828 FXUS63 KLMK 161417 AFDLMKArea Forecast Discussion National Weather Service Louisville KY 1017 AM EDT Tue Sep 16 2025
.KEY MESSAGES...
* Mostly dry weather is expected over the next week, with ongoing abnormally dry and moderate drought conditions likely to persist.
* Temperatures will be unseasonably warm with highs in the upper 80s to the lower 90s.
* Rain chances return for the weekend, but rainfall amounts are expected to be light.
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.UPDATE... Issued at 1017 AM EDT Tue Sep 16 2025
Skies are partly sunny this morning, with a combination of SCT mid- level clouds developing overhead and thin cirrus spreading overhead from the east. A weak inverted sfc trough remains over south-central KY this morning, where slightly more moisture is pooled. Weak low- level convergence, as well as modest destabilization (500-1000 J/kg MLCAPE), could result in the development of isolated showers in southern KY this afternoon. This area is seeing quite a bit of sunshine this morning, which will allow the low level lapse rates to steepen quickly. Any cells that do develop should be fairly sparse, and this isolated activity should mostly sink south of the TN border by 23-00Z this evening.
Otherwise, the vast majority of folks will continue to enjoy dry, warm weather the rest of the day. Temperatures are warming into the low to mid 70s this morning, with a few cool spots still lingering in the upper 60s. Temperatures will again top out in the upper 80s and lower 90s during the mid to late afternoon hours.
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.SHORT TERM /THROUGH TONIGHT/... Issued at 257 AM EDT Tue Sep 16 2025
Today features a Rex block pattern over the eastern US, with an upper ridge over the Great Lakes and an upper low over the Carolinas. Moisture associated with the low will shift slightly west today, and we`ll see an increase in upper level cloud cover as a result. Temps today could end up being a bit tricky due to how much of an impact these clouds will have on heating, but generally think upper 80s to lower 90s are most likely.
Additionally, a weak inverted sfc trough over the region today may provide just enough of a trigger for some isolated showers or storms to pop up this afternoon across south-central KY, as seen in some of the CAMs. For what it`s worth, SPC has included south-central KY in a general thunder risk for today. Lapse rates will be steep, and should have a decent amount of instability due to our heating, though little to no shear. The question remains how much moisture will be available. We should have fairly deep mixing, resulting in a rather deep dry layer that would be an inhibiting factor for PoPs today. Will continue with the previous forecast and keep any PoP mention below 15%, which is essentially a dry forecast.
Upper level clouds will linger into the overnight hours, though dry weather is expected. We could see some patchy fog in the valleys, but confidence is not high as of now. If we do end up with some isolated precip across south-central KY, that could end up favoring some fog development. Otherwise, temps are forecast to drop into the upper 50s to low 60s overnight.
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.LONG TERM /WEDNESDAY THROUGH MONDAY/... Issued at 257 AM EDT Tue Sep 16 2025
===== Wednesday through Thursday Night =====
The upper pattern will feature mid-level lows to the east and west of the area on Wednesday, with mid-level ridging over the Midwest. We`ll see this ridge continue to sit over the area for Thursday as the East Coast mid-level low departs off the coast, taking any moisture with it. This will continue the hot and dry period toward the end of the week.
High temps for both Wednesday and Thursday are forecast to hit the upper 80s to lower 90s, but given how much temps overachieved Monday, these highs could end up slightly higher. Fortunately, low dewpoints will help keep heat indices from becoming excessive.
===== Friday through Monday =====
The upper ridge becomes more centered over the Ohio Valley on Friday as a deepening upper trough moves over the central US. Expect Friday to remain dry as the trough remains to our west, with temps expected to hit the lower 90s once again.
We welcome rain chances back to the region by Friday night and especially for the weekend as the upper trough and associated forcing eventually pivot across the Ohio Valley. Our best rain chances will come Sunday as slightly richer moisture and forcing overlap, though overall precip looks to be rather light. Rain chances will continue into Monday as well.
Increased cloud cover and scattered precip will help lower our forecast highs over the weekend, with upper 80s on Saturday, but mid 80s for Sunday and into Monday.
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.AVIATION /12Z TAFS THROUGH 18Z WEDNESDAY/... Issued at 635 AM EDT Tue Sep 16 2025
VFR conditions will continue today. Satellite imagery shows upper level clouds drifting in from the east this morning, and expect cloud cover to increase through the day. Light winds will be mainly from the E-NE today. Some high base cu development is possible this afternoon during peak heating, along with a few stray showers near BWG. However, confidence in precip is too low to mention in TAF at this time.
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.LMK WATCHES/WARNINGS/ADVISORIES... KY...Air Quality Alert until midnight EDT tonight for KYZ029>031. IN...Air Quality Alert until midnight EDT /11 PM CDT/ tonight for INZ076>079-083-084-089>092.
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UPDATE...EBW SHORT TERM...CJP LONG TERM...CJP AVIATION...CJP
NWS LMK Office Area Forecast Discussion