663 FXUS63 KLMK 151639 AFDLMKArea Forecast Discussion National Weather Service Louisville KY 1239 PM EDT Mon Sep 15 2025
.KEY MESSAGES...
* Mostly dry weather is expected over the next week. With most of the region experiencing abnormally dry or moderate drought conditions already, many counties have burn bans in place at this time.
* 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 1238 PM EDT Mon Sep 15 2025
A weak, wavy frontal boundary is draped southeast through the region early this afternoon. However, a much richer moisture plume is noted off to the west, extending north through AR, MO, IA, and MN. This is downstream of an area of low pressure lifting northeast across ND. This system will continue to peel off to the northeast into Canada, with mid and upper level ridging remaining in place over the Great Lakes. This upper level ridging just off to our north and west is contributing to dry NE flow aloft and notable mid-level subsidence. We`ll likely see SCT cumulus to continue developing this afternoon, but showers are unlikely. A rogue shower or two is not completely out of the question, but most will remain dry.
Temperatures continue to warm into the mid/upper 80s under mostly sunny skies. Temps are on track to top out in the upper 80s and lower 90s this afternoon.
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.SHORT TERM /THROUGH TONIGHT/... Issued at 254 AM EDT Mon Sep 15 2025
A weak frontal boundary is across the area this morning, which has been the driver for some isolated showers to develop in western KY along the better PWAT axis. Expect precip to remain to the west of our area this morning since we have drier air, but can`t completely rule out a stray shower this morning in the southwestern corner of the CWA. Will keep PoPs below 15%, so no mention of precip in the forecast at this time.
Upper level flow features an Omega block pattern over the US today, with ridging over the Midwest, and troughing to our east and west. This pattern will shift more into a Rex block by tonight as the upper ridge moves north of the eastern trough, closing it off over the southeastern US. We will be under the ridge for today, which will lead to dry conditions and temps above normal again. Highs for this afternoon are forecast to peak in the upper 80s to lower 90s.
Dry weather continues tonight, with perhaps some overnight upper level cloud cover streaming in from the east from the southeastern US upper low. Guidance signals we could have some smaller dewpoint depressions across south-central KY before sunrise Tuesday, so we may have some patchy fog in areas south of the Parkways tomorrow morning, but confidence in this remains low. Temps in the 60s expected overnight.
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.LONG TERM /TUESDAY THROUGH SUNDAY/... Issued at 254 AM EDT Mon Sep 15 2025
===== Tuesday through Thursday Night =====
The upper level pattern will continue to feature a Rex block pattern for the mid-week, with an upper low over the southeastern US, and ridging to the north. An associated sfc low will be located over the mid-Atlantic coast, and is expected to keep most of any associated moisture over an area stretching from South Carolina to Pennsylvania and New Jersey. Thus, our area remains in a drier airmass, with no considerable precip chances for this portion of the long term period. Some guidance does indicate some isolated radar returns Tuesday afternoon across portions of southeastern and south-central KY, but soundings reveal dewpoint depressions around 30 degrees, which would be a fairly deep and dry layer that any precip would have to get through to make it to the sfc. The Rex block pattern will break down by Wednesday into Thursday. Daytime highs will range from the upper 80s to lower 90s for Tuesday through Thursday. However, with dewpoints only reaching the upper 50s to low 60s, this will help keep our heat index values closer to the sensible temps. Of these three days, Tuesday has slightly lower forecast highs due to expected increased cloud coverage drifting over the region from the upper low to our southeast.
Across most of the region, we`ll see a negative feedback loop here with the continued dry and warm temperatures resulting in a continued dry out of surface fuels. This could result in an elevated fire weather risk across the region. The ongoing dryness has already led to burn bans in several counties of southern Indiana and central Kentucky.
===== Friday through Sunday =====
As we get to the end of the work week, the upper pattern could feature a stronger mid-level trough over the central US, with a closed low in the upper levels. The trend continues to signal a slower progression of the trough, resulting in a later arrival for precip to the region. Ensemble member view of both the GFS and Euro show members picking up QPF as we get into the weekend, with nearly no members showing QPF as early as Friday. The NBM seems to be catching on as well, with the latest run now delaying precip onset slightly.
With the upper trough essentially stagnant over the High Plains for Friday and some of Saturday, we will not receive a strong moisture fetch into the area. Mid-level vort wings extending out from the trough will likely provide some initial forcing over the area, which may be enough for some isolated to scattered precip by Friday afternoon and evening, but we do not have any QPF in the forecast until Friday night. Additionally, the better forcing will not arrive until Sunday when the trough finally pushes over the Great Lakes region. As such, PoPs will be higher for Sunday as we could actually end up seeing a bit more coverage in precip. Overall precip amounts are expected to remain light, possibly less than a quarter of an inch for the weekend. We`ll take any rain we can get, but as of now this wave does not look to overcome our current drought conditions.
With mostly dry weather now expected for Friday, temps may end up reaching the lower 90s. Clouds will be increasing on Saturday, resulting in slightly lower temps in the mid-80s. Sunday features low to mid 80s as even more cloud cover and precip play a role in our high temp forecast.
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.AVIATION /12Z TAFS THROUGH 18Z TUESDAY/... Issued at 642 AM EDT Mon Sep 15 2025
VFR conditions are ongoing across the area this morning, and expected to continue for the TAF period. Light winds will generally be from the east today, varying between SE and NE. Otherwise, expect some mid-level and high-level clouds today, but no impacts are to be expected. Some patchy fog may be possible at BWG tomorrow morning, but confidence remains low at this time.
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.LMK WATCHES/WARNINGS/ADVISORIES... KY...Air Quality Alert until midnight EDT Tuesday night for KYZ029>031. IN...Air Quality Alert from midnight EDT /11 PM CDT/ tonight to midnight EDT /11 PM CDT/ Tuesday night for INZ076-083-084- 089. Air Quality Alert until midnight EDT Tuesday night for INZ077>079-090>092.
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UPDATE...EBW SHORT TERM...CJP LONG TERM...CJP AVIATION...CJP
NWS LMK Office Area Forecast Discussion