507 FXUS63 KJKL 251855 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 255 PM EDT Tue Jul 25 2023 .SHORT TERM...(This evening through Wednesday night) Issued at 255 PM EDT TUE JUL 25 2023 Present surface analysis has the forecast area under a regime of surface high pressure that's situated across the eastern CONUS. As a result, warmer temperatures will be advected in. Also, aloft, the forecast area sits at the base of a longwave trough that could favor a few afternoon/evening thunderstorms. Those storms will likely dissipate toward sunset. Valley fog is expected overnight tonight as clear skies will be in place and river valleys can saturate. Also, wherever it rains, fog will also be possible. A shortwave trough is expected to develop overnight over Wisconsin and eject toward the Great Lakes and the Ohio Valley. At the surface, a surface low will move along the Ohio/Michigan state line with a warm front lifting through the Commonwealth. Along the front, showers and thunderstorms will be possible late Wednesday evening into overnight Wednesday. Supporting severe weather dynamics are closer to the low and timing of the front is unfavorable; therefore, severe weather for eastern Kentucky will be limited but not zero. Any remaining showers and storm will dissipate through the overnight as high pressure slowly works back into the region. .LONG TERM...(Wednesday night through Monday) Issued at 507 AM EDT TUE JUL 25 2023 Key Points: * Uncomfortable, potentially dangerous heat is expected during the first few days of the long term period. Highs will rise into the low to mid 90s with heat indices in the upper 90s and low 100s. * Most of the area remains dry through Friday with only pop-up showers and storms expected. A cold front approaches the area Saturday int Sunday and will bring the best chance for precipitation during the period. The long term will start out Wednesday night with a large upper ridge centered over the eastern Four Corners region and will dominate a good portion of the CONUS to start as it spans from off the Baja California peninsula to the Southeast. Elsewhere across North America, several disturbances will impact Canada and the northern regions of the CONUS while a Bermuda ridge stretches toward the Southeast. The two ridges will try to build into each other but disturbances dropping in from Canada should keep this from occurring. Models depict a large trough dropping southward along the west coast which will nudge the western ridge towards the heart of the CONUS toward the end of the period. A shortwave disturbance will dig into the upper Great Lakes late this week and into the weekend and will bring a cold front through the Ohio Valley. Models disagree on timing and exact evolution of this feature but regardless, this will likely be the best chance for precipitation across the Commonwealth. Sensible weather will be hot and muggy to start with pop-up showers and storms possible each afternoon and evening. The warmest conditions of the season are expected Thursday through Saturday with highs peaking in the low to mid 90s each afternoon. Dew points in the upper 60s to low 70s will produce uncomfortable and possibly dangerous conditions with heat indices reaching into the upper 90s and into the low 100s. Friday is expected to be the warmest day with heat indices approaching the heat advisory criteria of 105. PoP up showers and storms will be possible Thursday and Friday, though most of the area will remain dry. The best chance for precipitation will come Saturday and Sunday as a cold front approaching the area provides ample forcing across the area. Model solutions do show some disagreement in the evolution of this pattern so remained close to the NBM solution for PoPs. Highs are expected to "cool-off" into the upper 80s Sunday and Monday but high dew points will keep the mugginess around. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) ISSUED AT 127 PM EDT TUE JUL 25 2023 MVFR/VFR CIGS are presently in place as a deck of cumulus has developed across the area. As temperatures continue to warm, that cloud deck will gradually increase to VFR. Areas of showers and thunderstorms are possible this afternoon but confidence in the location of those storms is very low; therefore, left it out of the TAF. Any shower or storm is expected to dissipate toward sunset. Light and variable winds are expected through the period with valley fog developing at KSME around 03Z/Wed. Fog is forecast to burn off around 13Z and terminals will be largely VFR through the remainder of the TAF period. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...VORST LONG TERM...BATZ AVIATION...VORST