textproduct: Jackson

KEY MESSAGES

- Hot and humid weather persists at quite oppressive levels through the rest of the week, likely peaking on Thursday.

- Mostly dry weather is anticipated through Thursday, before chances for showers and storms return to end the week and over the weekend.

UPDATE

Issued at 626 PM EDT WED JUL 1 2026

The early evening update is out with no changes needed outside of updating near-term hourly T/Tds with the latest measured observations.

LONG TERM

(Friday through Wednesday) Issued at 359 PM EDT WED JUL 1 2026

At the onset of the long term period, eastern Kentucky will find itself on the western side of the aforementioned upper level high as the ridge finally begins to translate east and break down. High temperatures on Friday will remain well above average (generally in the upper 90s across the forecast area). However, given the eastward translation of the ridge, in addition to ample instability and an uncapped environment, convective coverage will likely be higher than in previous days, and any diurnally driven thunderstorm activity could reduce high temperatures. Further complicating matters, some models depict small scale impulses rotating along the periphery of the upper level ridge, which could provide an additional forcing mechanism for convective activity, especially for our western counties. In fact, a few models show a signal for MCS activity in the Ohio Valley late Friday, although confidence is low in this solution at this time. Given such a muggy and hot environment, instability will likely be anomalously high, with LREF mean SBCAPE exceeding 3000 J/kg in the western portion of the forecast area, although shear will be extremely low given exceedingly weak flow aloft. Accordingly, the Storm Prediction Center has introduced a Marginal (Level 1/5) Risk for severe thunderstorms across our entire forecast area, and machine learning guidance is in good agreement with this. Damaging winds associated with pulse convection would generally be the favored hazard in this environment; however, should an MCS solution come to fruition, the wind threat could be more widespread, and this potential will need to be watched as more CAMs become available. Regardless, convective activity is expected to decline overnight, with typical valley fog developing in mainstem river valleys.

The upper level ridge will continue to break down over our area this weekend, with marginally cooler high temperatures expected each day as upper level troughing gradually digs closer to our forecast area. To our north, a west to east oriented frontal boundary will sit over the Great Lakes region; however, with little to push this boundary south, it should remain relatively stationary through the weekend. In the absence of any larger scale forcing mechanisms, additional rounds of diurnally driven convective activity will be possible Saturday and Sunday afternoon, with increasing column moisture each day. The Weather Prediction Center has introduced a Marginal Risk (Level 1/4) for Excessive Rainfall on Saturday and Sunday to account for this moist environment; LREF mean PW values generally range from 1.5 to 1.7 in across the forecast area on Saturday, with marginally higher PW values on Sunday, especially in the northern portion of the forecast area. However, given the scattered nature of these storms, confidence remains low in any forecast rain totals or flash flood impacts at this time. On Independence Day specifically, weather will likely be hot (barring convective interference), with highs ranging from the low to mid 90s. Scattered storms capable of producing lightning and heavy downpours will be possible across the forecast area; thus, interests should remain weather aware during any outdoor celebrations Saturday afternoon/evening.

Moving into early next week, the aforementioned frontal boundary should eventually sag south as a slow-moving and weak cold front, leading to unsettled weather and mild relief from the heat. Shortwaves could provide reinforcement for additional convective activity, although model guidance diverges greatly with respect to the general pattern at this point.

AVIATION

(For the 00Z TAFS through 00Z Thursday evening) ISSUED AT 711 PM EDT WED JUL 1 2026

Mainly VFR conditions with light winds are expected through the period. Mainly valley fog is expected to impact portions of the region between 04z and 13z with MVFR or IFR reductions, or locally lower in some cases. The fog could again impact some or all of the TAF sites during the 08z to 13z timeframe. Opted to keep TEMPO groups with generally less reductions compared to what occurred this morning. Any fog should dissipate by 13z in all locations, with just some diurnally driven cumulus possible before the end of the period.

JKL WATCHES/WARNINGS/ADVISORIES

Extreme Heat Warning until 8 PM EDT Friday for KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120.