textproduct: Jackson

KEY MESSAGES

- Well-above normal temperatures persist into the weekend, with near-record heat possible over the Cumberland River Basin today. - The heat, humidity, and a nearby frontal boundary could foster isolated to scattered thunderstorms across the area at various times over the next several days.

- Rain chances increase early next week as the persistent upper level ridging breaks down.

UPDATE

Issued at 1036 AM EDT FRI SEP 18 2026

Updated PoPs and Sky grids with a general upwards revision through this evening, mainly in association with a broadly moist and unstable atmosphere and weak disturbance and surface cold front moving into the area from the northwest and north, respectively. Otherwise, high temperatures today were lowered slightly especially along the northeastern border with increased cloud cover and precipitation this morning. Otherwise, changes were minimal.

UPDATE Issued at 758 AM EDT FRI SEP 18 2026

Convection is dropping toward the I-64 corridor at update time. Maintenance of this convection is uncertain given weak instability and substantial CIN. If it diminishes as it settles southward as expected, additional development remains likely by the afternoon with diurnal destabilization. Forecast has been updated to include the latest PoP trends.

LONG TERM

(Saturday night through Thursday) Issued at 239 AM EDT FRI SEP 18 2026

Upper level ridging over the southeast CONUS will continue weaken as we move into the the long term period. Largely zonal flow aloft will be positioned just to our north at the start of the period. Multiple weak impulses moving through the flow will help to drive it very slowly southward as the upper high breaks down. By midweek, some semblance of an upper low is forecast to evolve near the Great Lakes, pushing faster flow aloft even further south for late week.

At the surface, this will eventually drive a significant cold front southward. This boundary should start the long term period to our north, near the Ohio River or further north, with its true position possibly somewhat muddled by prior convection. There is potential for some of this convection to feed off of our heat and humidity on this side of the front and make it south into our area in the Saturday night through Monday time frame, but confidence in details is very low due to mesoscale influences which would be in play. The greatest POP looks to be as the front pushes through. Models have not come into agreement yet, with cold fropa timing likely to be in the Tue-Wed time frame.

Noticeably cooler air should arrive behind the front as sprawling surface high pressure sets up in the vicinity of the Great Lakes and southeast Canada for late week. Our POP drops off with the change in air mass, but some light precip won't be completely ruled out, depending on the evolution of the persistent upper low/trough and any impulses rotating around it.

AVIATION

(For the 18Z TAFS through 18Z Saturday afternoon) ISSUED AT 139 PM EDT FRI SEP 18 2026

At 17z, remnant shower activity continues on a dissipating trend from this morning's shower and thunderstorms. However, scattered to numerous showers and thunderstorms will likely redevelop by 20z as strong diurnal heating and a humid atmosphere increases instability. While most of the daylight hours should remain VFR, showers and storms could lead to MVFR or lower reductions. Light and variable winds currently will increase to around 5 kts from the northwest to northeast as we near peak heating/mixing. Locally stronger and erratic winds are possible near convection.

Fairly widespread low stratus and/or fog is expected for much of eastern Kentucky tonight, especially in the wake of today's convection, with reductions to MVFR/IFR and perhaps lower are possible, especially between 06z and 14z, with improvements back to VFR conditions afterward through the end of the TAF period as low clouds burn off with daytime heating.

JKL WATCHES/WARNINGS/ADVISORIES

None.