The Storm Prediction Center has our northwestern counties under their "Slight Risk" for severe weather though 7am tomorrow morning (graphic 1), and the rest of Middle Tennessee under the "Slight Risk" for much of the rest of the day (graphic 2).
They have us in a 30% chance for severe weather within 25 miles of a point (graphic 3). This could include damaging winds and isolated tornadoes.
My new "Estimated Time" map shows not only ETA, but how long storms will last. REMEMBER, this could change, so give or take a few hours.
Although some of the parameters don't look as ominous as they did with previous model runs earlier this week, just enough shear and instability should exist for severe weather to occur (for weather geeks 0-3km SRH 150-200 m2/s2).
However, there is one thing that I want to note:
These storms will be pushing into west Middle TN and even Nashville when there is very little heating, taking a way at least some of the instability. However, as they push VERY SLOWLY eastward during the day, the temperature should rise as well as our dew points, increasing the instability.
For weather geeks, the CAPE (convective available potential energy) goes from very little to up to 750 j/kg in the midday to mid afternoon hours when the storms should be just east of Nashville.
I'm not saying that from Nashville west will not see severe weather (wind shear is still high enough for severe). BUT the instability will likely get worse in the eastern half of Middle TN during the day, possibly creating worse severe weather chances there. That will bear watching into the mid afternoon hours.
Another note is that some models are moving the system even slower than we are forecasting. Should that occur, more instability even farther west.
Lisa will have more on News 2 this evening, and I will be joining Justin Bruce in the morning and during the day, so we've got you covered!