textproduct: Louisville

KEY MESSAGES

* Waves of rain showers, with a few embedded storms, are expected this evening and into the overnight. Severe weather and flooding remain unlikely with this system. Though a few strong storms will be possible over far southern Kentucky.

* The late weekend into early next week will see drier weather conditions. Another chance of showers and possible storms will arrive late Monday and continue through all of Tuesday.

* Cooler shot of air will arrive for Thanksgiving Day.

UPDATE

Issued at 1011 PM EST Fri Nov 21 2025

Current forecast for the overnight into early morning looks to be on track. Main sfc low is working into western KY and will continue to push through the area overnight. KLVX is showing the development of showers across the northern half of the CWA and as the low moves across additional showers and even a few embedded thunderstorms look to increase further south. While SPC still has us under a Marginal outlook across our far southern CWA, agree with the previous forecast that the overall dynamics and instability are lacking for any substantial severe threat. That being said, a strong storm storm can't be entirely ruled out as the sfc low and frontal boundary push through the region.

The other impact tonight will be the development and ongoing low visibility from locally dense fog and drizzle. We will issue an special weather statement to account for these ongoing conditions and will monitor to see if a Dense Fog Advisory may be needed later. Other than that no changes expected at this time.

SHORT TERM /THROUGH SUNDAY/

Issued at 335 PM EST Fri Nov 21 2025

Afternoon satellite imagery shows mostly cloudy skies across the region, though we have some breaks in the clouds across portions of southeastern Kentucky. Afternoon temperatures were in the upper 50s across southern IN and across a good chunk of north-central and east- central Kentucky. Mid-upper 60s were found generally south of the Cumberland Parkway with readings along the KY/TN border pushing near 70. Area radars show a batch of more widespread showers lift northeast across northern Kentucky, with more scattered activity down across the south.

Low-amplitude shortwave trough axis across the deep south will move northeast through the TN Valley tonight. As this occurs, we expect additional showers and thunderstorms to develop within the warm conveyor belt from southern MO into TN and KY later this evening and overnight. Thunderstorms will likely be limited to areas south of the WK/BG Parkways. To the north of the Parkways, soundings show rather poor lapse rates aloft which will result in updrafts struggling. Even down across southern KY, lapse rates are pretty poor, but low-level hodographs are impressive still for mid-late November. A few strong storms can't be ruled out across far southern KY, mainly south of the Cumberland Parkway. The marginal risk is pretty generous across KY, but we really think the best threats of any strong storms will be along and south of the I-40 corridor in TN. Showers and storms will continue into the overnight hours as the surface low and frontal boundary slide eastward. Lows overnight will dip into the upper 40s over southern IN with low-mid 50s over KY. Behind the front, low-level temp inversion is likely to set up once again and a combination of low clouds and drizzle will be leftover behind the departing rainfall. Will have to watch obs tonight, but a period of dense fog could develop over southern IN and into portions of north KY later tonight and early Saturday morning.

For Saturday, mostly cloudy skies are likely across the region. Area averaged soundings from the NAM/HRRR show another inversion aloft developing which will likely trap moisture below it. So the chances of breaking out into partly cloudy skies looks much lower than it did 24 hours ago. Highs will range from the mid-upper 50s over the north to the lower 60s across the south. Drier air looks to finally work into the region by tomorrow night with lows falling into the upper 30s/lower 40s.

LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/

Issued at 335 PM EST Fri Nov 21 2025

Sunday through Monday...

Forecast continuity through this time period remains very good. Upper level ridging will build into the region from the west resulting in dry conditions on Sunday. Afternoon highs will range from the upper 50s to the lower 60s with overnight lows in the mid- upper 30s. Highs on Monday should be a little warmer with readings in the 60-65 degree range.

Monday Night through Friday...

By Monday night, a mid-level wave over the Plains will lift northeast and open up as it moves into the Great Lakes. This will drag a surface boundary through the region on Tuesday. Ahead of the front, we expect another round of widespread showers and possible thunderstorms beginning Monday night and then continuing into the day on Tuesday. The risk of severe weather remains quite low here as model lapse rates and instability are not overly impressive and the upper level wave is to be weakening as it moves into the Great Lakes. Nonetheless, some moderate to heavy rainfall will be possible here with another 1-1.25 inches of rain. Much of the rain looks to push east of the region on Tuesday, but the upper trough axis will lag behind. So cloudy conditions are likely to hang around Tuesday and into Wednesday as well. Highs Tuesday before the frontal passage will warm into the low-mid 60s, but look for highs in the upper 40s/lower 50s for Wednesday.

Clearing skies are expected by late Wednesday and a colder influx of air will arrive around that time. Lows Wednesday night will dip into the upper 20s, though protected valleys could hit the middle 20s. Cold cyclonic flow will remain in place for Thanksgiving day with high pressure moving through the region. Highs will likely feature a gradient across the region. Readings should top out in the lower 40s across southern IN and much of north central/east- central KY. Mid-upper 40s will be found south of the Parkways, with maybe some 50s along the KY/TN border. Lows Thursday night will be cold with upper 20s expected.

Friday will have to be monitored as a weak perturbation aloft may sneak into the northern portions of the region. This may bring some light snows well to our north with some light rain showers over southern IN/KY, with perhaps some lingering flurries Friday night.

Extended Forecast Discussion...

Moving into the extended period, earlier thinking on cold weather arriving sometime during the Thanksgiving Holiday period into late December is not likely to occur. Looking at the teleconnection pattern shows why. The expected pattern will be in a +NAO/neutral AO/-EPO/-PNA configuration. The original idea for late November cold was based on the NAO to be much more negative yielding sufficient blocking to get colder air into the US. A second reason is that the MJO looks to remain in phase 6 for the remainder of November which overall is a milder pattern.

While we will see a brief cool down near Thanksgiving, the pattern is expected to revert back to a milder pattern for the Ohio Valley. Given the MJO phase 6 and forecast teleconnection pattern with a weaker NAO blocking signal, a series of lake cutter systems with lows moving from the southern Plains into the Great Lakes will be seen. This will bring periods of unsettled weather to the Ohio Valley with above normal precipitation and risks of thunderstorms (some strong/severe). It would appear that we'll get a broad baroclinic zone setting up from the Plains to the Great Lakes. On the north side, widespread snows will help build the winter snow pack from the inter-mountain west into Canada and into the north- central and northern Plains. The overall pattern reminds me of December 2013, at least for the first half of that month.

Models have been insistent on a stronger westerly wind burst over the far western Pacific which should propel the MJO into Phase 7 as we head into December. This would favor much colder conditions on the north side of the aforementioned baroclinic boundary. Some south and eastward spread of the colder airmass across the Plains may become more evident, especially if stronger blocking can occur up near Greenland and more significant ridging builds in Alaska. Assuming the westerly wind burst does its job, the MJO should continue to propagate into phase 8 which would result in a more significant cool down as we get further into mid-December.

AVIATION /06Z TAFS THROUGH 12Z SUNDAY/

Issued at 1221 AM EST Sat Nov 22 2025

The main impacts through the forecast will be IFR and MVFR, with brief LIFR CIGs and VIS. We will also see a wind shift from the SW to more north as a front works through this morning. Low VIS from HNB-SDF-LEX will remain through the early morning with LEX/HNB dropping below 2 mile VIS with CIGs only a couple hundred feet. Slow improvement during the day to MVFR later in the day as we start to slowly clear out from the west to east but it may not really happen until late afternoon and into the evening. Once skies clear, VFR conditions will remain through the end of the forecast period.

LMK WATCHES/WARNINGS/ADVISORIES

KY...None. IN...None.