Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 407 PM EDT Wed Aug 07 2013 Valid 00Z Thu Aug 08 2013 - 00Z Sat Aug 10 2013 ***Warmer and more humid for the Eastern U.S.*** ***Heavy rainfall for the Central High Plains eastward into Ohio/Tennessee Valleys*** ***Heat wave over the Southern Plains*** High pressure sliding off the eastern seaboard will allow southerly flow to overtake most of the eastern U.S. over the next few days. An increasingly warm and humid airmass is expected to invade the region bringing a return to mid summer like weather to places that have seen below normal temperatures over the past few days. This marginally unstable airmass will support isolated to scattered afternoon convection, with more organized activity remaining along a slow moving frontal boundary further west. A quasi-stationary frontal boundary across the Central Plains will be the focus for stormy weather over the next few days. This boundary combined with weak shortwave energy exiting the southwest U.S. and a strengthening upper level jet across the Northern Plains will result in repeated rounds of convection along and mainly north of the surface boundary. The forcing large scale forcing for precipitation should remain in the same general area through the forecast period. Flash flooding will certainly be a concern across portions of Kansas eastward into the Mid Mississippi Valley into Friday. It will remain hot and humid over the Deep South states and into Texas, which are expected to remain south of the main frontal zone. The heat wave has prompted the issuance of widespread heat advisories and a few excessive heat warnings. Heat indices may approach 110 degrees in some of these areas with temperatures in the upper 90s to low 100s, along with high dewpoints. Krekeler/Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php