Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 258 PM EST Thu Dec 08 2016 Valid 00Z Fri Dec 09 2016 - 00Z Sun Dec 11 2016 ...Heavy snow and rain possible over the Sierras... ...Heavy snow possible in favored areas downwind from the Great Lakes... ...Areas of rain and freezing rain possible over interior portions of the Pacific Northwest... ...Temperatures will be 15 to 35 degrees below average over the Rockies and High Plains... A cold front will move through California, the Pacific Northwest, the Great Basin and into the Intermountain region by this weekend - spreading rain to the coastal areas, a mix of rain and freezing rain to interior West and higher elevation snow across the Great Basin and Rockies. High pressure over the central and northern states will keep the arctic airmass in place over the High Plains. Downstream, upper-level energy and favorable upper-level flow will aid in producing lake effect snow downwind from the Great Lakes into parts of Northern New England into the weekend. To the south, upper-level energy moving over the Western and Central Gulf Coast States will aid in producing rain over parts of the Southern Plains and the Lower Mississippi Valley through Friday morning. Rain and embedded thunderstorms will also develop over the southern portion of Florida through Friday evening. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php