Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 318 PM EST Thu Dec 14 2017 Valid 00Z Fri Dec 15 2017 - 00Z Sun Dec 17 2017 ...Heavy lake effect/lake enhances snow possible downwind from the Great Lakes... ...Heavy snow possible over parts of the Cascades and the Northern Rockies... ...Heavy rain possible over parts of southern Texas... A region of strong upper-level energy over Western Ontario/Upper Mississippi Valley will move across the Great Lakes to off the Northeast Coast by Saturday. Lake effect/lake enhances snow will develop over the Great Lakes through Saturday with snow heavy at times. The associated front will also aid in producing snow over parts of the Northeast and Upper Mississippi Valley/Northern Plains also through Saturday. In addition, upper-level energy over the over the Central Plains will move to the Lower Mississippi and Tennessee Valleys by Friday morning. The energy will trigger light snow over parts of the Northern/Central Plains that will end by late evening on Thursday. Meanwhile, onshore flow develops over parts of the Pacific Northwest overnight Thursday into Saturday. The flow will aid in producing coastal rain and higher elevation snow over the Pacific Northwest through Saturday. Additionally, upper-level energy and associated upper-level trough will move onshore over the Northwest on Friday evening that will move southeastward to the Northern Intermountain Region to Central California by Saturday morning. The energy will aid in producing snow over parts of the Northern Intermountain Region/Northern Rockies into parts of the Great Basin Friday evening into Saturday. Elsewhere, a front over the Gulf of Mexico will stall while a wave of low pressure will move westward to the Mexican Coast on Friday into Saturday. Rain will develop over parts the southern tip of Texas overnight Thursday into Saturday morning. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php