textproduct: Jackson

KEY MESSAGES

- Very warm and mainly dry weather will persist through Tuesday afternoon.

- Showers and thunderstorms enter the forecast late Tuesday into Tuesday night, then persist through next weekend.

- The switch to a wetter pattern yields temperatures closer to normal readings and produces a highly-beneficial, widespread wetting rainfall.

UPDATE

Issued at 920 PM EDT MON MAY 18 2026

Added a slight chance of a shower to far eastern parts of the area as a few have snuck across the border from Virginia. These will be fleeting and probably be gone well before midnight. Cannot rule out a stray bolt of lightning from these for the next hour or so. These minor adjustments have been sent to the NDFD and web servers along with a freshening of the zones and SAFs.

UPDATE Issued at 725 PM EDT MON MAY 18 2026

23Z sfc analysis shows high pressure to our southeast still in control of the weather over eastern Kentucky while a cold front is noted well off to the northwest. Strong storms are located closer to that boundary but will not make much progress toward the area through the night. However, they are pushing some high clouds and those may slow the temperature drop off this evening. Currently, temperatures are running in the very warm low to mid 80s. Meanwhile, amid southwest winds of 5 to 10 mph with some higher gusts, dewpoints are generally in the upper 50s to lower 60s. Have updated the forecast mainly to add in the latest obs and trends for the T/Td/Sky grids. These minor adjustments have been sent to the NDFD and web servers along with a freshening of the zones.

LONG TERM

(Wednesday through Monday) Issued at 343 PM EDT MON MAY 18 2026

If the long term period could be summarized with just one word, it would be wet. The period will open with broad ridging over the southeastern US and troughing over the Hudson Bay. This will leave Kentucky in a regime of generally southwesterly flow aloft at the onset of the long term period. At the surface, a cold front will extend through the CONUS from a surface low centered over Quebec and push into eastern Kentucky on Wednesday, although the exact timing of the frontal passage remains dependent the upstream evolution of this system. The environment ahead of the front will be moist (owing to prefrontal southwesterly winds), but instability will be dependent on whether the timing of the frontal passage can align with maximal daytime heating. Accordingly, LREF guidance still shows a wide range of MUCAPE values, but the most likely outcome at this time is that instability should be sufficient for a few thunderstorms. Given that wind shear is expected to be meager, widespread organized severe weather appears unlikely. A few machine learning sources have introduced very low-end probabilities for gusty winds Wednesday afternoon, but this threat remaining highly conditional on favorable frontal timing, and thus confidence remains very low in this outcome.

Regardless of storm strength, this system will bring much-needed rain to eastern Kentucky, which currently remains in drought (ranging from D1 conditions in our eastern forecast area to D2 and a pocket of D3 conditions in the western portion of forecast area). With broad ridging over the southeastern CONUS, the aforementioned cold front will struggle to push through into the Atlantic coast states and likely stall over the periphery of the ridge going into Thursday (TN area) before lifting into Kentucky again as a warm front on Friday. This pattern will bring multiple rounds of rain to the forecast area. As such, WPC has introduced multiple Marginal (Level 1 of 4) Excessive Rainfall Outlooks for the forecast area; one for our entire area on Wednesday, another for the Lake Cumberland area on Thursday, and a third for our entire forecast area again on Friday. QPF does not look overly impressive on any given day; LREF guidance shows that the chance of exceeding 0.5 of rain on any given day is low to moderate (maxing out at around 50% on Wednesday). However, this does not account for enhanced rain rates in any thunderstorms that do develop. If storms track over the same area for multiple days in a row, isolated instances of nuisance flooding cannot be ruled out. This is especially true closer to the KY/TN border, which will feel the greatest impacts of the stalling front. However, these details will need to be refined in the short term when convective rain rates can be better accounted for.

Thursday looks to be the coolest day of the period. Following the frontal passage, CAA via postfrontal winds will keep maxTs generally below normal, with a defined thermal gradient over our forecast area as the front stalls. Currently, the NBM is outputting highs in the 80s for the southern portion of our forecast area; however, this appears to be an outlier compared to other guidance, so maxTs were bumped down a few degrees on Thursday afternoon to better account for the frontal passage. After the front lifts northward again, flow will become more southerly, and temperatures will be warmer than on Thursday. The NBMs highs in the upper 70s and low 80s may be slightly overdone given that rain is likely going into Friday afternoon (80-90% chance), but highs do represent an expected warming trend as the warm front lifts northward. Unfortunately (for outdoor activities) or fortunately (for drought relief), this weekend also looks to be quite wet even as the original front exits our area. A slow- moving upper level trough over the central CONUS, in addition to potential embedded impulses, will allow for rain chances every day through the weekend and into the end of the period.

AVIATION

(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 745 PM EDT MON MAY 18 2026

VFR conditions under times of high clouds will prevail through the period. The one caveat will be some valley fog between 04Z and 13Z with local MVFR and IFR reductions that are not expected to affect any of the TAF sites. Otherwise, south to southwest winds will average 6 to 12 kts with gusts to near 20 kts initially but diminishing through the evening. Light and variable winds will be the rule overnight, before becoming south to southwest at 5 to 12 kts again with some gusts up to 20 kts for Tuesday afternoon. By the end of the period, look for some cumulus to again develop between 4 and 6kft agl.

JKL WATCHES/WARNINGS/ADVISORIES

None.