Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 300 PM EST Tue Dec 18 2018 Valid 00Z Wed Dec 19 2018 - 00Z Fri Dec 21 2018 ...Unsettled weather continues in the West, with rain, snow, high winds, and even avalanches possible... ...Wet weather develops across the southern and eastern U.S.... In the western U.S., active weather is ongoing as strong onshore flow continues through Tuesday night and a front moves through the Intermountain West. Precipitation will remain rain along the coast and in lower elevations, and snow in the mountains. A Marginal Risk of excessive rainfall is in place through Tuesday night, with a small Slight Risk for far southern Oregon and far northern California, with burn scars particularly threatened by flooding. In the mountains, heavy snow continues, especially for the Washington Cascades, where an additional 1 to 2 feet of snow is forecast. Additionally, high wind is a threat in the Intermountain West and into the Northern/Central Rockies. Avalanche Warnings are in effect for parts of Washington and Oregon through Tuesday evening. Precipitation chances will briefly lower on Wednesday before another low pressure system approaches on Wednesday night and another round of rain and snow begins. As the first frontal system currently moving through the West propagates eastward, rain and snow showers will develop across the Northern Plains Tuesday night and into Upper Midwest Wednesday. Some light freezing rain is also possible. Temperature-wise, those areas will remain much above average over the next few days, with some record high minimum temperatures possible. Most of the rest of the U.S. will remain at or above normal too, though cooler weather is expected in the Lower Mississippi Valley. An upper-level trough is forecast to move eastward through the Plains, and surface lows will develop and track eastward with it. This will cause increasing rain and thunderstorm chances for the southern and eastern U.S. Scattered showers and storms are expected to form in the Southern Plains Tuesday night, moving into the Lower Mississippi Valley and Southeast on Wednesday. By Wednesday night and Thursday, rain will spread north and east into the Tennessee and Ohio Valleys and Mid-Atlantic. Rain totals will generally be under an inch, with locally higher amounts, in the Southern Plains, Lower Mississippi Valley, and Tennessee Valley. However, Florida and the coast of Georgia and the Carolinas are expecting heavier rain, so Slight Risks of excessive rainfall are in place for Thursday. There is also a Slight Risk of severe weather for portions of Florida on Thursday. Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php