Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 236 AM EST Mon Nov 28 2016 Valid 12Z Mon Nov 28 2016 - 12Z Wed Nov 30 2016 ...Heavy rainfall and severe weather possible across portions of the Lower Mississippi Valley and Deep South... ...Heavy snowfall possible across the higher terrain of the Intermountain West and into the Northern Plains Monday and Tuesday... Widespread showers and thunderstorms are expected along and ahead of a frontal boundary as it moves through the Mississippi Valley today and into the Ohio Valley and Eastern seaboard states by Tuesday. The heaviest rainfall is expected across portions of the Lower Mississippi Valley into the Tennessee Valley on Monday and again on Tuesday into Wednesday as the southern portion of the boundary stalls and a second system approaches from behind. WPC is highlighting a marginal to slight risk for excessive rainfall across these regions on both days. In addition to the heavy rainfall, plenty of instability along and ahead of the boundary will allow for organized strong to severe thunderstorms across the same area, with the Storm Prediction Center forecasting an enhanced risk on Monday, and slight risks Tuesday into Wednesday from eastern Texas to Alabama. Cold air and upper level dynamics on the backside of the surface low in the Upper Midwest from this initial system will allow for heavy snowfall across portions of the Northern Plains on Monday. A second system on its heels however keeps the threat for heavy snowfall across not only the Northern Plains but also much of the interior West and Rockies through Wednesday. Winter storm warnings, watches, and winter weather advisories are in effect across much of the Northern Plains as well as the higher elevations of the Rockies and Intermountain West. Gusty winds across the entire region are also expected to create blowing snow and hazardous travel conditions. As one storm exits the mountains, another makes its way onshore across the Pacific Northwest. Another round of rain and higher elevation snow is possible across much of the Northwest by Wednesday. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php