Eastern Ohio Valley by Friday afternoon and into parts of the Northern Mid-Atlantic overnight Friday into Saturday. Moisture from the Gulf of Mexico will stream into parts of the Southern Plains and pool along the front. Showers and thunderstorms will develop over parts of Eastern Texas into parts of the Lower Mississippi Valley on Thursday evening moving into the Middle Mississippi Valley by Friday morning. The showers and thunderstorms will move into parts of the Southern Ohio Valley/Tennessee Valley on Friday afternoon and extend from the Lower Mississippi Valley into parts of the Southern Mid-Atlantic by Saturday morning. Meanwhile, weak onshore flow will produce coastal rain and higher elevation snow over parts of the Pacific Northwest eastward to parts of the Northern Rockies that will slowly wane overnight Thursday as the onshore flow ends. On Friday, an upper-level trough will begin to move inland over the Pacific Northwest along with a plume of moisture that will start to produce rain along the Northwest Coast on Friday afternoon. Overnight Friday, rain and higher elevation snow will move into parts of the Northern Intermountain Region/Northern Rockies and rain into parts of Northern California. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php