Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 222 AM EST Sat Feb 17 2018 Valid 12Z Sat Feb 17 2018 - 12Z Mon Feb 19 2018 ...Snow possible for parts of the Central Appalachians/Northern Mid-Atlantic into southern New England... ...Heavy snow possible for the Cascades and the Northern Rockies... ...Heavy rain possible over parts of the Pacific Northwest... A vast portion of the Pacific Northwest, Great Basin and Intermountain West will be impacted over the next few days with as heavy rain and heavy snow overspread the region. Arctic air will quickly surge southward as the low pressure system moves inland. Strong onshore flow will generate heavy coastal rains and mountain snow, which will spread toward the Rockies and south into the Great Basin as the front pushes through the Southwest and Central/Southern Rockies by early Monday. Cold Canadian air will surge into the Northern and Central Plains, allowing temperatures to fall to below normal for mid-February. Snow will accompany the front as it makes its way through the Upper Mississippi Valley and Great Lakes region this weekend and into portions of the Northeast on Monday. A front extending from the Southern Mid-Atlantic to the Western Gulf Coast will have a wave of low pressure develop over the Central Gulf Coast that will travel to the northeast along the boundary. The boundary will settle southward over the Southeast by Sunday morning as well. Scattered to widespread rain will span from the Southern Plains to the Mid-Atlantic region. Higher rainfall amounts/rates across portions of the eastern Tennessee Valley/Central Appalachians today will may increase the risk for flooding. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php