Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 257 PM EST Wed Dec 27 2017 Valid 00Z Thu Dec 28 2017 - 00Z Sat Dec 30 2017 ...Freezing rain possible over parts of the Pacific Northwest with snow in the Cascades and northern Rockies... ...Light snow for the northern Plains along with continuing lake effect snow... ...Chance for mixed precipitation across parts of the Southeast... As a steady stream of onshore flow continues bringing moisture across the Pacific Northwest, showers and higher elevation snowfall also persists throughout the region. By Thursday afternoon, another frontal system in the Pacific approaches the area which will bring a robust plume of moisture to the Pacific Northwest. This will bring to widespread showers and snow across the Cascades and northern Rockies. In addition, pockets of freezing rain will also be possible in the south and west portions of Washington and northern Oregon. Precipitation will increase even more by Friday--bringing even heavier snowfall especially to the northern Rockies and continuing the areas of freezing rain. Expect this activity to persevere into the weekend. A clipper system will deliver snow across the northern Plains to the Upper Midwest on Thursday--although widespread snow is not expected. Meanwhile, westerly winds will maintain promotion of lake effect snow downwind of the lakes this evening. Snow amounts will lighten up by Thursday especially in the lower Great Lakes; however, as the clipper system approaches the upper Great Lakes, this will enhance lake effect snow for that region. As the system moves eastward--lake effect snow will also ramp up for the lower Great Lakes. In addition, New England will still have an Arctic airmass overhead. Thus, wind chill warnings and advisories are in effect. A wavy front in the Gulf of Mexico along with upper level energy sweeping across the Southeast will spread moisture across the Gulf Coast states. Light showers are expected especially in the central and eastern Gulf coast. With a shallow cold airmass in place, light mixed precipitation and/or freezing rain could occur in parts southeast Georgia to southern South Carolina. See WPC's winter weather products for more information. Reinhart Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php