Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 336 AM EDT Sun Aug 11 2024 Valid 12Z Sun Aug 11 2024 - 12Z Tue Aug 13 2024 ...Scattered thunderstorms capable of containing locally heavy rainfall are forecast across much of the Southwest, Intermountain West, and Plains... ...Lingering flash flood potential exists across the coastal Carolinas over the next few days... ...Sultry summer heat returns to much of the Southern Plains and central Gulf Coast States this week... The weather pattern through early this week will feature daily chances for thunderstorms from the Southwest and Intermountain West into the Plains, as well as Florida and coastal sections of the Southeast. An upper level low in southeast Canada will also provide scattered precipitation chances to the Great Lakes and Northeast. Anomalous atmospheric moisture content throughout the Southwest and Great Basin when combined with shortwaves riding overtop of an upper ridge set up over the region will provide enough coverage of thunderstorms to support the potential for scattered flash flooding today from northwest Arizona to central Utah. Complex terrain and the sensitive slot canyon region of Utah increase the threat for flooding impacts. Additional chances for heavy rain extend to the southern California ranges and the remainder of the Southwest and Four Corners region over the next few days. Meanwhile, northwest flow aloft and nearby frontal boundaries will help aid thunderstorm development across the Great Plains. A few rounds of organized convection north of a warm front forecast to stretch from Oklahoma to the lower Mississippi Valley could lead to instances of flash flooding through tonight across parts of eastern Oklahoma, southeast Kansas, southwest Missouri, and northwest Arkansas. Localized downpours associated with thunderstorm activity are also possible throughout the remainder of the central and northern Plains today, with isolated severe storms a possibility for the central High Plains into the Black Hills region. This unsettled weather pattern is anticipated to remain in place early this week across the central United States. A lingering frontal boundary draped across the Southeast will provide a focus for additional thunderstorm activity over the next few days, overlapping with saturated ground conditions from last week's widespread heavy rainfall. As a result, localized downpours could result in additional flash flooding throughout the coastal Carolinas. Residents and visitors are reminded to avoid driving through flooded roadways and to not swim or play in floodwater. For much of the Nation, summer heat will be on hold to start the week as a cooler weather pattern takes shape compared to previous weeks. However, building heat will be felt throughout the southern Plains and Deep South as highs soar back into the upper 90s and triple digits by Monday. When combined with elevated humidity levels, afternoons will feel closer to heat index values of 110 degrees in the lower Mississippi Valley and immediate Gulf Coast. It is also worth noting that overnight temperatures will not offer much relief as lows only dip into the upper 70s and low 80s. This level of heat could affect anyone without effective cooling and/or hydration, so it is important to follow proper heat safety tips and check on vulnerable individuals. Elsewhere, poor air quality due to ongoing wildfires throughout the northern Great Basin is expected to continue. Upper level winds are forecast to carry smoke eastward over parts of the Midwest, Ohio Valley, and Mid-Atlantic, leading to hazy skies for some locations. Snell Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php