Cool Air is marching South and running into moist warm air. Where they collide, storms will pop up. That will happen from the South to New England on Saturday.
By Sunday night, the leading edge of the cool air reaches South Florida but it will arrive extremely weak. It will cause a few showers Sunday evening. What the front will do is get rid of the high humidity levels. Monday will see near typical highs in the mid 80s but with low humidity readings it will feel great for a day or two. Welcome to Fall, Florida style.