Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 341 AM EDT Sat Jul 09 2016 Valid 12Z Sat Jul 09 2016 - 12Z Mon Jul 11 2016 ... Severe thunderstorms across the northern High Plains through the weekend... ...Heavy rain and flash flooding possible for portions of central/southern Plains, middle Mississippi valley and Tennessee valley... ...Cool weather across the Northwest and hot and humid conditions over much of the central and eastern U.S... An upper-level low will move through the Pacific Northwest this weekend and send a cold front sweeping across the Intermountain West and into the northern Plains. Showers and high elevation snow are likely from the Cascades to the northern Rockies. Scattered showers and thunderstorms will develop ahead of the system east of the Northern Rockies. The Storm Prediction Center has much of the Dakotas and Minnesota under a slight risk through Monday morning. An enhanced risk on Sunday covers most of North Dakota and northwest Minnesota. Heavy rainfall may increase the threat for flash flooding along the Hi-Line Sunday into Monday. Hazy, hot, and humid conditions will persist across much of the southern tier of the nation and the East Coast this weekend. Widespread 90s for highs are forecast and lows in the 70s, and some areas have heat advisories in effect. Some triple digit temperatures are possible across parts of Texas, as well as the lower elevations of the Desert Southwest. A cold front will continue to move east through the Ohio valley/Mid-Atlantic region as the central low pressure lifts through the Northeast. Strong to severe thunderstorms will likely develop along and ahead of the boundary from the Ohio Valley and Deep South to locations to the east. Areas of heavy rain with the thunderstorm activity may lead to localized flash flooding. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php