Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 355 AM EST Mon Jan 18 2016 Valid 12Z Mon Jan 18 2016 - 12Z Wed Jan 20 2016 ...Below-normal temperatures shifting from Northern Plains to Eastern U.S... ...Lake effect snow expected across the Great Lakes... ...Heavy precipitation possible for portions of the Pacific Northwest and northern California... The frigid airmass in place over the Northern Plains will slide eastward behind a cold front, overspreading most of the eastern U.S. by Monday evening. Brisk winds combined with the cold air will result in apparent temperatures of 20 to 40 below zero. A vast area spanning from the High Plains to the Ohio Valley, the Midwest and along the Appalachians have wind chill advisories in effect. Wind speed and direction with this system will favor lake effect snow for locations downwind of the Great Lakes. Winter Weather Advisories and Lake Effect Snow Warnings are in effect. Areas downwind of the lakes are forecast to pick up 6 to 10 inches of snow, possibly higher. A Heavy Freezing Spray Warning is in effect for a majority of Lake Superior. A series Pacific systems will move through the West bringing several rounds of moderate to heavy rainfall to Northern California, Oregon, and Washington. Flash flooding may become a concern during periods of intense rainfall, especially for northern California, where accumulations of 1 to 3 inches are possible. The next system will focus the brunt of the precipitation to Oregon and Washington tonight and into Tuesday. A third storm will approach Northern California by the end of the period. This means the Cascades, Sierras, Wasatchs, Bitteroots and portions of Central and Northern Rockies will have heavy snow as these systems advance through the Great Basin and Intermountain West. The highest elevations could see multi-day accumulations of 1 to 2 feet; with lower elevations receiving 2 to 8 inches. Showers and thunderstorms are expected to develop Tuesday through Wednesday along and ahead of the system moving through the Southern Plains. Areas just north of the warm front may see freezing rain/ice by early Wednesday morning as it lifts through the Middle Mississippi Valley. Ice accumulations up to 0.10 inch will be possible from eastern Kansas/Oklahoma to western Kentucky/Tennessee. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php