textproduct: Jackson

KEY MESSAGES

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

- Some storms on Saturday afternoon and evening could produce strong to locally damaging wind gusts.

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

UPDATE

Issued at 759 AM EDT FRI AUG 21 2026

Minor adjustments were made based on radar, satellite, and observations trends to convection near the KY border with TN and VA over the next couple of hours as well as the areal extent and intensity of fog. Overall, fog should lift and dissipate over the next 1 to 2 hours at the latest. Otherwise, convection may linger near the VA and TN borders over the next few hours though it could wane in coverage and intensity somewhat. Then, as the day progresses, coverage and areal extent should expand to the north and west, but generally remain south of the Mountain Parkway.

LONG TERM

(Saturday night through Thursday) Issued at 255 AM EDT FRI AUG 21 2026

The long term period will open with deep upper level troughing over the eastern CONUS and a high amplitude upper level ridge centered near the Four Corners region. At the surface, convection will be exiting far eastern Kentucky as the previous system departs. Meanwhile, a surface low will be located over the Great Lakes, with an additional cold front draped to the southwest. As this low lifts northeastward, its associated front will progress eastward into the forecast area on Sunday. Unlike the previous system, the frontal passage is expected to remain dry, owing to limited moisture ahead of the front. The main impact will be cooler and drier weather behind this boundary; dewpoints will fall into the 50s, and high temperatures will struggle to reach beyond the upper 70s to low 80s on Sunday afternoon. Overnight, clear skies and a weak pressure gradient will allow a modest ridge/valley temperature split to develop. MOS guidance could be slightly aggressive with this cooling for a few spots, but given the rather dry airmass (PW below the 20th percentile per LREF) should allow for rather ideal radiational cooling conditions, it seems plausible that low temperatures could fall into the mid 50s for valley locations, with typical fog formation.

Forecast uncertainty increases on Monday and Tuesday as eastern Kentucky finds itself on the western fringes of the progressing trough. Within increasingly northwesterly flow aloft, some model guidance suggests shortwave energy could spark additional rain chances as early as Monday afternoon, although ensembles still favor an anomalously dry environment through Tuesday overall. Given limited agreement in the evolution of these smaller scale impulses, PoPs remain low, with the exception of the southern portion of the forecast area where a slight chance of showers and storms was introduced. Although this highlights a marginally higher consensus regarding modest rain chances, forecast confidence is still low, and any coverage details will bear refining in the coming days. Barring convective interference, highs should still remain in the upper 70s to low 80s on Monday afternoon, with low temperatures in the mid to upper 50s across the forecast area overnight. On Tuesday, the eastward expansion of the upper level ridge will allow temperatures to climb a few degrees, with highs ranging from the low to mid 80s.

More robust rain chances will return by midweek as a closed upper level low progresses to the southeast from Manitoba into the Upper Midwest. In turn, deepening upper level troughing over the Midwest will lead to broad height falls across the Ohio Valley, with southwesterly to westerly surface winds allowing dewpoints to rise back into the upper 60s and low 70s. This, in combination with the potential for additional shortwave activity, will maintain PoPs in the neighborhood of 30-40% on both Wednesday and Thursday.

AVIATION

(For the 12Z TAFS through 12Z Saturday morning) ISSUED AT 810 AM EDT FRI AUG 21 2026

Fog lingers in valleys generally north of a KSME to KLOZ to KPBX line with reductions at mainly non TAF site locations to as low as VLIFR. KSJS had observed VLIFR/below airport initially. All locations experiencing fog should experience it lifting and dissipating through 13Z or 14Z. Otherwise, near the VA and TN borders, a passing disturbance is interacting with a frontal zone for a bit of convection. This may expand a bit in coverage north and west generally after 15Z or 16Z and linger as late as 23Z and affect locations near or just to the south of a line from KSME to KJKL to KSJS. Thereafter, valley fog should again develop and this may affect a few of the TAF sites during the 06Z to 12Z. As for winds, outside of any storms, winds will generally be light and variable.

JKL WATCHES/WARNINGS/ADVISORIES

None.