869 FXUS63 KJKL 161056 AFDJKLAREA FORECAST DISCUSSION National Weather Service Jackson KY Issued by National Weather Service Wilmington OH 656 AM EDT Tue Sep 16 2025
.KEY MESSAGES...
- Mainly dry weather will persist through Saturday morning.
- Temperatures will continue to be above normal through Saturday.
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.SHORT TERM...(This evening through Wednesday) Issued at 656 AM EDT Tue Sep 16 2025
09Z sfc analysis shows high pressure over the eastern Great Lakes stretching south through the spine of the Appalachians Lower pressure is found riding up the Mississippi River and western Ohio Valley and another large area along coastal Carolina. For the most part, eastern Kentucky is staying dry and relatively cloud free this night with just some high ones drifting in from the east and a smattering of lower clouds to the southwest. In addition, the river valley fog shows up clearly on satellite early this morning. These conditions also set up another decent night of radiational cooling with a small ridge to valley temperature difference underway as readings currently vary from the upper 50s in a few of the sheltered locations to the low and mid 60s in the thermal belt region on the hilltops. Meanwhile, dewpoints are running in the min 50s to lower 40s most places.
The models, and their individual ensemble suites, remain well aligned with each other aloft through the short term portion of the forecast. They all depict a closed low trough over eastern North Carolina and another area of troughing centered near Yellowstone with a narrowing ridge between these features stretching over the Great Lakes. The eastern trough will gradually slip off to the northeast and start filling while the ridging weakens to our northwest on Wednesday, During this time, some mid level energy will slip pwat into our area from the eastern trough. The small model spread through the period supported using the NBM as the starting point for the forecast grids again this morning with minimal adjustments needed mainly just to tweak the forecast this afternoon by adding some details from the latest CAMs consensus guidance. Did also include a enhancements in the temperatures temperatures for the area tonight some terrain.
Sensible weather features our warm weather pattern continuing for most of the area with slightly cooler conditions in the east with more and thickest cloud cover anticipated due to the upper trough and sfc low to the east. Again there will be enough moisture and upper level support around to allow for a few pop-up showers and stray thunderstorm in the Cumberland Valley nearer to the Tennessee border this afternoon during peak heating. Anticipate another similar night compared to this night heading into Wednesday morning with a ridge to valley temperature split and mainly just some river valley fog. Wednesday looks like another warm day with minimal threat for any convection as the upper levels become less favorable, winds will be light through the period away from any of the potential thunderstorms this afternoon.
The changes to the NBM starting point were again primarily focused on adjusting the Pops per the latest CAMs consensus and keeping just enough to mention for the afternoon in the far southern portions of the CWA. Temperatures were not changed much aside from enhancing ridge to valley difference tonight.
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.LONG TERM...(Wednesday night through Monday) Issued at 656 AM EDT Tue Sep 16 2025 The main changes to the extended forecast on this shift were to push the better Pop and thunder chances back another 12-24 hours until later to the weekend. Did also continue the terrain based adjustments for temperatures each night through the rest of the week.
The previous long term discussion follows:
By Wednesday, the upper-level low off the mid-Atlantic will transition from a distinct closed low to an open shortwave. This shortwave will be absorbed into a deepening longwave trough well to our northeast in the Labrador Sea from Wednesday night into the weekend. To our west, the polar jet remains ridged well into central Canada through the end of the week. An upper-level shortwave will be settled in the northern Missouri River Valley by Wednesday morning, with weak zonal flow keeping its eastward movement minimal through the week and into the weekend.
Models remain in good agreement about the pattern through Thursday, and have been persistently trending towards a later and later arrival time of the shortwave trough this weekend. Cluster analysis of WPC and LREF data reveals that the model variability doesn`t increase until Friday, and even then the primary forecast uncertainty results from differences in amplitude of the developing trough well to the north and out of the sphere of influence of our forecast area. NBM PoPs reflect the trend towards further slowing of the mid-country system, keeping PoPs
NWS JKL Office Area Forecast Discussion