Area Forecast Discussion
Issued by NWS Jackson, KY

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322 FXUS63 KJKL 140718 AFDJKL AREA FORECAST DISCUSSION National Weather Service Jackson KY Issued by National Weather Service Wilmington OH 318 AM EDT Mon Jul 14 2025 .KEY MESSAGES... - Warm/hot temperatures and high dew points will persist for the next week, resulting in sultry conditions. - There will be a daily potential for showers/thunderstorms over the next week, especially in the afternoon/evening hours. && .SHORT TERM...
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(Today through Tuesday) Issued at 318 AM EDT MON JUL 14 2025 A compact vort-max and it`s associated shortwave trough will weaken throughout the morning as it moves northeast across Ohio. Even with the vort-max weakening, the shortwave will still provide enough lift throughout the afternoon to aid in thunderstorm development. Based on area forecast soundings, mean flow remains quite weak, but it is aligned in the same easterly direction through the lower troposphere. Expect thunderstorm activity to move from west to east throughout the day, with some outflow interactions possible. Can`t rule out a locally strong downdraft resulting in wind damage, but this should not be very widespread. The activity weakens into the evening hours with locally dense fog possible within area valleys. Tuesday, another vort-max and weak shortwave will once again track northwest of the local area, with the trough axis slightly negatively tilted. This results in a bit more southwesterly mean flow with afternoon thunderstorms moving more southwest to northeast. Similar to Monday (today), not expecting much in the way of severe weather due to the generally weak flow. Wind shear is a little closer to 20 knots, but the thermodynamic is quite similar, with skinny CAPE profiles yielding 1500-2500 J/kg. For both days, above normal PWATs will provide opportunities for locally heavy rainfall, but this would be isolated to areas where outflow boundaries increase convergence and potentially slow storm motions. The local area is current in a Marginal Risk (level 1 of 4) for Monday. The slightly slower storm motions may support instances of back-building from east to west. .LONG TERM...(Tuesday night through Sunday) Issued at 310 AM EDT JUL 14 2025 No major updates from the Sunday afternoon issuance of the long term narrative which is below... Any thunderstorm activity ongoing Tuesday evening is expected to quickly weaken into the early overnight hours. Overnight low temperatures cool down towards 70 degrees. For the rest of the long term forecast period, the guidance suite collectively resolves a stagnant weather pattern over the eastern half of the country. A broad anticyclone is forecast to remain parked over the Southeastern states, whereas zonal flow will move through the Upper Midwest and into the Great Lakes. The Ohio River Valley will be situated between the two, and our sensible weather will accordingly be driven by characteristics of both. Southwesterly flow in the lower levels of the atmosphere will persistently advect a warm, moist airmass into the Commonwealth, keeping temperatures and humidity high. This will lead to above- normal PWATs and increasingly oppressive heat indices on Wednesday and Thursday. Expect afternoon highs in the low 90s on both days and peak heat indices in the upper 90s in the deepest valleys and urban corridors. These warm/humid conditions will combine with some shortwave impulses moving through the broader zonal flow to enhance precipitation chances across the area on Wednesday and Thursday. Thunderstorms will be possible, but they are likely to remain pulse-like in nature. Weak winds aloft and dry air in the column will mitigate deep-layer shear and thus the potential for highly-organized convection. This is particularly true for southern KY, which will be closer to the center of the southeastern ridging. Thus, the greatest sensible weather impacts over the area next week will likely come from the cumulative nature of the heat and the repetitive nature of the precipitation chances. Rain chances will peak every day in the afternoon/evening hours, and the heaviest showers could provide some localized relief from the hot apparent temperatures. However, overnight lows near 70 degrees will provide limited nocturnal relief. The NWS HeatRisk tool has been picking up on the potential for heat-related health impacts across Eastern Kentucky in the Wednesday-Thursday time frame. Likewise, WPC has outlined the forecast area in Marginal (Level 1/4) Excessive Rainfall Outlook on both Thursday and Friday. The potential for localized flash flooding will be highest in areas that see multiple rounds of heavy rain multiple days in a row next week, as soils in those places will progressively be able to absorb less moisture. Guidance suggests that the SE ridge may flatten late next week and allow a weak frontal boundary to slide into the forecast area. This could yield slightly cooler afternoon highs in the 80s, but a lack of deep upper level support means that said front is likely to stall out. This will keep diurnally-peaking rain chances in the forecast for next weekend, and we will closely monitor the potential for any potential excessive rainfall-related impacts as the mesoscale details of the forecast become clearer by mid-week. In short, expect an active summertime weather pattern to persist across Eastern Kentucky this week. Confidence is high that Eastern Kentucky will experience seasonably warm/humid conditions and daily diurnal peaks in shower/storm chances throughout the next week. Only minor adjustments were made to the NBM-populated long term forecast grids, as it is capturing the general pattern well. Confidence in the magnitude of overnight ridge-valley temperature splits is low due to the potential for lingering clouds from diurnal convection. Likewise, nocturnal fog may form in locations with wet grounds beyond the typical river valleys. With that being said, grid edits were limited to minor reductions in valley low temperatures, minor increases in ridgetop low temperatures, and the addition of valley fog in the weather grids.
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&& .AVIATION...
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(For the 06Z TAFS through 06Z Monday night) ISSUED AT 117 AM EDT MON JUL 14 2025 Scattered mid and upper level clouds continue to spread across the area late this evening potentially delaying the onset of valley fog. Pushed back the onset time a couple of hours for this latest forecast. Showers and storms are expected to return tomorrow and persist through much of the afternoon. Convection could bring decreased categories to terminals. Lastly, winds are forecast to be light and variable. For now, targeted 17-23Z as the primary window for convection with TEMPO groups possible if confidence grows by the 12Z TAF. Convective activity decreases during the evening hours with terminals VFR through 06Z.
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&& .JKL WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...ILN LONG TERM...MARCUS/ILN AVIATION...ILN