Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 338 AM EDT Tue Aug 14 2018 Valid 12Z Tue Aug 14 2018 - 12Z Thu Aug 16 2018 ...Heavy rain possible over parts of the Middle/Lower Mississippi Valley... A quasi-stationary front extending from parts of the Northeast southward across coastal parts of the Mid-Atlantic into parts of the Southeast will slowly dissipate by Wednesday morning. Showers and thunderstorms will develop along parts of the Mid-Atlantic Coast into the Southeast and Eastern Gulf Coast through Wednesday evening. In addition, an upper-level low over the Northern Mid-Atlantic/Northern Appalachians will slowly move northeastward off the Northeast Coast by Wednesday evening. The energy will aid in producing showers and thunderstorms over parts of the Lower Great Lakes/Northeast and parts of the Northern Mid-Atlantic that will move off the Northeast Coast by Wednesday morning. The showers and thunderstorms will have the greatest areal coverage during the late afternoon into the late evening on Tuesday. Meanwhile, another upper-level low over the Central Plains will slowly move eastward to the Middle Mississippi Valley while weakening by Wednesday evening. The energy will trigger showers and thunderstorms over parts of the Central/Southern Plains into parts of the Middle/Lower Mississippi Valley that will likewise move eastward into parts of the Ohio Valley and parts of the Middle Mississippi Valley by Wednesday evening into Thursday. Additionally, a front extending from the Upper Great Lakes/Upper Mississippi Valley westward to the Great Basin will move eastward to the into parts of Northern New England across the Great Lakes then southwestward to the Central Plains by Wednesday evening. Showers and thunderstorms will develop along the boundary from parts of the Upper Mississippi Valley/Northern Plains into parts of the Northern Rockies that will move eastward to the Northeast/Great lakes into parts of the Northern Plains by Wednesday evening into Thursday. Elsewhere, weak monsoonal moisture and daytime heating will aid in producing showers and thunderstorms over parts of the Southwest/Great Basin into parts of the Central/Southern Rockies through Wednesday evening. The showers and thunderstorms will have the greatest areal coverage during the late afternoon into the late evening on Tuesday and Wednesday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php