textproduct: Jackson

KEY MESSAGES

- Multiple rounds of showers and thunderstorms are expected today through tonight. Slow storm motions and high humidity will support torrential downpours and an isolated flash flood risk, especially across the Cumberland River Basin.

- Rain chances decrease on Wednesday, leading into a hot and humid Thursday. Highs will approach record territory in the up- per 80s to near 90 degrees, with heat index values peaking in the mid to upper 90s.

- A cold front brings widespread showers and thunderstorms back to the region Friday afternoon and evening, accompanied by another risk for locally heavy rainfall.

- Drier, more comfortable weather returns for most of the area on Saturday behind the departing cold front.

UPDATE

Issued at 1002 AM EDT TUE JUN 9 2026

Blended morning obs into the forecast, without any overall substantive changes.

UPDATE Issued at 800 AM EDT TUE JUN 9 2026

The MCV continues to maintain as is approaches from Central Kentucky just after daybreak. Rain is already moving into the Lake Cumberland area at update time and it is expected that much of the area will experience a period moderate to heavy rain with embedded thunder. CAMs, in the particular the HRRR, are struggling to resolve this system. However, as long as the system is able to maintain its moisture and instability feed, anticipate that this system should reach the US-23 corridor by around 15Z, but the overall system evolution is quite uncertain.

LONG TERM

(After midnight Wednesday night through Monday) Issued at 615 AM EDT TUE JUN 9 2026

The period opens with an upper level ridge over the eastern and south central CONUS, with a deep trough centered over the High Plains. At the surface, an area of low pressure will sit near the border of Manitoba and Ontario, with a warm front draped to the southeast through Ontario and into the Great Lakes region. Additionally, a cold front will extend southward through the upper Midwest and into the Plains. With a surface high located over the Southern Appalachians, moisture advection via southwesterly winds will continue to maintain a muggy air mass in eastern Kentucky. Dewpoints will range from the upper 60s to the low 70s, but with ridging aloft, a relative lull in convective activity appears favored compared to earlier in the week (although there is still some model disagreement regarding the robustness of this ridging). Assuming rain chances remain low, Thursday looks to be the hottest day of the forecast period, with highs extending into the upper 80s or perhaps low 90s per the NBM; this is supported by LREF mean 850 mb temperatures of around 20C, in addition to current MOS guidance, so Jacksons record high of 90 degrees could be in jeopardy, contingent upon a break in convection. Also, given the moist air mass in place, apparent temperatures could soar into the mid to upper 90s in some locations. Overnight, temperatures should range from the mid 60s to the low 70s, with a modest ridge-valley temperature split developing under mostly clear skies and a marginally weak pressure gradient over the forecast area.

By Friday, the eastward progression of the upper level trough will push the Canadian surface low into Ontario, with the associated cold front entering Kentucky by the afternoon. Accordingly, showers and storms will be likely, with rain chances maximized in the afternoon and evening hours. Given the pre- existing moist airmass, mean LREF PW values will be in the neighborhood of 1.6-1.8 inches ahead of the front; therefore, there will be yet another chance for locally heavy rain and isolated flash flooding. This moist air mass will also allow for moderate instability to build with daytime heating; however, given Kentucky will be located south of enhanced flow associated with the upper level trough, shear will be modest at best, and there will be diminishing upper level support for the front as it pushes through our area. Additionally, there is still some disagreement on the time of the frontal passage, with many models suggesting the front could pass through our area overnight Friday into early Saturday morning. This more unfavorable timing, in addition to a lack of shear, indicates that widespread severe weather is not currently expected, although frontal timing will bear some monitoring in subsequent forecasts. Behind the front, drier air will filter in as winds become more northerly with time, and dewpoints will drop back into the low to mid 60s by Saturday morning, allowing for cooler lows than previous nights.

Saturday will bring comparatively pleasant weather as postfrontal winds keep highs confined to the mid 80s, a few degrees cooler than in previous days. With the cold front having pushed south out of our area, mostly sunny and dry conditions will be favored. However, the front will eventually stall as it outruns upper level support, and uncertainty still remains regarding where this will happen, with a relatively thin margin separating eastern Kentucky from the most likely positioning (NC/TN) of this front going into Saturday evening. Therefore, the NBM has maintained some isolated PoPs in our southeast to account for this uncertainty. Looking ahead, eastern Kentucky will be under the influence of upper level troughing for the remainder of the forecast period. Rain chances look to return on Monday as another front approaches the area, although uncertainty still remains high with this next system.

AVIATION

(For the 18Z TAFS through 18Z Wednesday afternoon) ISSUED AT 220 PM EDT TUE JUN 9 2026

Conditions varied widely at the start of the period, with reports of LIFR to VFR in the forecast area. The most widespread poor conditions were generally north of the Mountain Parkway, where rain has been ongoing. However, there are also isolated showers and thunderstorms further south.

Widely varying conditions are forecast to persist through the period, with showers and thunderstorms at times. Aside from the precip slowly winding down in the north currently, the greatest potential for showers and thunderstorms is overnight into Wednesday. However, confidence in the timing/location is rather low, and this is reflected by liberal use of PROB30 and TEMPO groups in the TAFs.

JKL WATCHES/WARNINGS/ADVISORIES

None.