textproduct: Jackson

KEY MESSAGES

- A cold front sags into the Commonwealth today, and stalls out across southern Kentucky. This allows additional storms to potentially produce heavy rain in the Cumberland River Basin.

- A more significant cold front could produce multiple rounds of thunderstorms on Tuesday and Tuesday night. Those storms will be capable of producing damaging wind gusts and excessive rainfall.

LONG TERM

(Tuesday through Sunday) Issued at 340 PM EDT SUN JUL 19 2026

The extended forecast period will start out active as Mondays warm front lifts north through the area, bringing an increase in shower activity overnight Monday into Tuesday morning. Along with the potential for early morning shower and thunderstorm activity, an MCS is forecast to track southeastward toward the CWA from the southern Great Lakes. The 18Z CAMs suite is starting to resolve this feature at the far end of the forecast cycle. Model soundings ahead of the approaching MCS depict a highly potent thermodynamic environment capable of supporting strong to severe thunderstorms, with damaging wind gusts serving as the primary threat.

The 12Z NAM forecast sounding reveals MLLCAPE values exceeding 2500 J/kg, effective bulk shear around 50 knots, and ESRH values near 175 m2/s2. Additionally, 0 to 3 km shear vectors of approximately 30 knots oriented orthogonal to the forecast UDCZ indicate that the MCS will propagate into an environment highly favorable for maintaining convective organization, where damaging wind signatures and brief spin-up tornadoes are possible. However, uncertainty remains due to meager low and mid-level lapse rates, which may act as a limiting factor for deeper updraft acceleration. As well as, the potential for ongoing shower and thunderstorm activity that could overwork the atmosphere and atmospheric recovery doesnt occur. Nonetheless, the area is under a SPC Day 3 Enhanced Risk for much of the area and areas not in the Enhanced area are in the Slight Risk category.

In addition to the severe weather risk, an elevated hydrologic threat is forecast to develop. The southern flank of the MCS is expected to become the focus for training thunderstorms. Deep moisture will be in place with forecast precipitable water (PW) values exceeding 2.00 inches. This exceptional moisture profile will support highly efficient rainfall rates over already saturated soils, increasing the risk for flash flooding. Furthermore, ensemble probabilities indicate that integrated water vapor transport will approach the 99th percentile of climatology. In collaboration with the Weather Prediction Center, the Day 3 Slight Risk Excess Rainfall Outlook has been expanded to encompass the entirety of the JKL CWA.

As the forecast MCS and the actual cold frontal squall line exit the area through the day Wednesday, surface high pressure will gradually build into the region. This will usher in a period of dry weather and slightly below seasonal temperatures through late Friday afternoon. Extended guidance then suggests that the next low pressure system will bring a return of shower and thunderstorm chances beginning late Friday evening and persisting through the remainder of the weekend.

The extended period opens with a high-impact weather setup as a potent MCS and cold frontal squall line moves into an unstable, highly sheared environment on Tuesday. This system brings a distinct threat of damaging winds, brief tornadoes, and flash flooding. A cold front cleans out the area Tuesday night, introducing a cooler and drier high-pressure regime from Wednesday through Friday afternoon before another storm system brings renewed rain chances for the weekend.

AVIATION

(For the 18Z TAFS through 18Z Monday afternoon) ISSUED AT 134 PM EDT SUN JUL 19 2026

A combination of MVFR and VFR observations exist across all TAF sites with this issuance as a slow moving cold front is working through the area. Showers and storms have developed and presently staying clear of TAF sites; however, shower and storm potential will persist through the sunset before dissipating. Clearing skies will allow for fog development which could create MVFR to IFR fog through sunrise. VFR conditions will build back into the area for the rest of the TAF window.

JKL WATCHES/WARNINGS/ADVISORIES

None.