Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 116 PM EST Mon Dec 25 2017 Valid 00Z Tue Dec 26 2017 - 00Z Thu Dec 28 2017 ...Freezing rain possible over parts of the Pacific Northwest... ...Expect snow across the Cascades and northern Rockies... ...Great Lakes to experience lake effect snow... A wavy frontal boundary will stalled along the Pacific Northwest to the central Rockies through most of the short term period. This boundary will bring an increase in precipitation across the Pacific Northwest--particularly in the higher terrain as snow. Precipitation will taper off by late tonight/Tuesday morning--with snow in the northern Rockies and parts of the central Rockies continuing through the morning. As a another system approaches the Pacific Northwest on Tuesday evening, onshore flow will encourage precipitation to spread across the region late night and into Wednesday. Some of this precipitation will fall as freezing rain across the region along with heavy snow in the Cascades and northern Rockies. Expect the precipitation to be ongoing into Wednesday night. With westerly flow moving across the Great lakes region, cold air will travel over the lakes and give way to heavy lake effect snow downwind of the lakes. This activity will continue throughout the short term period--as such, lake effect snow warnings are in effect for parts of the Great Lakes. See WPC's winter weather products for more detail. As a front lifts northward as a warm front across the Gulf of Mexico, southerly winds will bring moisture from the Gulf into South and Southeast Texas by Tuesday morning. Showers will move into coastal Texas by Tuesday and will spread eastward into the central Gulf Coast by Wednesday morning a the front continues lifting north. Overall, very cold conditions--with maximum temperature values of 10 degrees and below--will exist over the northern Plains and Upper Midwest on Monday and Tuesday. These temperatures will warm up slightly by Wednesday as the Arctic air spreads into New England and down into the southern Plains. The West Coast will experience near normal, if not slightly above normal, temperatures through the beginning of the week. Reinhart Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php