Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 250 AM EST Tue Dec 25 2018 Valid 12Z Tue Dec 25 2018 - 12Z Thu Dec 27 2018 ...Heavy snow possible for parts of the Central Rockies and Northern/Central Plains... ...Heavy rain possible over parts of the Southern/Central Plains... ...Post-Christmas winter storm to bring heavy snow from the Central Plains through the Great Lakes... Upper-level energy over the Middle Mississippi Valley/Western Ohio Valley will aid in producing rain over parts of the area that will end by afternoon on Christmas. Another area of upper-level energy over the Upper Great Lakes will produce light snow over parts of the Upper Great Lakes through Wednesday morning. Meanwhile, a developing upper-level low over California will move eastward to the Southern Rockies/Southern High Plains by Wednesday evening. The storm will produce rain and higher elevation snow over Northern/Central California and snow over parts of the Great Basin/Northern Intermountain Region. The rain ends over Northern/Central California by afternoon on Christmas. Rain will also move into Southern California by Christmas afternoon, too. Overnight Christmas, snow will expand into parts of the Northern/Central Rockies, while rain and higher elevation snow develops over parts of the Southwest. As the storm moves eastward, moisture from the Western Gulf of Mexico will flow northward over the Southern Plains into the Central Plains and the Middle/Lower Mississippi Valley. The moisture will aid in producing showers and thunderstorms over parts of the Southern Plains by evening on Christmas, expanding into parts of the Central Plains by Wednesday morning. The showers and thunderstorms will continue over parts of the Central/Southern Plains into Wednesday evening. By Wednesday morning, snow will develop over parts of the Northern/Central Rockies expanding into parts of the Upper Mississippi Valley by Wednesday evening. Also on Wednesday, rain will develop over parts of the Central Plains and the Lower/Middle Mississippi Valley expanding into parts of the Western Ohio Valley by Wednesday evening. Furthermore, a front will move onshore over the Pacific Northwest on Wednesday moving inland by Wednesday evening. The system will produce rain and higher elevation snow over parts of the Pacific Northwest by Wednesday afternoon that will expand into parts of the Northern Intermountain Region by Wednesday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php