Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 PM EDT Tue Mar 21 2017 Valid 00Z Wed Mar 22 2017 - 00Z Fri Mar 24 2017 ...Rain and potential for thunderstorms across the western U.S.... ...Thunderstorms, potentially strong, across the mid Mississippi River Valley eastward across the Tennessee Valley and Mid Atlantic overnight... A cold front will be impacting the west coast over the next 24 hours, before dissipating by Wednesday evening. This will combine with yet another disturbance moving across the southwest, to bring widespread rain across much of the western U.S. over the next few days. Some of the highest terrain could see some snow mix in with the rain, while scattered thunderstorms will be possible across much of the southwest. A few thunderstorms may be strong across the Sacramento Valley and Northwest California this evening. Elsewhere, flood watches and warnings remain in effect for portions of the northwest, especially Idaho, as rain will combine with continued snow melt across the region. Meanwhile, another surface front oriented from west to east across the Lower Mississippi Valley, Tennessee Valley and Mid-Atlantic this evening will continue to slowly sag southward tonight and tomorrow, reaching the Gulf of Mexico and Florida by Thursday. The convergence of warm moist air from the Gulf of Mexico and colder air from Canada will be enough to spawn showers and thunderstorms, potentially strong, along and just north of this frontal boundary. The Storm Prediction Center has highlighted the middle Tennessee Valley into the southern Appalachians in an enhanced risk for severe thunderstorms through this evening. A slight risk for severe thunderstorms extends further into the Tennessee Valley and southern Appalachians as well. Please refer to the Storm Prediction Center website for more information (www.spc.ncep.noaa.gov). Elsewhere across the U.S., a low pressure system moving across the far northeast will lead to snowfall, mainly across Maine, over the next couple of days. An area of strong high pressure will span across much of the Midwest, Great Lakes, and Ohio Valley region over the next few days, resulting in dry and cool conditions. Wix Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php