Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 341 AM EST Fri Dec 25 2015 Valid 12Z Fri Dec 25 2015 - 12Z Sun Dec 27 2015 ...Flash flooding possible across portions of the Southeast, Tennessee and Ohio Valleys, Appalachians and Southern Plains... ...Heavy snow possible from portions of the Rockies into the Central and Northern plains Christmas Day and into the weekend... ...Snow expected to develop on Saturday from portions of the Southern Rockies to the southern High Plains... The overall pattern for the CONUS will be active through the weekend, with a vast majority of the country expecting precipitation. Light accumulations are expected over the next couple of days for the West Coast and southern Florida. A nearly stationary front, spanning from the Mid-Atlantic to the lower Mississippi Valley, will keep scattered to numerous showers and thunderstorms through the weekend for these regions. Periods of heavy rainfall is anticipated along the axis of this boundary, especially along the Appalachians, which may result in flash flooding. Temperatures are forecast to remain well above average on Christmas Day across much of the eastern half of the nation. The warmest temperatures will be along the Eastern Seaboard, where high temperatures more than 20 degrees above average are forecast. Above average temperatures will persist into the weekend from the lower/middle Mississippi valley eastward. Widespread snow is expected for portions of the Central Rockies, Central/Northern Plains and the Upper Midwest as a cold front surges southward from the southern Canada. Numerous Winter Storm Advisories and Warnings are effect with this system. Snow accumulations of 2 to 6 inches will be common over the next couple of days. Some areas, particularly in higher terrain, amounts may exceed 1 foot. Locations along and south of the advancing boundary may observe sleet or freezing rain. A robust low pressure system is forecast to develop and strengthen over the Southwest on Saturday. With an Arctic cold front trekking southward through the plains this could potentially become a significant winter storm. A vast area from New Mexico to Oklahoma is under a Winter Storm Watch and Blizzard Watch. Please refer to products issued by local NWS Forecast Offices for details specific to your area. Areas of accumulating sleet and freezing rain will be possible by Saturday evening across portions of the Southern/Central Plains. Snow accumulations 6 to 12 inches will be common across norther New Mexico to western Oklahoma; 1 to 2 feet possible for southern New Mexico and northern Texas. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php