


Area Forecast Discussion
Issued by NWS Jackson, KY
Issued by NWS Jackson, KY
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905 FXUS63 KJKL 171732 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY 132 PM EDT Fri Oct 17 2025 .KEY MESSAGES... - Showers and thunderstorms arrive late Saturday evening/night lasting into Sunday. Any storms could produce strong wind gusts and torrential downpours. - Sunday wind gusts of 30 mph or greater are likely, with the probability of 40+ mph remaining at a 10 to 30 percent chance. && .UPDATE... Issued at 132 PM EDT FRI OCT 17 2025 Temperatures have been running a little cooler than prior forecast, so this afternoon`s high temperature values were nudged down a degree across most of the area -- anticipate highs to 69 north foothills to 77 near Lake Cumberland. UPDATE Issued at 1040 AM EDT FRI OCT 17 2025 Fog has lifted and dissipated across the eastern Kentucky Coalfields, leaving bright sunshine an a few high cirriform clouds. Look for high clouds to gradually increase in coverage from the southwest as we head through the afternoon. Still anticipate high temperatures in the lower to middle 70s this afternoon in most locations with a few upper 70s possible near Lake Cumberland. Hourly T and Sky cover forecasts have been brought into line with the latest observations; otherwise, forecast was still in good shape for the remainder of today. UPDATE Issued at 744 AM EDT FRI OCT 17 2025 Fog lingers in the river valleys and along the largest creeks while cirrus is passing overhead. This valley fog should lift and dissipate by the 9 to 10 AM timeframe. Otherwise, high pressure will bring a milder day today. && .SHORT TERM...(Today through Saturday) Issued at 555 AM EDT FRI OCT 17 2025 Early this morning, an upper level ridge extended from the Caribbean across the Gulf tot he Lower OH Valley to western Great Lakes to western Ontario. Meanwhile, an upper level ow was centered near the border area of ND with Saskatchewan and Alberta with a trailing 500 mb trough axis into the Great Basin to southern CA and into the Pacific. At the surface, high pressure was centered over the mid to upper OH Valley region. Locally, fog has formed along the river valleys and along some of the largest creeks and area lakes with this generally more widespread in the KY and Big Sandy River basins. Per KY Mesonet and home weather station networks temperatures have dropped to as low as 36 to 39 where fog has not been present or only transient while temperatures at 5 AM ranged through the 40s to around 50 elsewhere. Today, the upper level ridge axis should shift east to the Caribbean to FL to the Southern Appalachians to eastern KY to central and eastern Great Lakes. At the same time, the sfc high pressure ridge should shift toward the eastern seaboard. Further west and northwest, the upper low should track into Ontario and begin to merge with another trough working across western Canada while a shortwave trough axis moves into the Upper MS Valley to Central Plains and another shortwave track to the Four Corners to Baja region and anther shortwave reaches the Northern Rockies/MT. Meanwhile, an associated sfc low should reach far western Ontario this evening with an initial cold front extending south into the Upper MS valley to Central to Southern Plains while another more substantial cold front drops south of the US/Canadian border into ND to MT. Locally, initial river valley fog should lift and dissipate through about 2 to 3 hours past sunrise or the 9 to 10 AM EDT timeframe. Otherwise, the airmass should moderate today with the sfc high departing to the east while dewpoints change very little. This should result in humidity falling to near or below 30 percent in several locations this afternoon. Winds will be light, however. Tonight and Saturday, The axis of the upper level ridge will move east to near the eastern seaboard. Meanwhile, further west, shortwaves should begin to merge into a developing trough over the Central Conus/Plains as the pattern amplifies and the 500 mb trough axis approaches the MS Valley. The initial cold front should more or less merge with the secondary colder push with the boundary reaching the western Great LAkes to mid MS Valley to TX and OK panhandles regions by Saturday evening. Locally, valley fog should again be a feature along the river valleys, the largest creeks, and area rivers tonight. Lows however should be 5 to 10 degree milder compared to current readings. Otherwise, return flow and warm advection ahead of the front will lead to a further moderation in temperatures for Saturday, with highs forecast in the low to mid 80s for elevations below 2000 feet. Dewpoints should reach the 50s with PW climbing to 1 inch and above for further west and northwest locations and above the 80th percentile climatologically per 00Z LREF. However, rain chances should hold off until the start of the long term period. .LONG TERM...(Saturday night through Thursday) Issued at 555 AM EDT FRI OCT 17 2025 The upper level trough axis should move to the MS Valley region Saturday night while a lead shortwave is expected to move across the Commonwealth. At the surface, the associated cold front should reach MI to Central KY to the Lower MS Valley by dawn on Sunday. The system will be quite dynamic with the 500 mb trough negatively tilted as it crosses the Commonwealth on Sunday and then departs to the east and northeast on Sunday night. Moisture will increase ahead of the approaching trough axis and cold front Saturday night and into early Sunday with PW poised to peak in the 1.1 to 1.4 inch range or around 83rd to 93rd percentile per 00Z LREF mean. Instability will be quite limited near and ahead of the front with 00Z LREF mean generally peaking at 100 to 200 J/kg, however, winds aloft will be quite swift and bulk shear should peak on the order of 40 to 50KT. Showers and any storms should move quite quickly and what storms that manage to form and/or a potential convective line near or in advance of the front will pose a threat of strong wind gusts. Outside of storms, momentum transfer suggests the potential for wind gusts of at least 30 to 35KT or possibly nearing the lower end of wind advisory criteria. for Wind gusts in particular and to an extent sustained wind magnitudes blending toward the 90th percentile of the NBM as bias correcting in the deterministic washes out the probability of stronger wind gusts with a rather dynamic system. Brief heavy downpours should also occur with any storms. Moisture decreases Sunday evening into Sunday night with the PW progged to fall to around 0.5 inches and drop a bit more into Monday as an upper level ridge works from the Central Conus into the OH Valley to Southeast with a ridge of surface high pressure preceding it across the Southeast and into the OH Valley. Depending on how quickly the pressure gradient relaxes on Sunday night and skies clear valley fog could become a concern following the anticipated rainfall this weekend. The pattern will remain somewhat zonal/active into the middle of the week with another upper low and associated trough progressing from the Central Conus to the Great Lakes and eastern Conus from Monday to Wednesday as the departs to the east. This system will have less moisture to work with though a few showers are possible late Monday night into Tuesday. Brief ridging/500 mb height rises are progged for late Tuesday night into Wednesday night or early on Thursday. Sfc high pressure should build into the Lower OH Valley from the Mid to Lower MS valley late Tue night into Wednesday, with the sfc high gradually shifting east late Wednesday night into Thursday. Some of the typically colder spots could drop to readings that could support patchy frost for Wednesday night. This potential was not added to the HWO as of yet as confidence is low and the main forecast concerns at this point are associated with the front over the weekend. && .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) ISSUED AT 132 PM EDT FRI OCT 17 2025 High pressure will dominate through the period as it gradually departs to the east. VFR conditions were prevailing at TAF issuance and will continue through the period, except in sheltered river valleys (e.g K1A6 and KBYL, and KI35) where MVFR or worse visibility reductions are possible in the typical fog late tonight. Light and variable winds will prevail through the period. && .JKL WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...GEERTSON SHORT TERM...JP LONG TERM...JP AVIATION...GEERTSON