Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 227 AM EST Thu Dec 27 2018 Valid 12Z Thu Dec 27 2018 - 12Z Sat Dec 29 2018 ...Significant winter storm will impact the Central/Northern Plains and the Upper Midwest through the end of the week... ...There is a slight risk of severe thunderstorms over parts of the Lower Mississippi Valley... ...Heavy rain possible from parts of the Lower Mississippi Valley into the Mid-Atlantic... A strong storm over the Central Plains will move northeastward into Quebec by Friday evening. The storm will spread heavy snow and gusty winds to much of the Central/Northern Plains and Upper Midwest. Travel will be hazardous with slick snow-covered roads, especially in parts of the Dakotas where Blizzard Warnings are in effect. Showers and thunderstorms will develop along and ahead of the associated front over the Western Gulf Coast into the Lower Mississippi Valley that will move eastward to the Mid-Atlantic/Southeast by Friday evening. Rain will develop from parts of the Central/Southern Plains into the Middle Mississippi Valley and the Western Ohio Valley into parts of the Tennessee Valley that will move into the Great Lakes on Thursday. By Friday morning, rain will move into parts of the Northeast/Mid-Atlantic continuing into Saturday. Snow, heavy at times, will develop over parts of the Southern High Plains into Northern/Central Plains into the Upper Mississippi Valley/Upper Great Lakes on Thursday. The snow will end over the Southern Plains by Thursday evening and over the Northern/Central Plains by Friday evening. Overnight Thursday, snow will start over parts of Northern New England ending by Friday evening. In addition, pockets of rain/freezing rain will develop over parts of the Upper Mississippi Valley/Upper Great Lakes on Thursday ending by Thursday evening. Pockets of rain/freezing rain will also develop over parts of the Northeast overnight Thursday into Friday evening. Meanwhile, upper-level energy over the Pacific Northwest will move southward to the Great Basin/Southwest while forming an upper-level low by Friday morning. The energy will settle over the Central/Southern Rockies by Friday evening into Saturday. The storm will produce coastal rain and higher elevation snow over parts of the Pacific Northwest with snow extending into the Northern Rockies/Great Basin. The rain will end over the Northwest coast by Thursday evening. The snow will move southeastward into parts of the Central Rockies and Southwest by Thursday evening. The snow will end over the Northern Rockies overnight Thursday while expanding into Southern Rockies with rain over the lower elevations of the Southwest. The snow will taper off over most of the Great Basin on Friday. Furthermore on Friday, onshore flow will aid in producing rain and higher elevation snow over parts of the Pacific Northwest. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php