A rainy pattern that has brought between five and seven inches of rain to the Tennessee Valley since last Friday will be capped off with a risk for destructive severe thunderstorms Saturday evening. This system will finally cause a large-scale weather pattern shift that will give us a chance to dry out, but it doesn't happen without some fanfare.
More Heavy Rain On Friday
First we have to get through another rain-filled day on Friday. Widespread rain can fall heavily at times. That heavy rain will reduce visibility and leave ponding of water on our roads. More flooding is possible, and the rivers will continue rising. The latest information on river flood warnings is available at WAAYTV.com at the top of the page. Driving will be dangerous. Remember to never try to drive through flood waters. That can be a deadly mistake. It puts your own life at risk, and it also risks the lives of your rescuers. Along with the river flooding, flash flooding is also possible. A Flash Flood Watch is in effect until 6 AM Saturday for all of the WAAY 31 coverage area in North Alabama and Southern Middle Tennessee.
While we will have areas of heavy rain around through the morning, breaks can become more common after the noon hour on Friday. Occasional rain can continue falling through Friday, Friday night and Saturday. Then an organized line of strong to severe thunderstorms will march from west to east across the Tennessee Valley Saturday evening. Once that line of storms exits east into Georgia around midnight Saturday night, we will set up for a string of dry days.
Damaging Severe Thunderstorms Possible Saturday Evening
Based on new data Thursday evening, conditions appear favorable for damaging winds over 70 mph, a couple of brief tornadoes, and destructive hail. Trees will not hold up well in the saturated and weakend ground, so they will topple with little effort from the wind. If that isn't enough, this line of strong to severe storms will bring a burst of heavy rain that will spike the flash flood risk.
Timing The Arrival
The threat begins between 6 PM and 8 AM over the Shoals, between 7 PM and 9 PM around Huntsville, Madison, Athens, and Decatur, and between 8 PM and 10 PM for Sand Mountain. The risk will be brief for any one location, but it will take almost six hours for the line of storms to track from the Mississippi state line to the Georgia state line. The storms will exit our DMA between 11 PM and midnight.
Additional Heavy Rainfall Could Mean More Flash Flooding
If that isn't enough, this line of strong to severe storms will bring a burst of heavy rain that will spike the flash flood risk. Rainfall totals through Friday and Saturday and into early Sunday morning could be an additional 1-3 inches on top of the more than 6 inches that have already fallen. Rain will end long before sunrise Sunday. Sunday will become partly to mostly sunny, and drying will begin. Monday and Tuesday will stay dry.