Waffling Again
Tuesday, August 11, 2026 · 10:45 AM
Lyrics
Dangerous heat expected through the weekend with triple digit heat indices west of the Cumberland Plateau. Low to medium thunderstorm chances primarily east of Interstate sixty-five each afternoon and evening through Thursday. Stronger storms will be capable of damaging winds and heavy rain. Mid-nineties! Dewpoints in the seventies! Low triple digits! Northwest flow! Convection allowing models! Waffling! Mesoscale convective system! East of Interstate sixty-five! Downdraft convective available potential energy! Damaging winds! Heavy rain! Marginal risk! Conditional threat! High pressure building! Excessive moisture! Unstable air mass! No relief! Triple digits! Waffling models! Waffling! Waffling! Burn!
The forecast discussion
NEW SHORT TERM, LONG TERM
KEY MESSAGES
Updated at 1034 AM CDT Tue Aug 11 2026
- Dangerous heat expected through the weekend with triple digit heat indices west of the Cumberland Plateau.
- Low to medium thunderstorm chances primarily east of I-65 each afternoon and evening through Thursday.
Stronger storms will be capable of damaging winds and heavy rain.
SHORT TERM
(Rest of today through Wednesday) Issued at 1034 AM CDT Tue Aug 11 2026
High pressure will be building over the southeast US through the remainder of the week, allowing for temperatures to soar.
Highs this afternoon and again Wednesday will reach into the mid-90s for areas west of the Cumberland Plateau.
With dewpoints in the 70s, it'll feel humid which means that heat index values will get into the low triple digits both afternoons.
This high pressure won't completely suppress thunderstorms as it remains too far south through Wednesday, leaving us in northwest flow.
Northwest flow typically means that the door is open for MCSs to track south/southeast into Middle TN. Models do suggest this with CAMs showing the potential for an MCS this afternoon and evening and another Wednesday afternoon and evening.
CAMs do struggle tremendously in this type of pattern with runs this morning waffling on if we'll see any storms today.
If the do happen, plenty of instability, DCAPE, and moisture will be available to them, giving any storms the opportunity to produce damaging winds and heavy rain.
Primary threat will be for areas east of I-65. Marginal risks are in place for both today and tomorrow to highlight this conditional threat.
LONG TERM
(Wednesday Night through next Tuesday) Issued at 1034 AM CDT Tue Aug 11 2026
During the latter half of the week, high pressure will continue to build north, and temperatures will only get hotter.
High temperatures will get into the upper-90s for many locations west of the Plateau Thursday into Saturday, and then we may even be talking about triple digit heat by Sunday.
At Nashville, the NBM gives an 80% chance of hitting 100 degrees Sunday.
Even if we don't hit triple digits, this heat wave will still be dangerous.
This prolonged stretch of hot temperatures will make for major to extreme heat risk for all.
So be sure to take care of yourself and check on others who may be more sensitive to heat.
Unfortunately, overnight won't offer much relief with lows in the mid to upper-70s with high humidity.
As far as rain goes, the more this high pressure builds overhead, the more rain chances go down.
There are low rain chances Thursday & Friday, but the weekend looks to be dry which coincides with the hottest temperatures.
The heat should break early next week as the high moves west and a boundary comes down from the north.