Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 344 PM EST Mon Jan 04 2016 Valid 00Z Tue Jan 05 2016 - 00Z Thu Jan 07 2016 ...Heavy snow possible for the Sierras and portions of the Great Basin... ...Heavy rain possible for coastal California... ...Below average temperatures expected for the eastern U.S... The weather pattern across the western U.S. will be unsettled over the next few days as a series of storm systems from the Pacific affects the region. A Pacific frontal system will move into the West Coast tonight, with rain and high elevation snows increasing in coverage and intensity. Winter storm warnings are in effect for much of the Sierras, where heavy snow may lead to significant travel impacts. Through Tuesday evening, snowfall amounts of 5 to 15 inches are expected in the Sierras, with amounts approaching 2 feet at the highest peaks. The system will spread snow into the Great Basin on Tuesday, with 4 to 8 inches of snow possible. Farther north, snow will also fall in the Washington Cascades, where 3 to 8 inches of snow are possible. Another Pacific frontal system will move into the region on Wednesday, spreading more snow into the Sierras. Snowfall accumulations of 1 to 2 feet, with locally higher amounts, will be common in the Sierras through Wednesday. Gusty winds will accompany the snow at higher elevations. Additionally, heavy rain will be possible along the coast in California, with one round of rain on Tuesday and another on Wednesday. Sufficient instability will exist for the possibility of some thunderstorms across coastal California and the Central Valley on Tuesday as well. Rainfall amounts of 1 to 4 inches, with locally higher amounts, are possible across coastal California through Wednesday. These heavy rainfall amounts could lead to flooding in some areas. Moisture from the Gulf of Mexico will increase across the central U.S. by Tuesday night into Wednesday. A cold air mass in place will allow for a relatively light mix of rain, snow, sleet, and freezing rain across portions of the central U.S. on Wednesday. Farther east, a cold air mass will remain in place, with afternoon high temperatures on Tuesday across the eastern U.S. expected to be 5 to 15 degrees below average. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php