Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 253 AM EST Wed Dec 27 2017 Valid 12Z Wed Dec 27 2017 - 12Z Fri Dec 29 2017 ...Freezing rain possible over parts of the Pacific Northwest with snow in the Cascades and northern Rockies... ...Great Lakes to experience lake effect snow... ...Chance for mixed precipitation across parts of the Southeast... A steady stream of onshore flow will continue to spread rain and snow to the higher elevations of the Northwest, Northern Rockies and the adjacent High Plains. As a strong Pacific front moving onshore there will be a significant uptick on the amount of moisture moving into the region. Precipitation amounts will increase...also, pockets of freezing rain will be possible in the lower elevations in western Washington and Oregon. The heaviest snow will occur beyond the short term period. See WPC's winter weather products for more information. A stalled frontal boundary over the Great Lakes region will continue to provide a focus for snow generation. And, with the persistent westerly winds and cold air traveling across the Great Lakes region, heavy lake effect snow will continue downwind of the lakes. This setup will become less favorable once the Arctic high pressure shifts toward the Great Lakes on Thursday. A vast area spanning from the High Plains to New England have continue to be affected by the Arctic airmass. Wind Chill Advisories, along with a handful of Wind Chill Warnings are in effect. Showers are expected across much of the Gulf states as warm, moist air transports northward along a wavy frontal boundary. This boundary and area of precipitation toward the central Gulf Coast. Precipitation will continue across the Southeast and the southern portions of South Carolina. However, with a shallow cold airmass in place--mixed precipitation and/or freezing rain could occur in parts of western Texas today and for Thursday into Friday for central Georgia to southeastern South Carolina. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php