Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 307 PM EDT Fri Aug 30 2024 Valid 00Z Sat Aug 31 2024 - 00Z Mon Sep 02 2024 ...Heavy rain and severe weather chances will spread from the Plains to East Coast to start the holiday weekend... ...Multiple days of heavy rain may cause flash flooding for portions of the Louisiana and Texas Gulf Coasts... ...Well above normal temperatures forecast in the northwestern U.S. this weekend... Two frontal systems are forecast to move south across the central and eastern U.S. over the holiday weekend, bringing widespread showers and thunderstorms from the central and southern Plains through the Mississippi Valley to the East Coast. Severe thunderstorms will be possible in the warm sector ahead of the leading cold front where there will be ample moisture and instability. The Storm Prediction Center has issued a Slight Risk of severe thunderstorms (level 2/5) for eastern Michigan today and for portions of the Northeast, Mid-Atlantic, and central Appalachians Saturday. Damaging wind gusts will be the main severe thunderstorm threat. Additionally, showers and storms will be capable of producing locally heavy rainfall that could lead to isolated instances of flash flooding from the southern Plains to the Northeast. The leading front is forecast to stall across the South and Southeast later this weekend, producing widespread showers and storms through Labor Day. The second cold frontal passage will be mostly dry with the exception of some light showers near the Great Lakes and Northeast Saturday and Sunday, respectively. The second front is forecast to slow down as it approaches the stalled front across the southern tier. Along the Gulf Coast, an area of low pressure will linger just offshore of Texas and Louisiana. This system will continue to bring a concentrated area of heavy rain and thunderstorms to portions of the Louisiana and upper Texas Gulf Coasts through the weekend. High rain rates and repeating rounds of storms may lead to scattered instances of flash flooding, especially in urban and flood prone areas. This area has been highlighted with a Slight Risk of Excessive Rainfall (level 2/4) for today and Saturday. Daily thunderstorm chances will also exist over portions of the Florida Peninsula. Temperatures across much of the East will generally be cooling down as precipitation chances increase ahead of the approaching frontal systems, which will bring an end to the period of record setting heat that impacted the region this week. The central U.S. will see temperatures fall below normal this weekend in the wake of the cold fronts. Highs in the southern Plains will stay in the 80s and lower 90s. Highs in the northern/central Plains will drop from the 80s to near 90 degrees on Saturday to the 70s on Sunday. In the West, temperatures will be heating up in the Northwest as an upper level ridge builds overhead. High temperatures are forecast to be 10-20 degrees above normal, reaching the mid-to-upper 90s to near 100 degrees in some areas. Heat Advisories have been issued for much of eastern Washington and Oregon and northern Idaho. Those with outdoor plans for Labor Day weekend should be sure to take frequent breaks from the heat in the shade and stay hydrated. Elsewhere in the West, temperatures will generally be near or just above average. Dolan Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php