Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 300 PM EST Tue Dec 10 2024 Valid 00Z Wed Dec 11 2024 - 00Z Fri Dec 13 2024 ...Widespread heavy rain threat developing from the central and eastern Gulf Coast to the entire East Coast tonight into Wednesday... ...Arctic air to plunge south and eastward across the northern Plains, Upper Midwest, and Great Lakes tonight into Wednesday... ...Another round of significant lake effect snow to begin Wednesday and continue through Thursday downwind of the Lakes... A developing storm system over the Southeast U.S. is set to bring widespread heavy rains from the central and eastern Gulf Coast to the entire East Coast tonight into Wednesday. A wave of low pressure will rapidly strengthen and move northeastward across the interior Mid-Atlantic and Northeast, dragging a strong cold front along with it. Ahead of the front, warm and moist air will set the stage for numerous showers and thunderstorms, some of which could become strong to severe. This is especially the case across eastern North Carolina on Wednesday, where the Storm Prediction Center has issued a Slight Risk (level 2 of 5) for severe thunderstorms capable of producing damaging wind gusts. Elsewhere along the Eastern Seaboard, the main concern will be a period of heavy rain with embedded strong thunderstorms and intense downpours. Despite much of the region currently experiencing moderate to extreme drought conditions, the rain, while mostly beneficial, could still lead to some localized instances of flash flooding. The more urbanized locations and poor drainage areas would have the greater risk of flooding issues. The cold front will sweep across the East Coast Wednesday into Thursday, with much colder air surging in from the north and northwest in its wake. This Arctic blast will first plunge into the northern Plains and Upper Midwest tonight before expanding eastward across the Great Lakes, Mid-Atlantic and Northeast Wednesday and Thursday. High temperatures the next couple of days will be roughly 10 to as much as 30 degrees below normal. The cold post-frontal air mass will also help to change rain to snow across the western slopes of the Appalachians and interior portions of New England and the Northeast with at least modest accumulations looking like a decent bet. Attention then turns to yet another round of significant lake effect snow downwind of the Great Lakes Wednesday through Thursday. The aforementioned Arctic air will stream across the still relatively warm Great Lakes and ignite intense bands of lake effect snow, initially downwind of Lakes Superior and Michigan on Wednesday and then downwind of Lakes Erie and Ontario Wednesday night into early Thursday. By the time the snow starts to taper off on Friday, snowfall totals of 1 to 2 feet are likely in the favored Snow Belt across portions of northwest and western New York State, far northwest Pennsylvania, far northeastern Ohio, the Upper Peninsula of Michigan and the western portions of the Lower Peninsula of Michigan. Miller Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php