222 FXUS63 KLMK 141931 AFDLMKArea Forecast Discussion National Weather Service Louisville KY 331 PM EDT Tue Oct 14 2025
.KEY MESSAGES...
* Dry conditions are expected through the rest of the workweek with highs mostly in the 70s.
* Strong frontal boundary to move through the region late Saturday and into Sunday. Strong thunderstorms will be possible during this time frame with 1-2 inches of rainfall.
* More dry weather to follow for early next week.
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.SHORT TERM /THROUGH WEDNESDAY/... Issued at 328 PM EDT Tue Oct 14 2025
It is a very pleasant day across the region, with sfc high pressure and upper ridging dominating the weather for us. Temps are in the mid to upper 70s, though a few isolated spots hitting 80 are beginning to show up on the KY Mesonet map despite breezy NE flow. By this evening, winds will relax, leading to a nice night with mostly clear skycover and temps dropping into the upper 40s to low 50s. With light winds and clear skycover, we could see some patchy fog develop in the early morning hours, especially in the river valleys.
For tomorrow, mostly sunny conditions are anticipated, though a very weak and moisture-starved cold front looks to drop south through the region during the day. Hi-res guidance suggests maybe a few light showers well north of our area, but our atmospheric profile will be dry enough to not have any precip mention. We`ll likely see temps range some from north to south across the forecast area, with the Bluegrass region limited to the low 70s, but approaching 80 across south-central KY.
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.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... Issued at 328 PM EDT Tue Oct 14 2025
===== Wednesday Night - Friday Night =====
Amplified upper ridge will build over the eastern US for the second half of the work week, which will continue to influence dry and sunny weather for the Ohio Valley. Temps will be near normal on Thursday, though could be slightly warmer on Friday as we tap into WAA regime with the sfc high shifting off to the East Coast. Clouds will also be on the increase for Friday, which could play into a lower confidence on high temps for the day.
===== Heavy Rain This Weekend =====
By Saturday, the upper ridge axis will slide east of the region, opening the door for a pronounced digging upper trough over the central US to shift eastward. Though the sfc low will be tracking across southern Canada, the trailing cold front will be quite strong as it trails extensively into the southern Plains. The sfc pressure gradient out ahead of the cold front will be tightening, leading to gusty southwest winds before any rain arrives. This SW flow pattern will ramp up the WAA regime, leading to temps to likely hit the upper 70s and low 80s, along with rising dewpoints as we begin to tap into a deeper Gulf moisture fetch. We could see rain showers begin entering the CWA from the west by Saturday afternoon, but the best forcing and most moisture arrives for Saturday night.
By Saturday night, the LLJ increases ahead of the approaching cold front, possibly exceeding 45kts in the 850mb layer. This will further ramp up the moisture transport axis across our area, leading to PWAT values approaching 1.6". The 100-member LREF indicates a 30% chance for PWATs exceeding the 1.6" threshold, which would be around the daily max for sounding climo from BNA for this time of year. However, the question remains how much of the jet core will make it down to the sfc overnight if a nocturnal inversion can hold. Regardless, our forcing and moisture will be maximized through Saturday night ahead of the cold front, leading to a line of moderate to heavy rainfall and embedded thunderstorms passing through the area. A widespread 1-2 inches of rain is expected, though locally heavier amounts will be possible. We may see some localized flooding issues, but the residence time of moderate rain appears to be short enough to limit widespread flooding concerns.
There also exists a low-end severe risk for our area, but as mentioned in prior discussions, the timing of the cold front being overnight could play in our favor for mitigating severe risk. The best chances will be along the Mississippi River, and western KY, as highlighted by the SPC D5 outlook. The NSSL ML guidance outputs a 10% chance for total severe probs, with a 15% across western KY and southern IL/MO. Model soundings show a high shear low CAPE environment, which should be no surprise given the racing LLJ overhead during the nighttime hours.
By Sunday morning, the cold front will be sliding east of the I-65 corridor. Additional showers and storms will be ongoing throughout Sunday as well, though the LLJ core and moisture transport axis will be sliding east with the front, leading to less forcing and moisture. In a post-frontal regime, combined with heavy cloud cover, temps on Sunday will be limited to the 60s. The upper trough axis will eventually clear east of the area by Sunday afternoon/evening, which will result in decreasing cloud cover later in the day.
===== Early Next Week =====
The upper trough deepen into a closed low over the Mid-Atlantic by Monday, though ridging will be building across the Midwest. We`ll have sfc high pressure extend up into the TN Valley for next week, which will keep a dry forecast. Temps will be near normal with highs right around 70, and lows in the 40s.
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.AVIATION /18Z TAFS THROUGH 00Z THURSDAY/... Issued at 129 PM EDT Tue Oct 14 2025
VFR conditions are ongoing across the region, and are expected to continue throughout the forecast period. Breezy northeast winds this afternoon will relax by this evening. Some patchy fog may develop in the valleys overnight, but currently do not expect the terminals to be impacted.
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.LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None.
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SHORT TERM...CJP LONG TERM...CJP AVIATION...CJP
NWS LMK Office Area Forecast Discussion