Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Thu Aug 17 2017 Valid 12Z Thu Aug 17 2017 - 12Z Sat Aug 19 2017 ...There is a slight risk of severe thunderstorms over parts of the Great Lakes/Ohio Valley... ...There is a slight risk of severe thunderstorms over parts of the Southern High Plains... ...Heavy rain possible over parts of the Southern Plains/Lower Mississippi Valley... ...Heavy rain possible over parts of the Carolinas... A storm over the Upper Mississippi Valley will lift northeastward to Eastern Ontario while the associated front moves from the Upper/Middle Mississippi Valley/Southern High Plains to Northern Appalachians/Mid-Atlantic and the Southeast/Lower Mississippi Valley by Friday evening. The system will produce showers and thunderstorms from Upper Mississippi Valley/Great Lakes/Ohio Valley to the Middle/Lower Mississippi Valley and the Southern Plains that will move eastward to the Northeast/Mid-Atlantic into the Central/Southern Appalachians and the Central Gulf Coast by Friday evening. In addition, moisture rich air and daytime heating over the Southeast into parts of the Mid-Atlantic will aid in producing showers and thunderstorms over the area on Thursday and Friday afternoon and evening. Meanwhile, upper-level energy will coalesces over the Northern Plains overnight Thursday moving to the Middle/Upper Mississippi Valley by Friday evening. The energy will produce showers and thunderstorms over parts of the Plains by Thursday evening that will move eastward to the Upper/Middle Mississippi Valley and the Southern Plains by Friday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php