Near record-breaking heat this week in Tucson will be followed with the first chance of monsoon rain, forecasters say.

A Heat Advisory is in effect for Memphis and all of the Mid-South from now until Friday at 9 p.m. CT.

WATCH: Heat, humidity, and rain continue to batter the Mid-South over the weekend ...

Climate and environment updates: AI-driven model could predict weather faster and more accurately: Expert The National Weather Service has begun testing of the model.