A flash flood watch is in effect for the entire Tennessee Valley through Tuesday evening. Localized flooding is likely to occur in the next 24 to 48 hours.
Periods of moderate to heavy rainfall will continue through the rest of the evening into the overnight hours. An additional 2 to 3 inches of rain will be possible.
Due to the threat of heavy rain overnight, we have declared Tuesday a First Alert Weather Day for potential flooding of roadways, creeks, streams, area rivers and low-lying areas. Please use extreme caution during the morning commute on Tuesday. If you encounter a flooded roadway, please turn around and find an alternative route.
Rain showers will continue off and on throughout Tuesday with cloudy skies and highs in the 50s. More dry hours will be expected in the afternoon. The First Alert is also out for the potential of strong to severe thunderstorms Wednesday evening. Right now, it looks like a line of thunderstorms will move through Wednesday night that will bring additional heavy rainfall, frequent lightning, damaging winds gusts and even isolated tornadoes.
This threat will end early Thursday morning and rain showers should wind down by Thursday afternoon. Colder air will move in by Friday with mostly sunny skies and highs in the middle 40s.
The entire Tennessee Valley has been placed in a Flash Flood Watch through Tuesday afternoon. Showers will remain persistent throughout the day today and overnight and by the time we get a brief break later in the morning tomorrow, many of us will have seen 2 to 5 inches of rain. Localized heavier totals of 6 inches or more are possible for some communities as well.
Unfortunately, tonight & tomorrow are not the only days this week that we will see rainfall. More heavy rain is expected Wednesday and Thursday as a second low pressure system will come through the Tennessee Valley later in the day Wednesday. This could bring an additional 2 to 4 inches of rain for much of the area, which will just increase the flooding threat. All in all, parts of the Valley could see anywhere from 5 to 8 inches of rain by the end of the week, with localized amounts possibly as high as 7 to 10 inches.
River flooding will also be an issue as we move into later parts of the week. The Tennessee River is expected to reach moderate flood stage, if not major flood stage, by Thursday in both the Florence and Whitesburg (Ditto Landing) locations. Right now, the river levels in Florence are expected to crest near 27’, which is shy of the 28.99’ level that it crested at last February. At the Ditto Landing location water levels are expected to crest near 25’, which would be two feet higher than the 22.90’ last February, which would lead to greater flooding for areas along the riverbank. Runoff from the rainfall will also lead to some minor to moderate flooding for area streams and creeks as well as other local tributaries.
On top of the flooding threat this week we also have a threat of strong to severe thunderstorms late Wednesday afternoon and evening. The Storm Prediction Center already has the entire Tennessee Valley in a Slight Risk for severe storms in their Day Three Outlook. However, it is still early in the process and confidence is low right now on timing and severity. IF storms do pan out, it looks like it will be a late afternoon and evening event with storms firing up during or after the evening commute. Right now, the main threats look to be damaging wind gusts and a few tornadoes. However, I think flooding is the bigger threat. Keep checking back for more updates online and on our 48 First Alert Weather App as we get closer.