textproduct: Jackson

KEY MESSAGES

- Hot conditions will persist through Friday. The hottest conditions are expected on Thursday with widespread maximum heat indices in the low to middle 100s.

- Showers and thunderstorms are possible at times from Friday through early next week.

LONG TERM

(Friday through Wednesday) Issued at 346 PM EDT WED SEP 2 2026

At the start of the long term period, eastern Kentucky will still be feeling the influence of anomalously strong upper level ridging, although less strongly than in previous days. Meanwhile, troughing associated with a closed low over Quebec will sit due north of the forecast area, with another trough over the western CONUS. Throughout the day, this pattern will amplify significantly, with flow over the forecast area becoming northwesterly by the afternoon and evening hours as the eastern CONUS trough digs farther south and ridging retrogrades westward. The breakdown of this ridge over our area will allow for marginally cooler temperatures compared to previous days (with highs generally in the low 90s, barring any convective interference). This will also support a more active pattern overall. Rain chances return to the area as early as Friday afternoon/evening as a shortwave approaches ahead of a weak cold front. Isolated to scattered thunderstorms will be possible with this feature, particularly in the northern and eastern portions of the forecast area where height falls will be the most robust. Given the hot and moist weather, storms will have ample instability to work with, and strong to perhaps severe thunderstorms are not off the table. LREF mean surface CAPE values look to be around 2000 J/kg across the forecast area on Friday afternoon, with individual deterministic model soundings showing even stronger instability (in excess of 3000 J/kg). Shear looks to be fairly unimpressive, with bulk shear generally in the 20-25 kt range and hodographs generally unidirectional; however, with some models indicating the potential for convection moving through eastern Kentucky very early Friday morning, it is not inconceivable that any lingering boundaries could serve to enhance shear locally, although it remains much too early to pinpoint specifics. Given this environment, the Storm Prediction Center has placed eastern Kentucky in a Marginal (Level 1/5) Risk for Severe Weather, with damaging wind gusts as the primary hazard. Atmospheric moisture will also be rather high, with LREF mean PW values in the 1.5-1.7 in range (80th percentile or higher compared to climatology). As such, torrential downpours will also be possible within thunderstorms.

Overnight Friday into Saturday morning, the aforementioned cold front will sag south through eastern Kentucky, providing another focus for showers and storms. There is still significant model disagreement regarding the timing and extent of convective coverage associated with this frontal passage, resulting in NBM PoPs likely being a bit underdone compared to true rain chances, although uncertainty remains too high to refine these PoPs at this time. Adding to this uncertainty, some deterministic guidance depicts MCS activity diving southeast out of the Midwest during the day, following the periphery of the ridge. Thus, although rain appears likely at some point on Saturday, the details remain unclear at this time. For now, the NBM keeps PoPs generally low, maximized in the 20-30% range, to account for this. Meanwhile, northerly postfrontal winds will keep highs in the upper 80s on Saturday afternoon, with low 90s near the KY/TN line.

Rain chances look lower from Sunday onward as the upper level ridge begins to expand to the east. With surface high pressure building to the northeast of the forecast area, northeasterly winds will keep Sundays temperatures cooler than at the start of the period (but still quite warm). Dewpoints look to be modestly lower as well (in the 60s rather than the 70s), and this dry pattern will continue through the end of the period. Even so, Labor Day looks to be quite warm, with above average temperatures in the upper 80s expected across the area. Other than this the weather will be quite pleasant and sunny, with the exception of an isolated diurnally driven thunderstorm in far southeastern Kentucky.

AVIATION

(For the 18Z TAFS through 18Z Thursday afternoon) ISSUED AT 324 PM EDT WED SEP 2 2026

At TAF issuance, a shallow cumulus field had bubbled up across the area. VFR conditions will largely prevail during the the TAF period, except for fog redevelopment in valleys tonight, generally after 06z. Confidence in fog reaching any TAF site is too low to include at this time. The fog will lift on Thursday morning with the return of a cumulus field during the afternoon. Winds will remain light and variable.

JKL WATCHES/WARNINGS/ADVISORIES

Heat Advisory until 8 PM EDT Thursday for KYZ044-050>052-058>060- 068-069-079-080-083>085-104.

Heat Advisory from 11 AM to 8 PM EDT Thursday for KYZ086>088- 106>120.