A weather pattern favoring widespread rain with occasional heavy thunderstorms is setting up over the Tennessee Valley for the majority of this week. Tuesday is the day on which rain will be the most widespread and the most likely across the entire Valley. Rain can fall heavily at times, bringing a quick inch in less than an hour to localized areas. Heavy rain can also reduce visibility and make roads slippery. Remember to drive at slower speeds and be safe.
As far as timing goes... a few light showers are possible for the Tuesday morning drive. Those spotty showers will continue through the afternoon, leaving some dry spots. Then heavy rain will sweep from south to north across the Tennessee Valley Tuesday night from around 7 PM until around midnight. Where the heaviest rain falls, 1-3 inches of rain are possible. Rainfall amounts of a half-inch to an inch will be more common.
You may have a chance to get outside some during breaks between the showers. Be sure to get the grocery shopping done before 7 PM if possible. This heavy rain will mean slippery roads, dangerously low visibility, and occasional ponding of water on the roads.