First Alert out for strong storm threat Saturday

First Alert Forecast

We are giving the First Alert for Saturday for the possibility of: flash flooding, isolated damaging wind gusts and brief spin-up tornadoes. In that order.

Clouds returned today and the rain will return tomorrow. We expect periods of showers and thundershowers to develop throughout the day on Friday. Showers could continue Friday night into Saturday morning. Rainfall totals up to ½ inch are possible across the area Friday. A much stronger storm system will approach from the west by Saturday afternoon. There is the potential for strong to severe thunderstorms as we get later into the day on Saturday. The overall threat for severe storms in north Alabama and middle Tennessee will greatly depend on how unstable the atmosphere can get after the widespread showers on Friday. This rain-cooled area may not recover Saturday and that would be good news.

Currently, we are looking at what is called a high shear/low CAPE environment. This means there is a lot of spin in the air and we have strong dynamics in place for severe storms. However, if the air remains somewhat stable the storms would not be able to capitalize on these dynamics. Therefore, I’m continuing to lean towards the higher threat for severe storms and tornadoes to be to our south and west. There remains a lot of uncertainty to this forecast. If the boundary can recover and become unstable, we would have an increased threat for damaging winds and tornadoes by Saturday evening. Storm chances will decrease behind a front after midnight Saturday night. Flash flooding is possible if rain continues into Saturday morning. Two to three inches of rain on Saturday would create flash flooding and an increase in river flow. Just keep checking back for updates as we continue to fine tune the forecast.

Expect highs to return to the lower to middle 60s Sunday through Tuesday. We are watching Sunday with a 20 percent chance of rain due to the fact this cold front could hang up just to our south.

Another storm system will likely bring another round of thunderstorms and heavy rain Wednesday into Thursday of next week.

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