Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 254 AM EST Tue Nov 29 2016 Valid 12Z Tue Nov 29 2016 - 12Z Thu Dec 01 2016 ...There is a slight to enhanced risk of severe thunderstorms over parts of the Lower Mississippi and Tennessee Valleys... ...Heavy rain possible over the Lower Mississippi/Tennessee Valleys into Central/Southern Appalachians... ...Heavy snow possible over parts of the Upper Midwest... ...Heavy snow and winter mix possible over Northern New England... A deep and complex storm system will impact much of the central and eastern U.S. over the next few days. Two strong areas of upper-level energy will circulate around the storm's center. The first is associated with the cold front advancing through the Tennessee valley/Appalachians/Mid-Atlantic today and through the lower Great Lakes and Northeast by Wednesday; which is producing numerous showers and thunderstorms over the Lower Mississippi valley, Tennessee valley and portions of the southern Appalachians. Conditions will continue to be favorable for strong to severe thunderstorms across the Gulf states. Please refer to SPC products for additional information for severe weather. Heavy rain will be possible and may lead to flash flooding conditions in this region as well. Additionally, rain and freezing rain will develop over parts of Northern New England on this morning and will likely switch over to snow over Northern Maine this afternoon into Wednesday morning. The rain over the Upper Great Lakes/Ohio Valley will end by this afternoon. In addition, snow will develop over parts of the Northern Plains through Wednesday as colder air streams in around the low pressure center. Rain will continue over parts of the Northern Plains into the Upper Mississippi Valley also through Wednesday. The second area of upper-level energy will move from the Great Basin to the Southern Plains/Middle Mississippi Valley by Wednesday. Snow is expected to fall across portions of the Intermountain West through Wednesday morning. Showers and thunderstorms will develop along and ahead of the front associated with the second area of upper-level energy over the Lower Mississippi Valley on by this afternoon and will expand into the Tennessee Valley and Southern Ohio Valley by Wednesday. Rain will also return over parts of the Lower Great Lakes and Eastern Ohio Valley tonight into Wednesday. For the Pacific Northwest, a front will move inland and spread rain and mountain snow through Washington, Oregon and northern California tonight into Wednesday - before spreading east through the Intermountain West on midday Wednesday into Thursday Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php