081 FXUS01 KWBC 061922 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 321 PM EDT Sun Sep 06 2026 Valid 00Z Mon Sep 07 2026 - 00Z Wed Sep 09 2026 ...Scattered strong to severe thunderstorms across the Southeast and Plains States for the remainder of the Labor Day weekend; Moderate Risk of Excessive Rainfall today in Iowa... ...Cool and unsettled weather will progress through the Great Basin and Intermountain West with heavy rain emerging across northwestern Montana on Labor Day, followed by strong thunderstorms across the Northern Plains Tuesday... ...Heat persists across the midsection of the country while cooler air expands further into the West Coast and the Northeast... A frontal boundary bisecting the Central and Southern U.S. continues to slowly press southward, and is expected to eventually stall as it encounters the heat dome anchored over the country's midsection. Behind the front, much of the Northeast and Mid-Atlantic can enjoy a break from the heat as high temperatures only reach into the mid-70s and low-80s for the next couple of afternoons. Morning lows dropping into the 40s and 50s will bring a first taste of Fall across New England. West of the boundary, showers and thunderstorms are on deck this afternoon as the leading edge of the front encounters a moist and unstable airmass on the periphery of the Plains heat dome. Isolated to scattered severe weather and heavy rainfall are possible this afternoon with any storms that develop across portions of the lower Mid-Atlantic, Southeast, and Central/Northern Plains. Within this broad area, however, a corridor of enhanced flash flooding potential has emerged over western Iowa as storms containing high rainfall rates focus over the area and lead to rainfall potentially in excess of 5". Accordingly, this area has been upgraded to a Moderate Risk of Excessive Rainfall today, and Flood Watches are in effect through late tonight. West of the Rockies, a deep upper-level low continues to edge farther inland across the western U.S. and support cool but unsettled weather today and tomorrow. Heavy rainfall remains possible today over southern Nevada and central Utah as strengthening southerly flow directs moisture originating from Hurricane Marie to the south toward a slow-moving front. Urban areas, as well as dry washes and burn scars will be most vulnerable to flooding. Over the next couple of days, a low-pressure system is forecast to gradually consolidate across the northern High Plains as the deep upper-low edges toward the Northern Rockies. The developing storm will interact with the anomalous moisture to yield an expansive shield of moderate to locally heavy rain on the northern flank of the low over the Northern Rockies. WPC is highlighting northwestern Montana for a Slight Risk of excessive rainfall on Labor Day. East of the wrap-around rainfall, an approaching Pacific cold front could drive strong thunderstorms across the Northern Plains, spreading eastward into the Upper Midwest, and southward into the Central Plains ahead of the trailing cold front on Tuesday as the maturing cyclone drifts across the Canadian Prairie. Temperatures beneath the upper-low will be cool across the West this weekend into the new week as daytime highs dip 10 to 25 degrees below normal. In fact, below-freezing morning temperatures are expected across the higher elevations as far south as northern California and the Sierra Nevada peaks. Meanwhile, oppressive heat will continue through Labor Day in the Nation's Heartland with the unrelenting upper-level ridge over the nation's midsection. Heat indices of 105 to 110 degrees and record warm overnight temperatures will be widespread across the Central/Southern Plains States and Mississippi Valley through Labor Day and into the work week. See WPC's Key Messages for more information on the heat, limit afternoon outdoor activity if possible, and stay hydrated regardless of your Labor Day plans. Asherman/Kong Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php Extreme Heat Key Messages available at: https://www.wpc.ncep.noaa.gov/key_messages/LatestKeyMessage_1.png $$