textproduct: Jackson

KEY MESSAGES

- Mainly dry weather is expected through mid week, along with a warming trend. Peak afternoon heat indices are forecast to top 100 degrees in some locations Tuesday through Friday.

- Showers and thunderstorms are possible at times from Thursday into the weekend.

UPDATE

Issued at 820 PM EDT SUN AUG 30 2026

Minor adjustments were made to hourly grids mainly to account for some valley locations having already decoupled as we approached and have not passed sunset.

LONG TERM

(Tuesday through Sunday) Issued at 407 PM EDT SUN AUG 30 2026

The main story of the long term period will be heat. On Tuesday morning, there is high confidence that an anomalously strong upper level ridge will sit directly over Kentucky. LREF mean 500-mb heights reach 595 dam across the forecast area, representing the 99th percentile when compared to climatology, with minimal spread among ensemble solutions. Subsidence associated with this ridge should suppress convection, keeping weather dry and PoPs near zero through at least midweek. Meanwhile, at the surface, high pressure over the Southern Appalachians will keep winds out of the southwest across the forecast area, maintaining a moist air mass across eastern Kentucky. There is still some uncertainty regarding how high dewpoints will climb, owing to model disagreement regarding the exact positioning of the surface high (and associated wind pattern); however, ensemble guidance indicates dewpoints in the mid to upper 60s are likely, with raw NBM output even suggesting widespread dewpoints in the 70s (with the highest dewpoints in our southwestern counties). Given that both ensemble and deterministic guidance favor a drier solution, these NBM dewpoints are likely overdone, and forecast dewpoints were nudged down a few degrees to better match model consensus at this time. Should this hold, we will narrowly avoid hitting heat advisory criteria, though apparent temperatures could reach the triple digits. Regardless, expect hot and humid weather on Tuesday and Wednesday. High temperatures will generally range from the mid to upper 90s, with the hottest temperatures closer to the I-64 corridor. Overnight, limited relief is expected; lows on Tuesday and Wednesday nights will range from the upper 60s in sheltered valley locations to the low 70s on ridges, with typical valley fog formation likely.

A pattern change is expected on Thursday as upper level troughing over the Northeast digs southward, flattening and weakening the ridge over Kentucky. There is still some disagreement over how quickly this ridging will break down over us; however, high temperatures should cool from Thursday onward, and rain chances look to increase through the end of the period. With a trend toward northwesterly flow, pattern recognition suggests that this setup could open the door for multiple shortwave impulses to ride the periphery of the ridge. In fact, deterministic guidance shows a signal for MCS type activity to develop in the Midwest and progress southeastward with time, potentially into our area. That being said, the track of any convective complexes would depend on the position and strength of upper level ridging. Unfortunately, models disagree significantly on these details on Thursday and Friday; the ECMWF favors a more quasi-zonal pattern aloft during this time, while the GFS keeps flow more northwesterly, with a much more amplified ridge to the west over the Mississippi Valley. In both scenarios, some scattered showers and storms would be possible on Friday, but confidence in any further forecast details remains very low at this time.

By the weekend, models come into better agreement regarding a more robust northwest flow pattern aloft as ridging continues to amplify over the Plains. Meanwhile, at the surface, a weak cold front will sag south into the forecast area, providing additional forcing for more focused shower and storm chances, although details again remain quite uncertain at this stage in the forecast. Thankfully, temperatures will fall closer to normal around this time, bringing an end to any heat concerns.

AVIATION

(For the 00Z TAFS through 00Z Monday evening) ISSUED AT 820 PM EDT SUN AUG 30 2026

At issuance time a few patches of cumulus lingered, but this has continued to diminish. Otherwise, high pressure in place across the region will result in valley fog during roughly the 04Z to 13Z timeframe. This is not expected to affect the TAF sites and VFR should return to all locations by 14Z. Thereafter, diurnally driven cumulus in the 3 to 5kft agl range is expected to develop by the 16Z to 18Z timeframe though these should remain in the VFR range and a few spotty sprinkles or light showers cannot be completely ruled out from these. Winds will be light through the period.

JKL WATCHES/WARNINGS/ADVISORIES

None.