Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 358 PM EDT Fri Oct 23 2015 Valid 00Z Sat Oct 24 2015 - 00Z Mon Oct 26 2015 ...Heavy rain and flash flooding will continue throughout the Southern Plains and portions of the Mississippi Valley... Multiple upper-level trough/ridge pairings will be driving the weather over the USA through the weekend. Shortwave disturbances will move through the most prominent upper-trough, which is currently positioned over Nunavut, Canada to the Desert Southwest, resulting in a series of cold fronts pushing through the northern tier of the US. Scattered to widespread showers will develop along and ahead of these fronts -- amounts will mainly be less than 1 inch across the Upper Midwest, Ohio Valley and the Northeast through Saturday night. Lake Superior and the surrounding areas are forecast to have around 1.5 inches. Temperatures will be favorable for mixed precipitation to occur over northern Minnesota and northeast North Dakota Saturday night through early Monday morning. The frontal system associated with the southern end of the the upper-level trough will continue to spread across central and eastern U.S. through the weekend. The northern flank of the cold front will have mostly pushed offshore by Sunday night and shower activity will be on the light side. The southern flank will slow its progression over the southern states. Meanwhile, plumes of very moist air will persist in transporting from the Gulf of Mexico into the Plains. This abundant moisture in conjunction with the slow moving thermal boundary drive widespread convection over the next few days. Most of this convection will occur from central to north Texas. As the axis of the upper level low centers over the Big Bend region of Texas, this will drive the main cold front to move from the central Plains on Friday toward the Texas coastline throughout Saturday and into Sunday morning. This will shift the heaviest axis of rainfall south and eastward along the coast of Texas. Given that this will be a multi-day event and will likely drop a significant amount of rain, flash flooding will be a major concern. See both WPC's excessive rainfall forecasts and QPF for further information. Campbell/Fanning Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php