Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 AM EDT Tue Mar 20 2018 Valid 12Z Tue Mar 20 2018 - 12Z Thu Mar 22 2018 ...Severe thunderstorms expected across the Southeast and southern Mid-Atlantic region... ...Accumulating snow expected from parts of the Ohio valley, central/southern Appalachians into the Mid-Atlantic and southern New England... ...Coastal storm to potentially bring heavy snow and gusty winds to portions of the Northeast Coast on Wednesday... ...Heavy rain, possible flash flooding for portions of southern California... Both coasts will be in an active wet pattern over the next few days while the central U.S. remains fairly mild and dry. A storm system will continue to track through the Southern Appalachians, Southeast/Mid-Atlantic today generating scattered to widespread rain and thunderstorms. Several of these storms could become severe and also produce heavy rainfall. Much of this region is under an enhanced risk for severe weather from the Storm Prediction Center. A complex evolution of fronts and surface lows will evolve through Tuesday, as moisture moves northeastward into the eastern U.S. Cold air filtering into the Northeast and Mid-Atlantic will allow a changeover from rain to a wintry mix early Tuesday morning for portions of the Ohio valley and northern Mid-Atlantic region. Accumulations and coverage will increase across the Northeast as the system tracks northeast up the coast. The greater potential for heavier snowfall accumulations will be across the higher elevations of the Appalachians and into portions of New Jersey, the New York City metropolitan region and southern New England Tuesday night into Wednesday. Long duration of rain with flooding is expected for much of southern California. Relatively slow movement of this moisture axis will be directed toward the region and likely dump several inches of rain to the coastal areas and inland through Thursday. Given recent burn scars in the vicinity of the Los Angeles area, flash flooding will be a concern. Heavy rain and possible flooding will also extend downstream into the Sierra Nevada below roughly 8000 feet elevation, with locations higher than 8000 feet likely to receive very heavy snow. Campbell/Otto Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php