The highest risk is expected from Aug. 19-21 across parts of the central and southern Plains, Mississippi Valley, and Southeast, according to the National Weather Service’s Climate Prediction Center. The threat includes portions of Texas, Oklahoma, Kansas, Missouri, Arkansas, Louisiana, Mississippi, Tennessee, Alabama, Georgia, and the Carolinas, according to the National Oceanic and Atmospheric Administration (NOAA) outlook map.
An elevated risk continues through Aug. 22, extending into parts of the Tennessee Valley and southern mid-Atlantic. Unusually hot conditions could persist through Aug. 25 across the wider region, including parts of Florida and Virginia.
Heat indexes may exceed 110 degrees in the hardest-hit areas from Aug. 19-21. Some locations could experience feels-like temperatures above 105 degrees for several days.
Forecasters are also concerned about nighttime heat. Low temperatures could approach or break daily records, giving people without reliable air conditioning little opportunity to recover after dangerously hot days.
“More than 700 people die from extreme heat every year in the United States,” the CDC states. Heat stroke can cause confusion, loss of consciousness, and seizures.
Arkansas is expected to endure an especially severe stretch. The National Weather Service office in Little Rock said temperatures would rise through the weekend, with highs in the 90s and low 100s continuing into the following week. Extreme Heat Warnings and Heat Advisories covered parts of the state Wednesday.
The extended heat could also rapidly deepen drought conditions. NOAA identified a rapid-onset drought risk across parts of the central and southern Plains and the middle and lower Mississippi Valley, where some areas have received at least 2 inches less rain than normal during the past 30 days.
Meanwhile, heavy rain could bring flash flooding from the Desert Southwest and Rockies into the Plains and upper Mississippi Valley from Aug. 20-22, especially near canyons and dry creek beds.