Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 409 PM EDT Thu Aug 30 2018 Valid 00Z Fri Aug 31 2018 - 00Z Sun Sep 02 2018 ...Heavy rain and severe weather possible for the Mississippi Valley through Saturday... ...Heat wave coming to an end along the East Coast.... ...Fire weather concerns across the West... The Mississippi Valley and northern/central Plains will experience an active weather pattern moving into the holiday weekend. By later tonight and into early Friday morning, a cluster of thunderstorms will form along the warm front draped across the middle Mississippi Valley and move southward across southwest Iowa and Missouri. These storms may be capable of producing flash flooding--which is highlighted by WPC's excessive rainfall outlook with a slight risk. The severe weather risk will remain marginal. On Friday, a cold front will move from the northern into the Upper Midwest. Heavy rainfall especially along the surface low can be expected--mostly across Minnesota. A slight risk of thunderstorms will also be possible especially in the Mississippi Valley and northern/central Plains. From late Friday night and into early Saturday morning, as the front continues moving south and stalls, another cluster of thunderstorms will move across the upper/middle Mississippi Valley and portions of the Ohio Valley. Once the front stalls across the Great Lakes and into the central Plains, scattered showers and thunderstorms can be expected along the front. The heat wave that has plagued the eastern and southern U.S. will be coming to an end today especially for the Mid-Atlantic and Northeast. A cold front has pushed along New England and Northeast and will stall in the Mid-Atlantic. Continuous rounds of showers and thunderstorms over the next few days can be expected for the Mid-Atlantic, Tennessee Valley, and Southeast. This activity will assist in keeping the high temperatures much cooler than what has been recorded this week especially for the Mid-Atlantic. Fire weather concerns will be critical today across the West. Due to a combination of warm temperatures, low humidities and gusty winds, red flag warnings are in effect for most of Wyoming, northwest Colorado, portions of Utah and extreme southwest South Dakota. Furthermore, the southern Foot Hills in South Dakota have critical fire weather conditions and are under extreme fire danger for today. Additionally, air quality issues remain for southwest Oregon from nearby wildfires. This region is under an Air Quality Alert issued until further notice. Elsewhere, subtropical moisture will aid in diurnally driven thunderstorms across the Gulf Coast through Saturday--with heavy rainfall particularly expected for parts of the central Gulf Coast on Saturday. Reinhart Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php