Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 233 AM EST Fri Dec 26 2014 Valid 12Z Fri Dec 26 2014 - 12Z Sun Dec 28 2014 ...Snow is expected from the Rockies across the Central Plains, Upper Mississippi Valley into the Upper Midwest... ...Colder air is to become more widespread especially across the northern half of the nation while a significant cold outbreak starts to move southward into the Pacific Northwest and northern Rockies with mountain snow... ...Heavy rains to develop over the weekend along the Gulf Coast and parts of the Southeast... Snow will continue across the central Rockies on Friday and will spread northeastward across Central Plains, Upper Mississippi Valley and northern Great Lakes into Saturday. Colder air will follow in the wake of this system as a cold front presses south and eastward toward the western Gulf by Saturday. A weak area of low pressure is expected to develop near the central Gulf late Saturday and move northeastward into the southeastern states on Sunday...with locally heavy showers and thunderstorms extending from eastern Texas across the central Gulf into the Southeast. Heavy rain could result in localized flash flooding. Colder air will make its way slowly eastward across the Ohio Valley and into the Northeast on Sunday and Monday while some very cold air begins to make its way south from southern Canada into the Northern Plains into the Upper Mississippi Valley and northern Midwest by early Monday. Meanwhile...a storm system is expected to move southeastward from the northeast Pacific across SW Canada into the Pacific Northwest starting on Saturday and continuing south and eastward toward the northern Rockies on Sunday. A large Arctic High is expected to follow in its wake from northwestern Canada bringing much colder air across many portions of the Pacific Northwest, Great Basin and northern Rockies by early Monday. Bitterly cold air will really make its presence felt by early in the week especially along the eastern slopes of the Rockies into the central and northern Plains, where subzero temperatures will make its presence felt. Kocin Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php