455 FXUS63 KJKL 031832 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 232 PM EDT Fri Oct 3 2025 .KEY MESSAGES... - Dry and generally above normal temperatures persist into early next week. - Into the weekend, valley fog is likely to develop each night. - Chances for rain will return for Tuesday and Wednesday. && .SHORT TERM...(This evening through Saturday night) Issued at 232 PM EDT FRI OCT 3 2025 This afternoon through Tonight: Guidance remains consistent for the short-term. High pressure will dominate from the north and east, extending into the Ohio and Tennessee Valleys. Aloft, a 500mb ridge will shift eastward but maintain control. Expect isolated high thin cirrus and perhaps a few cumulus clouds this afternoon. These will clear tonight as daytime heating diminishes, leading to ridge/valley temperature splits, with upper 40s to lower 50s in valleys and mid to upper 50s on ridges. Valley fog is also possible overnight. The lower valley temperatures are being captured well by the COOP MOS guidance and closer to the 5th percentile of the NBM. Saturday: Surface high pressure and upper-level ridging will continue to influence the weather across the Ohio valley. Once again the short-term guidance and forecast soundings indicate the potential for a few cirrus or shallow cumulus clouds at most given the dry air in place. It will be another warm day with mostly sunny skies and light surface winds. Highs are expected to reach the lower 80s for most locations, with some maybe slightly warmer (a couple of degrees) than today base on the ensembles and deterministic guidance. Saturday Night: Afternoon clouds will dissipate, resulting in mostly clear skies, with the exception of a few high clouds in the far southeastern portions of the area. Overnight lows will exhibit a persistent pattern of ridge/valley splits, with temperatures ranging from the upper 40s to lower 50s in valleys and mid to upper 50s on ridges. One again valley fog is also possible. Once again, the lower valley temperatures are being captured well by the COOP MOS guidance and closer to the 5th percentile of the NBM. .LONG TERM...(Saturday night through Thursday) Issued at 510 AM EDT FRI OCT 3 2025 The main changes to the extended forecast this morning were to enhance the terrain based differences for more in the way of ridge to valley temperatures splits each night through next weekend. Did also tweak afternoon dewpoints a tad lower due to dry air mix-down anticipated. The PoPs are still looking quite limited up until Monday afternoon. The previous long term discussion follows: Very little change is anticipated in the overall synoptic pattern going into the extended forecast period, as the upper- level ridging persists with the ridge axis positioned directly over the CWA. Simultaneously, a closed upper-level high remains situated over the Gulf Coast. However, to the west, an advancing upper- level longwave trough and associated jet streak are poised to move off the Rockies and into the Central Plains. At the surface, a low-pressure wave will similarly track eastward off the Rockies and slowly eject northeastward into the Upper Midwest through the rest of the weekend. Models suggest this system will track mainly through southern Canada, but will leave a trailing area of surface baroclinicity. This baroclinic zone will be a crucial focus for the development of the next system, as another upstream shortwave is forecast to develop and move over this area of baroclinicity, leading to the cyclogenesis of a new surface low by the start of Tuesday. With this cyclogenesis occurring and the associated upper-level trough digging southeastward, the new surface low and its attendant frontal boundaries are forecast to approach the area for Tuesday night into Wednesday. Showers and possibly a few thunderstorms will be possible with FROPA. However, the frontal timing is currently forecast to be overnight Tuesday into Wednesday, which will limit available daytime instability. Furthermore, long-term guidance indicates the potential for diurnally driven CI earlier on Tuesday afternoon as southeasterly to easterly flow, around a surface high pressure center, advects moisture rich air into, which could consume all available atmospheric instability, thus largely negating the potential for organized overnight convection with the front. There remains uncertainty regarding the overall QPF and PoP with this approaching boundary, as the long-term model suites are not in complete agreement on timing, frontal speed, and the duration of the FROPA. The ECMWF is notably quicker with the frontal passage, leading to a suppressed PoP and lower QPFs compared to the GFS, which tracks the system slower, resulting in higher PoP and QPFs. Nonetheless, the overall trend supports an increasing potential for precipitation toward the end of the forecast period. Overall, the start of the forecast period will be characterized by sustained upper-level ridging and surface high pressure. Precipitation chances increase for Tuesday afternoon and continue through the end of the period. High temperatures will remain in the low to mid 80s through Tuesday, but with the approaching cold front and increased precipitation, temperatures are forecast to fall into the lower 70s for Wednesday and Thursday. Overnight minimum temperatures will follow this same trend, starting in the upper 50s to lower 60s before cooling significantly into the mid to upper 40s for Wednesday and Thursday night. && .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) ISSUED AT 1258 PM EDT FRI OCT 3 2025 Surface high pressure and upper level ridging will keep the TAFs sites VFR through the period. There will be some fog that develops once again tonight mainly in the sheltered valleys. The winds will remain light generally less than 5 knots at most sites. && .JKL WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...DJ LONG TERM...VORST/GREIF AVIATION...DJ