textproduct: Jackson

KEY MESSAGES

- A series of cold fronts will bring a possibility of showers and thunderstorms to the area at times through Saturday.

- Noticeably cooler and less humid air will arrive to start the new week, with mainly dry weather.

UPDATE

Issued at 1135 PM EDT THU AUG 20 2026

No significant changes were made to the forecast with mainly just the inclusion of the latest obs and trends for the T/Td/Sky grids along with a touch of the latest CAMs for possible convection sneaking out of Tennessee and affecting far southeast parts of the area into dawn. These minor adjustments have been sent to the NDFD and web servers along with a freshening of the HWO, SAFs, and zones.

UPDATE Issued at 740 PM EDT THU AUG 20 2026

23Z sfc analysis shows a weak cold front settling into eastern Kentucky this evening with just enough juice to cause a few showers to show up on the radar scope - threatening to kick off some occasional thunder. This boundary is apparently just north of the office and will keep a small threat for rain in the forecast along and south of it heading into the late evening. Otherwise, under partly cloudy skies, temperatures are running in the mid and upper 70s north and in the lower 80s for the south. Meanwhile, amid light winds, dewpoints are in the still sticky range of the mid to upper 60s north and the uncomfortable low to mid 70s south. Have updated the forecast mainly to add in the latest obs and trends for the T/Td/Sky grids as well as tweaking the PoPs through the night per the radar and most current solutions from the CAMs. These minor adjustments have been sent to the NDFD and web servers along with a freshening of the SAFs and zones.

LONG TERM

(Saturday through Thursday) Issued at 252 PM EDT THU AUG 20 2026

At the onset of the extended period, the upper air pattern continues to feature a prominent upper-level ridge centered over the Intermountain West and Four Corners Region. Further east, a large, neutrally oriented longwave trough is forecast to cover portions of the Central and Eastern US. An embedded shortwave within the longwave trough is modeled to dig out of northwestern Canada into the Great Lakes and Ohio Valley over the weekend.

A cold front will cross into eastern Kentucky, likely around or after 00Z Sunday (8 PM EDT Saturday). Isolated to scattered showers and storms are possible ahead of and along this cold front; PoPs reflect this through the afternoon into the early evening. Model soundings suggest MLCAPE ranging between 900-1200 J/kg at the time of the frontal passage, along with dew points in the upper 60s, and elevated DCAPE around 800-870 J/kg due to dry air in the mid-levels. With 0-6km effective bulk shear around 25 kts, storms could become better organized with potential for gusty and erratic winds. The SPC has placed portions of the area in a Marginal Risk (Level 1 of 5) which covers nearly all of eastern Kentucky north and east of a Somerset-to-London line, including the I-64, KY-15, and US-23 corridors to the WV/VA borders. Some models vary on the positioning of the trough, but general thinking is storms should taper off across counties bordering West Virginia in the late evening.

High pressure briefly builds across eastern Kentucky early next week, ushering in a cooler and drier airmass. Dew points lowering into the upper 50s and lower 60s will be a welcome relief from recent conditions. Dry weather remains Sunday through early Monday. Model discrepancies are resulting in low, isolated PoPs for Monday and Tuesday afternoon. This stems from the GFS being more progressive with a shortwave tracking out of the Central Plains into the Tennessee Valley, bringing low-end rain chances to portions of the forecast area. On the other hand, the ECMWF takes the shortwave out of the Central Plains and directs it deeper into the Southeast, leaving the area free and clear of active weather. The NBM has resolved this by placing 15 percent PoPs across the area to account for the possibility of the GFS solution.

Beyond Tuesday, multiple shortwaves embedded in the upper-level flow look to bring rounds of shower and storm chances to the area Wednesday and Thursday.

AVIATION

(For the 00Z TAFS through 00Z Friday evening) ISSUED AT 800 PM EDT THU AUG 20 2026

Dry weather and VFR conditions were still present at the TAF terminals for this 00Z issuance. There is a still a small potential for a thunderstorm or two in the late evening and overnight into early Friday, mainly near/south of the Cumberland Pkwy/Hal Rogers Pkwy/KY Hwy 80 corridor. This could bring isolated IFR or worse conditions. Fog is also expected in many locations (especially valleys) overnight and early Friday, with IFR or worse conditions possible even at the more elevated TAF sites. Improvement to VFR can be expected area-wide by late morning on Friday. Meanwhile, away from any storms, winds will be light and variable.

JKL WATCHES/WARNINGS/ADVISORIES

None.