textproduct: Louisville

KEY MESSAGES

* Unsettled weather is likely to return later Thursday, with waves of showers and thunderstorms likely Thursday through Saturday morning.

* A few strong to severe storms could materialize Thursday evening or night, but confidence is low. 1 to 2" of rainfall expected through Saturday.

* Influx of colder weather is expected for the late Saturday and Sunday before temperatures moderate a bit into next week.

SHORT TERM /THROUGH WEDNESDAY NIGHT/

Issued at 312 PM EST Tue Jan 6 2026

Afternoon satellite imagery shows clearing skies moving into southwest IN and western KY this afternoon. Southwest winds continue across the region with gusts of 20-25 mph being observed. Where skies have cleared, temps have spiked into the low-mid 60s. Under the clouds, temperatures were still in the upper 50s. The low- level jet axis will move across central and eastern KY this afternoon. As the clearing skies work east, there may be a period of overlap where deeper mixing may occur and we could see some wind gusts into the 30-35 mph range this afternoon before winds die off after sunset.

For tonight, cold frontal boundary will push through the region and bring an influx of cooler air to the region. Lows tonight will range from the mid 30s over southern Indiana to around 40 across the central areas of our region. Down in the SE areas (Lake Cumberland) look for lows in lower 40s.

Dry weather is expected for Wednesday and Wednesday night as high pressure moves across the region. Highs on Wednesday look to warm into the mid-upper 50s with some 60s down along the KY/TN border area. Lows Wednesday night will range from the upper 30s to the lower 40s.

LONG TERM /THURSDAY THROUGH TUESDAY/

Issued at 312 PM EST Tue Jan 6 2026

Thursday through Saturday Night...

An unsettled period of weather is likely for late Thursday through Saturday as a powerful trough axis moves from the Plains through the Ohio Valley. Thursday will start off mostly dry with mild temperatures within a warm advective pattern. Surface low will move from the central Plains into the Great Lakes during the day. While this occurs, a warm front will lift northward through the region and will place our area in the warm sector during the afternoon/evening. A strengthening pressure gradient will allow the wind field to come up as well with gusty southwest breezes being seen in the afternoon. Wind gusts of 30-35 mph, may be up to 40 mph in spots will be possible as temperatures warm into the low-mid 60s over the northern half of the forecast area with upper 60s to near 70 down along the KY/TN border. The warm advective pattern will also allow moisture to pool up into the region with dewpoints rising into the mid-upper 50s.

By Thursday night, a low-level jet axis will work into the Ohio Valley from the west with speeds of 55-60kts. Shear with this system is quite impressive and similar to what we've seen in the December 2025 events. Model soundings show low-level SRH values jumping up to 250-350 m2/s2 while 0-3km SRH rises up into the 450- 500 m2/s2 range. Model soundings continue to show very little instability. However, as we've seen in the earlier events, all you need around here to get some severe is just a few joules of CAPE and plenty of shear to get mesovortices in linear/bowing structures.

It still appears that initial convection will be scattered in nature and will likely not increase in areal coverage until late Thursday evening. However, global models suggest that a more organized linear mode may develop with convection out to the west which will move through the region overnight. As we go through the late evening and the overnight, the wind shear field become more uni- directional with time. So, initial threats may be wind damage and mesovortices, but may evolve into a wind damage threat with bowing segments overnight.

As we move into Friday, convection is expected to push eastward through the region and push off to the southeast during the morning hours. Actual frontal passage may occur Friday morning or into Friday afternoon with a period of dry weather developing. This will be short-lived however as a secondary upper level wave ejects northeastward into our region late Friday which should result in another slug of widespread rain showers moving through the region Friday night and into the day on Saturday. Rainfall amounts through this period will generally be in the 1.5 to 3 inch range. As of this writing, we should be able to handle that without much issue. Of course, ponding of water on roadways and temporary fill ups of ditches and streams could occur during the rainfall events.

Secondary surface cold front will then surge into the region Saturday afternoon with temperatures falling quite rapidly in the wake of the front. A weak vort max looks to drop into the region Saturday night and may bring some snow showers to the region before departing off to the east early Sunday morning.

Sunday through Tuesday...

Large upper trough axis looks to swing east of the area on Sunday with an influx of colder air rotating from the Midwest into the Ohio Valley. Highs on Sunday will generally be in the mid 30s over southern IN and north Kentucky with upper 30s to around 40 down along the KY/TN border. Lows Sunday night will fall into the lower- mid 20s. A few of the valley locations could drop into the upper teens. Flow will flatten out a bit for Monday and Tuesday with dry conditions continuing. Look for highs on Monday to moderate a bit with readings in the lower-mid 40s over southern Indiana and northern Kentucky. Southern Kentucky looks to see temps warm back in to the upper 40s. Milder temperatures are expected for Tuesday as well with highs in the mid-upper 40s over our northern sections and up near 50 along the KY/TN border.

Extended Forecast Discussion...

At the beginning of the extended forecast period, the teleconnection pattern is forecast to be in a -NAO/-AO/+EPO/+PNA/+WPO pattern. The MJO RMM plots show the MJO to be in the neutral circle. However, looking at global tropical satellite imagery, a large amount of convection was noted in the eastern Indian Ocean heading through SE Asia. This configuration is mainly a phase 6 pattern and forecast RMM plots do show the MJO moving out of the null circle and into phase 6 by mid-month. That overall configuration would favor a warmer pattern in the near term. The teleconnection forecasts do show the NAO/AO remaining negative through the period, with the EPO tanking after the 15th. This is probably a bit too fast given the MJO pattern by a couple of days. Looking at histograms of the EPO forecasts, the Euro has been delaying the EPO drop with each successive run. The WPO looks to trend negative so I think we may end up with a temperature pattern similar to December with coolness from the upper Plains into the Great Lakes and NE with the Ohio Valley seeing some ups/downs in temperatures. With the forecast MJO to rotate into phase 7 and eventually into phase 8 by late January and the EPO tanking negative (they are interconnected here), an overall colder pattern locally looks likely as we close out January and head into February. Climatologically speaking, the worst of our winter weather usually occurs between the MLK holiday and Valentine's Day.

Experimental signal analysis from late December suggested a few signal crossings of note. The first looks to be around 1/14-1/15 with a weaker signal around 1/17. These could be some clippers that rotate through the region. This could bring a period of wintry weather to the area. A stronger signal has emerged in the 1/19 through 1/22 period which could end up being two distinct passages which end up being some sort of east coast storms.

AVIATION /18Z TAFS THROUGH 00Z THURSDAY/

Issued at 1212 PM EST Tue Jan 6 2026

MVFR cigs will hold sway for the next few hours, but some clearing is working in from the west. So we should start to see cigs improve over at KHNB/KBWG later this afternoon. Clouds will stick around at KSDF for a little longer, probably clearing out a bit after 06/20Z, with KLEX seeing improvement after 06/22Z. Gusty southwest winds will be seen at the terminals this afternoon. Sustained winds of 8- 10kts with gusts to 22-24kts will be possible before winds subside towards sunset. The outlook for this evening and into the overnight hours calls for VFR conditions with generally light SW winds.

LMK WATCHES/WARNINGS/ADVISORIES

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