Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 406 AM EDT Fri Aug 31 2018 Valid 12Z Fri Aug 31 2018 - 12Z 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 north-central portions of the U.S. will be in an active wet pattern into the weekend as a multiple fronts move through the Northern Plains and Upper Mississippi Valley/Upper Midwest. Showers and thunderstorms are expected to focus along and north of a warm front lifting through Iowa into Minnesota and Wisconsin, with storm motion likely tracking over the same area. This, in combination with higher rainfall rates, will elevate the risk for flooding concerns. With recent heavy rainfall, minimal additional amounts will be needed to aggravate ongoing flooding. These storms may be capable of producing flash flooding--which is highlighted by WPC's excessive rainfall outlook with a slight risk. Additionally, severe thunderstorms may develop over this corridor cold front sweeps through the Northern Plains into the Upper Midwest. The Storm Prediction Center has much of the Middle and Upper Mississippi Valley highlighted in a slight risk. Another cluster of thunderstorms will move across the Upper/Middle Mississippi Valley and portions of the Ohio Valley on Saturday. Once the front stalls across the Great Lakes and into the central Plains, scattered showers and thunderstorms can be expected along the front. A cooler and less muggy airmass will filter into the Northeast and Mid-Atlantic regions as a cold front moves in and then stalls. This boundary will act as a focus for continuous rounds of showers and thunderstorms over the next few days 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. Much of the West remain in critical fire weather as the hot and dry airmass remains in places. Dry thunderstorms along with strong, gusty winds will maintain elevated concerns for wildfire spread. Although there will be a slight improve in the amount of smoke present across southern Oregon, Air Quality will still be compromised over the next couple of days. 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. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php