textproduct: Jackson

KEY MESSAGES

- The potential for showers and thunderstorms will persist through the weekend.

- Some of the storms could arrive as organized clusters with a possibility for strong to damaging wind gusts. - Excessive rainfall may occur where storms are most persistent, or train, leading to flash flooding.

- Heat indices will flirt with Heat Advisory levels (105F +) again on Sunday afternoon.

LONG TERM

(Monday through Saturday) Issued at 510 PM EDT SAT AUG 15 2026

The long term period will open with upper level ridging over the southern CONUS and troughing over the Northern Plains into the Upper Great Lakes region, maintaining northwest flow aloft. Meanwhile, at the surface, an area of low pressure will be located in the vicinity of western Kentucky, with a frontal boundary sitting just west of the area. This boundary will push through the forecast area as a cold front on Monday, bringing renewed shower and storm chances. As in previous days, the environment will be very moist, with PW values generally in the range of 1.7-1.9 in. Thermodynamic profiles also look to be supportive of torrential downpours, with a deep warm cloud layer and LREF mean MUCAPE in the range of 2000-2500 J/kg across the forecast area. Given these indicators and the expectation that soils will be fairly saturated, isolated flash flooding will be possible. In fact, WPC has placed the entire forecast area in a Day 3 Marginal (Level 1/4) Risk for Excessive Rainfall to cover this flash flood threat. Rain chances will peak Monday afternoon into evening; then, following the frontal passage, drier air will advect in from the north. By Tuesday, dewpoints will be only in the mid to upper 60s, with perhaps a few areas in the 70s in the southwestern corner of the forecast area. Highs will also be marginally cooler, generally in the mid to upper 80s, and rain chances are looking to be low. Of note, a few recent model runs do depict subtle shortwave energy traversing the area, which could inspire a few showers or storms, although this scenario still appears unlikely at this time.

The next robust rain chances will arrive Wednesday evening into the overnight hours. Aloft, troughing will continue to dig into the Great Lakes region, and the ridge to the south will continue to flatten. Meanwhile, an additional cold front will push southeast, with rain chances ticking up again late Wednesday. Moisture will return quite quickly as winds become southwesterly ahead of the front, and PW values look to leap again too (with LREF mean PW in the 1.6-1.7 in range for much of the area, representing at least the 75th percentile compared to climatology). As in previous days, this environment could support at least an isolated flash flooding risk; WPC has again placed the majority of the forecast area in a Day 5 Marginal (Level 1/4) Risk for Excessive Rainfall (covering Wednesday morning through Thursday morning).

Behind the front, temperatures will be noticeably cooler. With eastern Kentucky sitting near the base of the upper level trough, flow aloft will either be zonal or northwesterly, with models still disagreeing about the exact orientation of the trough at this stage in the forecast. Regardless, this pattern will open eastern Kentucky up to additional shortwave impulses. Although exact timing is difficult to resolve at this timescale, broad rain chances have been maintained each day through the end of the period for now.

AVIATION

(For the 18Z TAFS through 18Z Sunday afternoon) ISSUED AT 300 PM EDT SAT AUG 15 2026

Mainly VFR was observed across eastern KY at issuance time, but cumulus had begun to develop across the north and east with some showers and thunderstorms across the region. KSME and KLOZ will be located further from the quasi stationary sfc boundary and closer to the upper ridge and will have the least chance for convection during the first 6 hours of the period as we move through peak afternoon heating. Meanwhile, isolated to scattered showers and thunderstorms are anticipated elsewhere with brief reductions to MVFR or even lower along with wind gusts up to 30KT. Some convection could affect areas from near KIOB to KJKL and points north and east including KSYM and KSJS during the second 6 hours of the period as a disturbance passes. However, following afternoon convection there is uncertainty the extent of any of this possible activity. Thus, PROB30 groups were restricted to the timeframe through 00Z and left out after. Some fog or low stratus could also become a concern, but confidence outside of the deeper valleys in the north and east was too low low to include at any of the TAF sites at this point. Winds will generally be 10KT or less, except locally stronger and erratic near thunderstorms.

JKL WATCHES/WARNINGS/ADVISORIES

Heat Advisory until 8 PM EDT this evening for KYZ083.