Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 153 PM EST Sat Dec 07 2024 Valid 00Z Sun Dec 08 2024 - 00Z Tue Dec 10 2024 ...Heavy rain threat emerges across the Deep South late Sunday into Monday... ...Periods of mixed rain and snow linger from the Great Lakes to northern New England through the weekend... ...Unsettled and windy weather spreading across the Pacific Northwest this weekend will reach into the northern Plains as snow/wintry mix by Monday... ...Well above average temperatures across the Plains today will expand across much of the area east of the Rockies Sunday into Monday... The final hours of below average cold air will sweep away today into overnight across the South, Southeast and East Coast as the upper-level trough across the northeast is ushered away with one last quick moving clipper system traipsing through the Great Lakes today and into Interior New England through Saturday. Periods of mixed rain and snow are expected with the clipper, up to a foot of snow remains possible for parts near the Canadian boarder. On the other corner of the CONUS in the Pacific Northwest and Northern Rockies, unsettled weather ahead of a pair of cold fronts will trek across the area today into tonight bringing mixed precipitation with rains in the valleys and snows to the higher elevations. Snow levels will drop through the evening/overnight period into the northern Rockies behind the front and make for hazardous travel conditions. Winter Storm Warnings and Advisories are active across the Washington and northern Oregon Cascades and expanding eastward into the Northern Washington, Idaho and Western Montana. High Wind Warnings also accompany these winter conditions. By Sunday morning, a new surface cyclone will develop across the Southern Canadian Prairies and dive into North Dakota by late Sunday into Monday. Snows are likely along the Canadian border, but mixed precipiation may be more common across the Dakotas, central Minnesota into far Upper Lakes by early Monday. South of the area, the stronger southwesterly winds throughout the weekend ahead of the system well above average temperatures with highs in the 50-60s across the northern Plains into Midwest, some 15-25 degrees above normal, only diminishing a few degrees above normal by Monday over the Midwest/Great Lakes. Along the Gulf Coast/Lower Mississippi Valley, the tail end of the cold outbreak has seen a weak surface low develop in the western Gulf, ahead of an average positively tilted upper-level trough currently along the Mexican/Southwestern American border. Some weak cross Mexican flow will help increase mid-level moisture into Southeast Texas and Lower Mississippi River Valley and with warm/unstable air provided by the Gulf and forcing from the approaching trough aloft will help to develop showers and thunderstorm activity along/just off-shore today (Saturday) expanding across E Texas/Louisiana by Sunday evening across the Lower Mississippi and Delta Region into early Monday morning. The overlapping elements coupled with some recent rainfall, results in the possibility of scattered flash flooding becoming possible. The Weather Prediction Center has issued a Marginal Risk of Excessive Rainfall (level 1 of 4) from SE TX/SW LA Sunday up the Mississippi River to the KY/TN state lines. Gallina Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php