textproduct: Jackson

KEY MESSAGES

- Well-above normal temperatures persist this weekend with near record values both days over the Cumberland River Basin. - 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 1119 AM EDT SAT SEP 19 2026

Isolated showers and thunderstorms have developed amidst weak elevated instability as a warm frontal boundary slowly drifts northeast toward the Eastern Kentucky Coalfields. Low end PoPs have been added into the forecast to account for this. More widespread PoPs are expected to hold off until late afternoon/ evening when convection, potentially associated with an upstream outflow northwest of Indianapolis, approaches/develops.

LONG TERM

(Sunday night through Friday) Issued at 342 AM EDT SAT SEP 19 2026

A rather chaotic upper level setup is anticipated across the CONUS to start the long term period. The main belt of prevailing westerlies aloft will be well to our north, largely in Canada. South of that, a number of features semi-disconnected from the main flow will be over the CONUS, but with largely zonal flow over the Ohio Valley and little flow to the south. A surface frontal boundary should be stalled over or near KY along the southern edge of the flow aloft. This boundary could serve as a broad focus for convective development Sunday night into Monday.

The most significant feature aloft for our local area at the start of the period will be a trough (and possibly weak low) over the northern plains. This feature traces back to a current position over ID. As it drifts east, models are in relatively good agreement through Wednesday for it to form a larger closed low near the Great Lakes. The resulting trough over the eastern CONUS will support a transition to cooler weather, but the details of potential fropa for the local area are a little messy, as the cooler air is expected to make better progress down the eastern side of the Appalachians. This potentially pinches the warmer air mass along the western side here. We should see an increased POP with the transition in air masses around mid week, but the details are murky as to how/when a full transition eventually takes place. Model solutions also begin to show more variation with the evolution of the upper low at the end of the week, particularly in the way it shifts east and with ridging trying to build east toward the Great Lakes. This lowers confidence in the forecast at the end of the period.

AVIATION

(For the 18Z TAFS through 18Z Sunday afternoon) ISSUED AT 231 PM EDT SAT SEP 19 2026

A band of showers/thunderstorms extended from the vicinity of KJKL southward into VA and TN at the start of the period. This was due to elevated (non surface based) instability based around 6K ft AGL. It should be passed KJKL very shortly and it's unclear if this elevated activity will affect KSJS as it creeps eastward. As surface temperatures climb, surface based convection may result in a few additional surface based showers/thunderstorms late this afternoon and evening, but the the probability looks too low at any TAF site to explicitly address it. If it looks apparent that the threat is increasing, AMDs will be necessary.

Away from precip, VFR conditions are expected into tonight. Valley fog is likely to develop overnight and last into Sunday morning, especially in extreme eastern and southeastern KY. It could affect some TAF sites at times. Once fog dissipates on Sunday morning, VFR follows area wide again through the end of the period

JKL WATCHES/WARNINGS/ADVISORIES

None.