Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 253 PM EDT Mon Sep 09 2019 Valid 00Z Tue Sep 10 2019 - 00Z Thu Sep 12 2019 ...Threats for severe thunderstorms and flash flooding will focus from the Upper Midwest westward into portions of the Great Plains through Wednesday... ...Late summer heat will linger across the Southeast while spreading north and east through Wednesday... ...Below average daytime high temperatures from the Northern Plains into much of the West to persist through mid-week... The upper level pattern across the U.S. will not deviate much from its current state with troughing out West and ridging across the Southeastern U.S. into the middle of the week. This means that there will be only minor changes in the large scale weather affecting the nation over the next couple of days. Severe thunderstorms and flash flooding will be possible late this afternoon for parts of Iowa, Minnesota and Wisconsin into the early overnight hours near a warm front out ahead of an advancing low forecast to move through South Dakota tonight. A cold front in the wake of the low center will not advance too far south and will in fact return north as a warm front for Tuesday into Nebraska and South Dakota. Severe thunderstorms will again be possible on Tuesday and Wednesday near the front across the Great Plains while threats of flash flooding also focus near and north of the severe threat. The western end of the cold front will move through the Great Basin keeping unsettled conditions in place behind the front. In addition, from North Dakota into the western U.S., daytime highs will be about 10-20 degrees below average through Wednesday. Meanwhile, ongoing heat across parts of the Southeast will spread north and east into the middle of the week as a weak front dissipates and return flow around a surface ridge advects warmer temperatures and humidity into the Great Lakes and Northeast. Expect high temperatures generally from the mid-80s to mid-90s across a large portion from the nation's Heartland into the eastern U.S. by Wednesday. Otto Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php