textproduct: Jackson

KEY MESSAGES

- Mainly dry and cooler weather returns today through Wednesday, though locally dense river valley fog is expected late tonight.

- A cold front brings scattered to widespread thunderstorms Wednesday night and Thursday, with a few strong wind gusts and localized flooding possible.

- Noticeably cooler and less humid air arrives this weekend and continues into early next week.

LONG TERM

(Wednesday night through Monday) Issued at 435 AM EDT TUE AUG 18 2026

By Wednesday night, the cold frontal boundary will sag closer to the area and shortwaves riding through the broader upper level troughing will aid in forcing convection. This will lead to an increasing threat of showers and thunderstorms Wednesday night, with chances peaking in the 50 to 60 percent range near/north of I-64 and lesser chances (20 to 30 percent range) toward the Virginia border. The chance of showers and thunderstorms then increases further Thursday (50 to 70 percent range), as the frontal boundary sags deeper into Kentucky and a more pronounced shortwave arrives. There is a decent surge of moisture noted with the boundary, with PWAT values generally peaking in the 1.7 to 1.9 inch range, but the overall movement of this activity is expected to be rather progressive. Even so, locations that experience multiple rounds of convection could be at risk of minor flooding issues, and WPC does have all of eastern Kentucky in a Marginal Risk (1 out of 5) for Thursday into Thursday night. There is at least some question on the potential for a few stronger storms, with MUCAPE in the 1000-2000 J/kg range and effective shear in the 30-40 kt range. This is a reasonable enough parameter space to aid in organizing convection, with the main risk being strong wind gusts. This comes as DCAPE values increase toward 900 J/kg Thursday afternoon.

By the end of the week, the cold front is expected to slowly sink southward. There is some uncertainty as to how far, but enough to keep rain chances lower for Friday and Saturday, generally in the slight chance/chance range. Then by the late weekend into early next week there remains at least some model uncertainty with regard to the depth of the eastern CONUS trough as stronger shortwave drops out of the Northwest Canadian Arctic. Some guidance shows a closed upper low developing across the northern Ohio Valley/Eastern Great Lakes while 500 hPA ridging pumps back up over the Western CONUS. This could set the stage for a Canadian cold front to cross eastern Kentucky late Saturday or early Sunday with a subsequent early fall-like high pressure system to start the last full week of August.

AVIATION

(For the 06Z TAFS through 06Z Tuesday night) ISSUED AT 139 AM EDT TUE AUG 18 2026

A cold front is sagging southeast of the area early this morning. In its wake, a mixture of low stratus and fog is expected to develop in a weak northwest upslope flow regime, leading to the development of MVFR or worse conditions through daybreak. The low stratus and fog will gradually lift after sunrise and scatter out into a cumulus field during the afternoon. Winds will be light and variable through 12Z, then become northwest at less than 10 kts by late morning.

JKL WATCHES/WARNINGS/ADVISORIES

None.