Back-to-Back Storms Too Much for Parts of South

(May 3) -- The devastating flash flooding in Tennessee and Mississippi was the result of nearly four months worth of rain during a two-day span. And it came right after a similar storm system had pummeled parts of the South just a week earlier.

The slow-moving weekend storm system sent repeating waves of thunderstorms through western and central parts of Tennessee and northern Mississippi. Most of this region received 6 to 10 inches of rain, and weekend rainfall totals exceeded an incredible 15 inches in parts of Tennessee.

This is the amount of rain that typically falls from May 1 through about the middle of August -- all occurring in one weekend.

Rising rivers and streams demolished whatever was in their paths as they raced out of their banks and to record flood levels, and many highways turned into raging rivers. Hilly suburban locations resembled a series of lakes and islands, with lower elevations filled with water while homes or roadways in the higher spots peeked through the floodwaters.

Forty-nine reports of tornadoes were recorded from the Plains into the Tennessee Valley from Thursday through Saturday, including the deadly Arkansas tornado. The only tornado reports on Sunday occurred in southern Kentucky, just to the north of the Tennessee border, but there were several reports of tornadoes in western Tennessee and northern Mississippi on Saturday.

The bulk of the heavy rain had shifted to the east of the hardest-hit regions by Sunday evening. Some streams will fall quickly during the next couple of days, but serious flooding will continue. In fact, it will likely take until mid-week until some of the larger rivers crest given the tremendous amount of water that is moving into the river system.

The weekend storm system resembled the potent storm of the previous week, which spawned 141 tornado reports from the Plains to the Southeast. This included the deadly Mississippi tornado and numerous reports of flash flooding.

Both were strong late-season storm systems that pounded California with rain and mountain snow before losing some intensity when moving through the Rockies. The storms re-intensified once they arrived on the Plains, having warmth and moisture, brought in by a southerly flow from the Gulf of Mexico, to interact with. This warm, humid air had generally be lacking during the early part of tornado season, when far fewer tornadoes occurred than normal.

The weather pattern, fortunately, looks a little different for this week. Any storm systems during the first part of the week will track to the north of the region, resulting in generally dry weather. Showers and thunderstorms will likely return to the region by Friday, perhaps lasting into early Saturday. Any additional rain will be a concern, but it appears as if the storm system will not be as strong as the recent two, nor will it have as much moisture associated with it.

Let's hope so, since it will takes weeks -- or perhaps months -- for the region to make a recovery after back-to-back devastating storms.