833 FXUS63 KJKL 180850 AFDJKLAREA FORECAST DISCUSSION National Weather Service Jackson KY 450 AM EDT Thu Sep 18 2025
.KEY MESSAGES...
- Mainly dry weather looks to persist through the weekend.
- Temperatures will continue to be above normal through this weekend and into next week.
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.SHORT TERM...(Today through Friday) Issued at 430 AM EDT THU SEP 18 2025
08Z sfc analysis shows high pressure over eastern Kentucky keeping winds light and skies mostly clear. These conditions have led to a good night of radiational cooling resulting in a moderate ridge to valley temperature split along with valley fog - locally dense but less extensive than last night. Temperatures currently vary from the mid 50s in the sheltered valley locations to the lower 60s on the hills. Meanwhile, dewpoints are running in the mid to upper 50s.
The models, and their individual ensemble suites, remain in excellent agreement aloft through the short term portion of the forecast. They all depict weak 5h ridging over Kentucky through Friday as the pattern re-orients itself with persistent troughing over the High Plains, a mainly north to south ridge through the Great Lakes, and deep troughing over the northeast quadrant of North America. The local ridge will also keep any energy at mid levels well away from the area through the period. The small model spread for the next few days continues to support the NBM as the starting point for the forecast grids with minimal adjustments needed - mainly just to include some terrain enhancements for temperatures at night.
Sensible weather features another couple of warm and dry days with more in the way of sunshine - once the initial morning valley fog clears out. Expect a similar night compared to this one heading into Friday morning with a moderate ridge to valley temperature split and fog confined mainly to the river valleys. Winds will be light through the period thanks to the sfc high pressure holding in place.
The changes to the NBM starting point were primarily focused on enhancing ridge to valley temperature differences tonight. As for PoPs, they were kept in the low single digits to near zero through the period - in line with the CAMs and MOS guidance.
.LONG TERM...(Friday night through Wednesday) Issued at 450 AM EDT THU SEP 18 2025
Again, the main changes to the extended forecast on this shift were to enhance the terrain based differences for temperatures each night through the weekend. The PoP chances starting the new work week appear to be stabilizing per recent model trends.
The previous long term discussion follows:
Highly amplified flow across North America continues into next week. An energetic system arrives on the West Coast on Sunday and continues progressing east through the week, absorbing a cutoff low in the central US into a larger troughing pattern by Tuesday, according to this morning`s model suites. When this trough eventually gets kicked and begins moving, it would be the source of the next set of widespread precip chances.
The biggest question of the forecast is whether to trust guidance that the pattern will actually be in motion by Tuesday. Overall ensemble guidance is in very good agreement, both with other ensembles as well as in run-to-run consistency, about the progression (or lack thereof) of the upstream pattern through Sunday, though run-to-run indicates a continued slowing bias.
Sunday, or the Day 5 and beyond timeframe, is when uncertainty becomes readily apparent regarding how/whether the upstream cutoff low will actually begin moving. For the last 4-5 days, models have struggled to capture the evolution of the ongoing pattern and this shortwave beyond FH96, pushing PoP increases in eastern Kentucky back by another day for each day that passes, consistently keeping "rain chances" at the periphery of the extended forecast. This trend will continue with each subsequent forecast until global models regain skill with the upstream waves impacting the West Coast. Thus, NBM PoPs have not been changed, with chances
NWS JKL Office Area Forecast Discussion