Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 420 AM EDT Sun Aug 4 2013 Valid 12Z Sun Aug 4 2013 - 12Z Tue Aug 6 2013 ***High quality airmass for the Eastern U.S.*** ***Stormy weather for the Central Plains and into Missouri*** ***Scattered showers and storms over the Intermountain West*** A cold front approaching the East Coast will bring a high quality airmass to much of the Eastern U.S. for Sunday through Tuesday. This surface high from Canada will bring a refreshing change to the weather, with much lower humidity and highs mainly in the 70s and lower 80s. South of the cold front, it will remain hot and humid over the Deep South states and Florida, and scattered showers and storms can be expected near the frontal boundary and to the south of it. A nearly stationary frontal boundary over the western High Plains will provide a focus for widespread showers and storms this weekend from the Dakotas southward to northern Texas. Given the abundance of moisture and instability across the area, flash flooding and isolated severe weather is not out of the realm of possibilities as thunderstorm complexes are expected to develop. Elsewhere, isolated to scattered convection can be expected each afternoon over the Four Corners region with the monsoonal moisture in place, and a few showers are also possible across interior parts of the Pacific Northwest on Sunday. Another cold front is forecast to approach the northern High Plains by the end of the forecast period, with more cool weather behind it. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php