Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 319 AM EDT Mon Aug 13 2018 Valid 12Z Mon Aug 13 2018 - 12Z Wed Aug 15 2018 ...Heavy rain possible over parts of the Northern/Central Appalachians... ...Heavy rain possible over parts of the Central/Southern Plains and parts of the Middle/Lower Mississippi Valley... A quasi-stationary front extending from the Mid-Atlantic southward into the Southeast and the Eastern Gulf Coast will aid in producing showers and thunderstorms over the region through Tuesday evening. In addition, a quasi-stationary upper-level low over the Ohio Valley/Central Appalachians will slowly move eastward to the Northern Mid-Atlantic Coast by Tuesday evening. The energy will aid in producing showers and thunderstorms from parts of the Ohio Valley/Lower Great Lakes to the Northeast through Tuesday evening into Monday. The system will have slight diurnal component with the greatest areal coverage during the late afternoon into the late evening on Monday and Tuesday. Meanwhile, another area of upper-level energy over the Southern/Central High Plains and the Central/Southern Plains will slowly move northeastward to the Central Plains/Middle Mississippi Valley by Tuesday evening. The energy will aid in developing showers and thunderstorms over parts of the Southern/Central Plains into parts of the Lower Mississippi Valley. The showers and thunderstorms will expand into parts of the Tennessee Valley by Monday evening and into the Middle Mississippi Valley on Tuesday into Tuesday evening. Additionally, a front extending from the Northern Plains southwestward to parts of the Great Basin will move eastward to Upper Great Lakes/Middle Mississippi Valley westward to parts of the Great Basin by Tuesday evening. Showers and thunderstorms will develop along the boundary from parts of the Great Basin to the Northern Plains that will slowly move eastward to the Upper Great Lakes/Upper Mississippi Valley southwestward into parts of the Northern/Central Rockies by Tuesday morning. The showers and thunderstorms will move into the Upper Great Lakes/Middle Mississippi Valley by Tuesday evening. Elsewhere, weak monsoonal moisture and daytime heating will aid in producing showers and thunderstorms over parts of the Southwest/Great Basin and the Southern/Central Rockies through Monday. The showers and thunderstorms will have the greatest areal coverage during the late afternoon into the late evening on Monday and Tuesday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php