Arkansas has a surprising number of cities that we can drop forecasts for. The Northwestern Arkansas corridor is definitely more lively than one would normally be lead to believe.

At 953PM, CT, Fayetteville was reporting a temperature of 79 degrees with clear skies and dew points also parked in the upper 70s. It is a surely uncomfortable night which will see some haze across the region by morning. There are heat advisories out across the region, except in the Fayetteville area, where terrain and foliage will help blunt the high temperatures.
Low pressure in the Hudson Bay area is the only particularly well organized system in North America, and it is dangling a generally ineffectual boundary through the heart of the country. It is peeling back dew points a bit, and promoting a moist flow through the Lower Mississippi Valley northward, and will continue to do that through the day Sunday. The weak boundary will arrive in town by evening, and may lead to a more comfortable Monday, with isolated thunderstorms a distinct possibility throughout the day on Monday, but also in the evening on Sunday.
Tomorrow – Partly cloudy, afternoon thunderstorms. Humid. High 92, Low 73
Monday – Mostly cloudy, scattered showers and storms, High 89, Low 70

TWC: Tomorrow – Scattered thunderstorms in the morning, then partly cloudy late High 92, Low 72
Monday – Partly to mostly cloudy. A stray shower or thunderstorm is possible. High 91, Low 71

AW: Tomorrow – Sun and some clouds with a thunderstorm in spots in the afternoon High 92, Low 73
Monday – Humid with more clouds than sun; an afternoon thunderstorm High 91, Low 72

NWS: Tomorrow – A 30 percent chance of showers and thunderstorms, mainly before 1pm. Partly sunny, High 93, Low 73
Monday – A 40 percent chance of showers and thunderstorms. Partly sunny, High 92, Low 72

WB: Tomorrow – Mostly cloudy with chance of showers and thunderstorms in the morning then partly cloudy with slight chance of showers and thunderstorms in the evening. High 90, Low 75
Monday – Partly cloudy with a 50% chance of showers and thunderstorms, High 89, Low 74

WN: Tomorrow – Partly cloudy with a chance of storms, High 93, Low 72
Monday – Partly cloudy with a chance of storms, High 92, Low 71

FIO: Tomorrow – Humid and partly cloudy throughout the day. High 92, Low 73
Monday – Humid and partly cloudy throughout the day. High 89, Low 72

Here is the satellite for the evening, which just shows how clear the skies are to night in the south central US.