Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 433 AM EDT Sun Jul 29 2018 Valid 12Z Sun Jul 29 2018 - 12Z Tue Jul 31 2018 ...Severe thunderstorms and/or heavy rainfall possible across portions of the central Plains on Sunday, shifting eastward into the Mississippi Valley by Monday.. ...Dangerous heat expected for portions of the West and Southwest... Widespread showers and thunderstorm are expected across the central U.S. as an upper level system digs southward across the central Plains today and into the Mississippi Valley by Monday. A moist and unstable airmass in place will allow for an environment favorable for severe weather and heavy to excessive rainfall, particularly along a surface cold front as it moves slowly south and eastward through the central/southern Plains, with a trailing portion banked up against the Colorado Rockies. For Sunday, both the Storm Prediction Center and WPC have marginal to slight risks highlighted from Oklahoma/Kansas and back into the central High Plains. On Monday, heavy rainfall again becomes a concern along the frontal boundary from the lower Ohio Valley to the southern Plains, where WPC has a marginal to slight risk for flash flooding on the day 2 excessive rainfall outlook. Please refer to the outlooks by these centers for additional information. To the east, a lingering front will keep showers and thunderstorms in the forecast the next couple of days across much of the Southeast and Deep South. The best chance for heavy to locally excessive rains will be across the eastern Carolinas as tropical moisture interacts with the stalled boundary. Unsettled weather returns to the Mid-Atlantic and Appalachians by Monday as this boundary begins lifting northward and the previously mentioned upper level system approaches from the west. Meanwhile, a dangerous heat wave remains ongoing across parts of the Southwest and California, and will begin building northward into the Northwestern states on Sunday and Monday. Numerous excessive heat warnings, watches, and advisories are in effect for portions of interior California, and the Northwest. Afternoon high temperatures across this region are forecast to be in the upper 90s to low 100s, which is as much as 10 to 15 degrees above normal. Expect little relief from the heat overnight as well with daily high minimum records possible up and down the West Coast. The hot and dry conditions, combined with locally gusty winds, will also increase fire weather threats and exacerbate ongoing fire activity across the Western states, with poor air quality a concern as well. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php