The drier air from the last 5 days is coming to an end for the Tennessee Valley. Gulf of Mexico moisture returns with higher humidity this afternoon. Afternoon highs in the mid to upper 90s combined with the humidity will give the Valley heat index values in the triple digits. Heat index values at or above 105° are expected for areas closer to the Shoals which is why the NWS has issued a Heat Advisory for today.
Thunderstorm chances will increase each day through this workweek. Today only isolated thunderstorms are expected with best chances closer to Sand Mountain. Tuesday through Friday there will be better chances for widespread thunderstorms for the entire Valley each afternoon. Wednesday through Friday will likely be the wettest days of this week.