834 FXUS63 KLMK 111732 AFDLMKArea Forecast Discussion National Weather Service Louisville KY 132 PM EDT Thu Sep 11 2025
...Updated Aviation Discussion...
.KEY MESSAGES...
* Continued mostly dry and abnormally warm through the weekend into early next week. Highs in the upper 80s to low 90s.
* Potential for rapid onset drought and enhanced fire weather conditions continues to increase for mid-to-late September.
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.UPDATE... Issued at 1132 AM EDT Thu Sep 11 2025
Most of the region is under sunny skies this morning, with a few areas of mid-level clouds over portions of the Bluegrass. Temperatures have quickly warmed into the upper 70s and lower 80s across the area and are on track to reach the mid-80s to around 90 by this afternoon. While PWAT values are lower (around 1-1.1") this morning, sounding profiles suggest that a scattered cu field should develop over the next few hours, especially over southern KY. A stray shower can`t be ruled out this afternoon/evening, but given dry advection, would expect almost everyone in the area to remain dry today.
The forecast is on track at this time, with only minor changes to near-term grids.
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.SHORT TERM /THROUGH TONIGHT/... Issued at 353 AM EDT Thu Sep 11 2025
Weak shortwave trough continues to slowly work through southern KY into TN during the early morning with an isolated cluster of showers along the TN/KY border. This activity will continue to push southeast and out of the area before sunrise. Clearing across southern IN and north central KY has allowed for some very patchy fog to develop which will mix out as we go through the morning.
Upper ridging building out of the southern plains expands northward during the day as the shortwave trough continues to work eastward. Weak inverted sfc trough will be located across western KY, southern IL into southwest IN. This may be enough forcing to help fire off isolated pop up showers in the afternoon. Decided to go with a 10 percent PoP for the southern half of our CWA later this afternoon. With sfc high pressure to our north over Hudson Bay, most of the CWA will likely remain dry. With increasing heights thanks to the expanding upper ridge, temperatures continue to be warmer with highs ranging from mid/upper 80s to near 90 across our southwest.
Any activity should start to diminish with the loss of daytime heating as we go into the evening hours, skies will be mostly clear, winds will be light and lows will be in the mid/upper 50s to near 60. Patchy valley fog could once again form across the region.
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.LONG TERM /FRIDAY THROUGH WEDNESDAY/... Issued at 353 AM EDT Thu Sep 11 2025
Upper ridging will continue to expand northeastward from TX into the Ohio Valley and Great Lakes through the weekend and into early next week. Locked into this pattern, temperatures will continue to warm from the mid/upper 80s to near 90 on Friday to low 90s into the weekend and early next week. Return flow out of the south will remain limited as dewpoints stay mainly in the 50s through the weekend. With the unseasonably warm temperatures and lower dewpoints, combined with abnormally dry to even moderate drought conditions across central KY and southern IN, we will continue to see elevated fire weather concerns. With surface winds staying light, the concern of spreading is limited. With the prolonged dry weather expected through the extended forecast, the fire weather parameters will need to be monitored.
As for our next chance of precipitation, upper ridging looks to hold firm over the Ohio Valley and into the Great Lakes into the first half of next week. While a weak backdoor cold front is expected to drop southward Sunday night into Monday, the trend in the deterministic models is for this boundary to be moisture starved with very low PoPs associated with it.
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.AVIATION /18Z TAFS THROUGH 00Z SATURDAY/... Issued at 132 PM EDT Thu Sep 11 2025
Scattered cu field with cloud bases around 5-6 kft has developed over the area and should continue through the afternoon and early evening hours, dissipating around sunset. Winds this afternoon should be light, 10 kt or less, out of the N/NE. Tonight, light and variable winds are expected, with VFR conditions expected to continue at all sites until the immediate pre-dawn hours Friday. Depending on how much dry air mixdown occurs this afternoon, near- sfc moisture may be great enough for MVFR/IFR vsbys in fog, especially at BWG. Any fog should quickly dissipate after sunrise, with VFR conditions and light E/NE winds expected on Friday.
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.LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None.
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UPDATE...CSG SHORT TERM...BTN LONG TERM...BTN AVIATION...CSG
NWS lmk Office Area Forecast Discussion