A medium to high chance of showers and thunderstorms, decreasing to a slight to medium chance in the southern Simpson and Lasseter Districts. Possible heavy falls with showers and thunderstorms for locations both south of Tennant Creek and north of Alice Springs. Light to moderate west to northwesterly winds ahead of a southerly change moving north from the southern border to Barrow Creek during the afternoon and evening. Winds fresh and gusty in the southern Simpson District at times.