An upper level low will be dropping south into the Four States region over the weekend and will help to bring a weak cold frontal boundary into the area Saturday night into Sunday. With the front in the area and the assistance of late August sunshine, widely scattered showers and a few thunderstorms will develop mainly during the mid to late afternoon hours with continuation into the evening. With the loss of heating, the thunderstorms should weaken and dissipate leaving skies partly cloudy overnight. The front will move just south of the Missouri and Arkansas border by daybreak Sunday but will still be close enough to the area to help the formation of isolated showers and thunderstorms over extreme Southern Missouri, Northeast Oklahoma and Northwest Arkansas; again mainly during the afternoon hours. Temperatures will be near normal for late August with highs in the upper 80s and lower 90s and lows in the middle and upper 60s.