30% wind threat (red)
15% hail threat (yellow)
2% tornado threat (green)As low pressure moves up the Ohio River Valley this afternoon, the News 2 viewing area will find itself in the storm system's "warm sector." That's the area between the warm front and cold front, where southwest winds carry in warm and muggy air that can be favorable for thunderstorm development.
Scattered thunderstorms are going to be possible between noon and approximately midnight, when the cold front sweeps across the Mid-South. The most likely threat will be damaging winds. Hail will also be possible, and at this point the tornado threat appears relatively small. The images I've posted show the Storm Prediction Center's percent forecast of those types of severe weather (the likelihood of happening within 25 miles of a specific point, like your house).
The computer models depict impressive instability levels this afternoon. We measure instability with a variable called CAPE, which stands for convective available potential energy. CAPE is a good proxy for how strong the updraft in a thunderstorm can become; the higher the values, the more explosive the storm. CAPE values should exceed 1000 Joules/kg this afternoon, which is usually the minimum cut-off for strong storms in Tennessee. The NAM model predicts CAPE values near 2500 J/kg this afternoon and the GFS has them near 2000 J/kg.
