Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 314 AM EST Thu Dec 12 2019 Valid 12Z Thu Dec 12 2019 - 12Z Sat Dec 14 2019 ...Heavy snow in the mountains of the Pacific Northwest and Northern/Central Rockies... ...Periods of snow over to develop over the Upper Midwest and Upper Great Lakes... ...Widespread showers across the Southeast and rain/freezing rain in the Central Appalachians on Friday... A storm over the Middle Missouri Valley will move northeastward into the Upper Great Lakes by Friday. The system will produce light snow over parts of the Northern Plains into the Upper Great Lakes on Thursday through Friday afternoon. Another wave of low pressure over the Northern High Plains/Canadian border will move eastward across the Upper Midwest into the Upper Great Lakes by Saturday. The storm will produce snow over parts of the Northern Plains overnight Thursday expanding into the Upper Mississippi Valley by Friday evening and into the Upper Great Lakes overnight Friday. The NWS has issued Winter Weather Advisories and Winter Weather Warnings over the Upper Great Lakes. Meanwhile, upper-level energy will move across the Pacific Northwest and advance to the Upper/Middle Mississippi Valley by Saturday. Onshore flow off the Pacific Ocean will accompany the upper-level energy aiding in producing rain and higher elevation snow from the Pacific Northwest/Northern California eastward to the Northern/Central Rockies through Saturday. Winter Weather Advisories and Winter Weather Warnings are posted across the higher elevations of the West, likewise through Saturday. Furthermore, upper-level energy over the Texas Panhandle will move eastward to the Southern Appalachians by late Thursday night followed by more upper-level energy that will induce a wave of low pressure over a boundary over the Northern Gulf of Mexico on Friday afternoon. The wave of low pressure will travel to the Southeast Coast by Friday evening and northward to the Northern Mid-Atlantic Coast by Saturday. The upper-level energy will aid in pulling moisture northward from the Gulf of Mexico and Atlantic Ocean over the Southeast producing light rain over parts of the Southeast on Thursday evening that will expand northward into parts of the Mid-Atlantic and the Ohio/Tennessee Valleys by Friday morning and continue to move northward into the Lower Great Lakes and the Northeast overnight Friday into Saturday. Overnight Thursday, rain/freezing rain will develop over parts of the Southern Appalachians into the Piedmont moving into parts of the Central Appalachians and Piedmont on Friday that will linger over the area into Friday night. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php