textproduct: Jackson

KEY MESSAGES

- The potential for showers and thunderstorms will persist this weekend across Eastern Kentucky.

- 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, leading to flash flooding.

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

UPDATE

Issued at 1220 PM EDT SAT AUG 15 2026

As of noon, temperatures have warmed to the 80s to around 90 with dewpoints mainly in the mid and upper 70s. Some agitated cumulus has developed over the past half an hour or so with a few stray showers southwest of JKL and also to the northeast of JKL and south near Hazard and the Harlan County vicinity. Some of these have managed to produce a bit of lightning activity. The more organized convection in IN and OH is moving more to the east and southeast at this time and appears destined to pass north and northeast of eastern KY this afternoon. However, with the warm and moist airmass in place and the presence of the agitated cumulus, isolated to scattered showers and storms are anticipated mainly in the north and east through early this afternoon. In addition, an outflow boundary/trough was moving across southeast IN and portions of Central to western KY this should reach eastern KY in a few hours and could be the focus for some convection that moves from central and into eastern KY similar to the 15Z HRRR. PW area wide is in the 1.75 to 2 inch range with the nearly stationary sfc boundary residing across the region that is nearly parallel to the upper flow. MLCAPE during the afternoon near 20Z is progged to generally reach the 2000 to 3000 J/kg range with MUCAPE more substantial than that. Effective shear remains a limiting factor generally 20KT or less, near the 20 to 25KT range in the north or in the SPC Day 1 Slight Risk area. Low level lapse in the 7 to 7.5C/km range and roughly 5.5 to 6C/km mid level lapse rates.

Clusters or more organized cells in the south could pose a marginal wind threats, with shear supporting slightly better chances later this afternoon to early this evening in the north. Any training would become a concern for high water or flash flooding as well.

Outside of convection, heat indices are warm generally peaking between 95 and 105, though some spotty lower elevation valley locations may reach 105 or higher briefly. The Lake Cumberland region especially Wayne County area should have the greatest coverage of this.

LONG TERM

(Sunday night through Friday) Issued at 751 AM EDT SAT AUG 15 2026

A ripple moving through the mid-upper level flow to our north will support a weak cold front which is expected to approach us Sunday night and move through on Monday or Monday evening. Deeper moisture should return ahead of the front, with our PWs rising to around 2" again. With this, the potential for thunderstorms returns. Drier air arriving behind the front will probably keep us mostly dry on Tuesday. However, there is a shortwave trough showing up in some of the latest guidance and results in a bit of spotty precip. The NBM forecast is dry on Tuesday. However, if the shortwave and its precip persist in later model runs, a low POP could end up in later forecasts.

The next significant shot at precip arrives in the neighborhood of Wednesday night and Thursday as an upper level impulse carves out an eastern CONUS trough. This sends another cold front southeast, with atmospheric moisture again increasing ahead of the front. Behind the front, there could be some noticeable relief from the mugginess at the end of the week.

AVIATION

(For the 12Z TAFS through 12Z Sunday morning) ISSUED AT 751 AM EDT SAT AUG 15 2026

A mixture of VFR to VLIFR conditions were noted across eastern Kentucky terminals at the 12Z TAF issuance with valley fog to blame for the localized sub-VFR reductions. The valley fog will lift/burn off quickly after 12Z. VFR conditions can then be expected for much of the daylight hours; however, diurnal destabilization and a lingering surface frontal boundary will lead to a renewed threat for scattered showers and thunderstorms during the afternoon and evening. In fact, an isolated shower or storm cannot even be entirely ruled out during the mid-to-late morning. 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.