Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 310 PM EST Sun Jan 17 2016 Valid 00Z Mon Jan 18 2016 - 00Z 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... An arctic airmass bringing sub-zero temperatures and dangerous wind chills to the Northern Plains will slide eastward behind a cold front. Wind chill advisories are in effect from the Northern Plains to the Ohio Valley where winds and bitter cold will combine to make it feel like 20 to 40 below zero. This frigid airmass moving over the relatively warm waters of the Great Lakes will generate lake effect snows across the region. Lake effect snow warnings are in effect downwind of Lake Superior, Lake Ontario, and Lake Erie where well over a foot of snow will be possible in the most persistent bands. Winter weather advisories are in effect along the eastern shore of Lake Michigan where generally 4 to 8 inches are expected. The cold weather will overspread much of the eastern U.S. by tomorrow with below normal temperatures expected as far south as Florida. In the west, a series of storm systems will bring several rounds of moderate to heavy rainfall to Northern California, Oregon, and Washington. The first storm coming ashore today will focus rainfall across Northern California, where flash flooding will be a concern. Rainfall will taper off by tomorrow morning, with the next system bringing precipitation to Oregon and Washington by the evening. A third storm will approach Northern California by the end of the period. Krekeler Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php