Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 412 AM EDT Tue Jun 19 2018 Valid 12Z Tue Jun 19 2018 - 12Z Thu Jun 21 2018 ...Flash flooding and strong thunderstorms expected for Central Plains to Ohio Valley and Mid-Atlantic... ...Heavy rain and flash flooding forecast along and near the Texas coast... ...Heat continues for the Middle Mississippi Valley to Mid-Atlantic and Carolinas... A frontal system remains stalled over the Central Plains through the Middle Mississippi Valley, Ohio Valley, and Mid-Atlantic, which will continue to produce multiple rounds of rain and thunderstorms along it on Tuesday and Wednesday. As an upper-level low provides additional support for thunderstorm development, storms are expected to become more widespread and organized in the Central Plains on Tuesday and Tuesday night. Storms could be severe, and a moderate risk of excessive rainfall/flash flooding is in effect as well. Severe weather and locally heavy rain and flash flooding are also possible east of there along the front, with slight risks of flash flooding on Tuesday and Wednesday and a marginal risk of severe weather on Tuesday. Farther south, summertime scattered storms are forecast south of the front for the Lower Mississippi and Tennessee Valleys and the Southeast, but widespread severe weather and flash flooding are not expected there. And farther west, showers and thunderstorms will persist on Tuesday for the Northern Rockies and Northern Plains, with locally heavy rain possible and cooler than average temperatures. A trough of low pressure as well as high moisture levels will lead to more rain for southern and southeastern Texas for the middle of the week. As several inches of rain is expected, and because portions of this region have seen heavy rain overnight already, moderate risks of flash flooding are in effect on Tuesday and Wednesday. Another day of hot weather is forecast south of the front on Tuesday, with above average temperatures from the Middle Mississippi Valley to the Mid-Atlantic and Carolinas. Heat Advisories are in effect for the eastern Carolinas and southeastern Virginia, and linger across portions of Missouri and Illinois, with Excessive Heat Warnings in place for the St. Louis area. Temperatures are expected to cool some on Wednesday as clouds increase due to the front. Heat also builds into the West by Wednesday, with a few record highs possible in the Pacific Northwest. Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php