Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 351 AM EDT Tue Aug 13 2024 Valid 12Z Tue Aug 13 2024 - 12Z Thu Aug 15 2024 ...Heavy rain and flash flooding threat forecast to stretch from the central Plains to the Midwest over the next few days... ...Potentially dangerous heat anticipated across the southern Plains, lower Mississippi Valley, and Gulf Coast... ...Fire weather concerns and poor air quality continues for portions of the Pacific Northwest, Northern Rockies, and Great Basin... A mid-August weather pattern continues to take shape this week with numerous areas of scattered thunderstorms impacting the Nation. A stationary front currently stretching from the Southeast to the central High Plains will be the focus for much of this activity, with the boundary eventually forecast to lift north into the Midwest by Wednesday night due to a deepening low pressure system in the central Plains. The most likely weather hazard over the next few days with developing thunderstorms is expected to be associated with heavy rainfall creating instances of flash flooding, as well as the potential for isolated areas of damaging wind gusts. Specifically, three separate areas along the front stand out today as having the greatest chances for scattered flash floods. Parts of South Carolina remain sensitive to locally heavy rain as the area continues to contain saturated ground conditions, leading to a continued threat for flash flooding as long as the atmosphere supports slow-moving thunderstorms. For much of eastern Kansas and Missouri, an initial complex of thunderstorms is forecast to move through the region this morning containing locally heavy rainfall, while a reforming area of convection overnight into Wednesday could create additional flooding concerns. This second round of heavy rain has the potential to produce a narrow corridor of impressive rainfall totals within a few hours near south-central Missouri. Additionally, northeast Colorado can expect another round of storms containing intense rainfall rates this evening as activity forms along the leeward side of the Rockies and pushes eastward. Residents and visitors are advised to have multiple ways of receiving warnings, have a plan should flash flooding occur, and never drive through flooded roadways. By midweek much of the heavy rain and thunderstorm activity is anticipated to gradually shift eastward to the Midwest and lower Ohio Valley, along with the strengthening low pressure system and lifting warm front. Once again heavy rain will be a concern as ample atmospheric moisture content creates ripe conditions for scattered vigorous downpours. Dangerous summer heat will be confined to the southern U.S. this week as highs into the upper 90s and triple digits span from the Southwest to the Gulf Coast. The most anomalous and potentially dangerous heat is forecast across the southern Plains and Gulf Coast States through the end of the week as highs reach up to 10 degrees above the climatological average for mid-August. Elevated humidity levels will lead to maximum heat indices up to 110 degrees during the day and low temperatures only dipping into the upper 70s and low 80s at night. People spending greater time or effort outdoors, or in a building without effective cooling, are at an increased risk of heat-related illnesses. A persistent pattern supporting fire weather concerns across much of the central and northern Great Basin is forecast to continue today with dry terrain and periods of gusty winds. Red Flag Warnings remain in place from eastern Oregon to Idaho. Ongoing wildfires also continue to spread smoke into the atmosphere, leading to poor air quality. Snell Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php