Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 255 AM EDT Thu Aug 21 2025 Valid 12Z Thu Aug 21 2025 - 12Z Sat Aug 23 2025 ...Tropical Storm conditions continue for the North Carolina Outer Banks and coastal Virginia Thursday; tropical storm force gusts possible for the remainder of the Mid-Atlantic and southern New England Coasts through early Friday... ...Life-threatening surf and rip currents will be churning up and down the East Coast through the next couple of days... ...Thunderstorms expected along a stalling cold front across portions of the Southeast, Gulf Coast, and Texas, with a Slight Risk of Excessive Rainfall for portions of Georgia and South Carolina Friday... ...Dangerous heat wave building over the western U.S. late this week and into the weekend... Hurricane Erin, with its expanding circulation, will continue to bring impacts to portions of the East Coast as it churns offshore to the east. Tropical storm conditions will remain possible along the North Carolina Outer Banks and expand northward along the Virginia Coast Thursday. Wind gusts to tropical storm force are also likely further north along the remainder of the Mid-Atlantic Coast, and along the coast of southern New England Thursday through early Friday. Storm surge flooding will also continue along the North Carolina Outer Banks through Thursday, with large waves leading to significant beach erosion and overwash, and some roads may become impassible. In addition, life-threatening surf and rip currents remain a serious concern more broadly along the East Coast and will likely last through at least the next couple of days. Beachgoers should follow advice from lifeguards, local authorities, and beach warning flags. Scattered thunderstorms are expected ahead of a slow moving cold front draped across the southeastern to south-central U.S. Plentiful moisture and slow-moving, clustering storms in vicinity of the boundary will bring the threat of locally heavy rainfall and isolated flash flooding from the southern Appalachians southwest along the Gulf Coast and west into eastern/central Texas. The front will become quasi-stationary into Friday, with another round of thunderstorms anticipated across the southern Appalachians, southwest through South Carolina/Georgia and along the Gulf Coast. Additional instances of isolated flash flooding can be expected. A more focused corridor of pooling moisture and convergence along the boundary through portions of central/southern Georgia east into coastal South Carolina has prompted a Slight Risk of Excessive Rainfall (level 2/4) for more scattered instances of flash flooding. Further west, elevated monsoonal moisture will continue to trigger afternoon thunderstorms across portions of the Southwest/Four Corners region Thursday and expand into the central Rockies Friday. Locally intense downpours could produce a quick 1-2" of rain which may lead to some isolated flash flooding, particularly for more sensitive areas such as along steep terrain, burn scars, and urban areas. Elsewhere, an upper-level low and accompanying surface cold front will trigger thunderstorms across portions of the Upper Midwest west through the northern High Plains Thursday. Some locally heavy downpours and isolated flash flooding will be possible across the Upper Midwest. The front will progress a bit eastward and southward on Friday, with storm chances spreading into the Upper Great Lakes while continuing for the Upper Midwest west through the northern High Plains. Dangerous heat is expected to intensify and expand in coverage over much of the western U.S. the next couple of days and continue into the weekend under the influence of a strong upper-level high. Widespread heat-related warnings and advisories are in effect across much of inland California/Oregon and Nevada as highs climb into the 90s and 100s, and across the Desert Southwest as highs climb into the 110s. This dangerous level of heat will pose a threat to anyone without effective cooling and adequate hydration. Highs into the 90s more broadly across the West will still pose a threat to anyone more sensitive to heat or engaging in strenuous outdoor activities. Elsewhere, another day of hot, above average conditions into the 90s is expected Thursday across much of the northern/central Plains. A cold front will bring cooler, below average conditions mainly in the 70s southward on Friday. The cold front passage across the eastern to south-central U.S. has left generally seasonable conditions for the next couple of days, with 90s across the Southeast to Southern Plains, 80s for the Midwest, and 70s into the Upper Great Lakes. Conditions will remain well below average Thursday for much of the Northeast, with highs in the 70s, before more seasonable highs into the 80s return Friday. Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php