textproduct: Louisville

KEY MESSAGES

* Breezy and warm conditions are expected on Wednesday. Wind gusts of 20 to 30 mph, with sporadic gusts up to 35 mph, are expected.

* The next chance of rain will come Friday as a cold front brings showers and possibly a few strong thunderstorms to the area.

* Another cold front late this weekend could bring highs in the 40s early next week.

UPDATE

Issued at 957 PM EST Tue Nov 4 2025

Evening satellite imagery shows mostly clear skies across the region with just some high clouds moving across the area. Temperatures were in the lower 40s out in the rural areas and more protected/sheltered regions. On the ridges and in the urban areas, temps were still in the mid 50s.

For the overnight hours, light southeast winds are expected to shift more to the south and eventually the southwest by late tonight. Temps will not fall off all that much due to the increased winds within the boundary layer.

SHORT TERM /THROUGH WEDNESDAY NIGHT/

Issued at 355 PM EST Tue Nov 4 2025

This afternoon, sfc high pressure is centered over the southern Appalachians with low pressure developing over the northern Plains. The upper-level pattern is fairly zonal across North America, but is expected to amplify tonight into tomorrow as a couple upper-level and sfc disturbance moves across the northern US. While the sfc low is expected to traverse the upper Great Lakes, a trailing cold front will approach and cross the Ohio Valley tomorrow.

Tonight, as the sfc pressure gradient tightens due to falling pressures to the north and west of the area, light south winds should continue overnight, on the order of 5 to 10 mph. As a result of more well-mixed conditions tonight, temperatures will be noticeably milder overnight with fog development being unlikely, even in the typically foggy areas. Lows are expected to fall to around 50 degrees in the warmer urban centers, with cooler valleys (especially across east-central and southeast KY) expected to fall into the low-to-mid 40s.

Tomorrow should be a warm and breezy day across the area, with temperatures warming into the upper 60s and low 70s across southern IN and central KY. While there will be tepid moisture advection ahead of the front, PW values are only expected to increase to around 0.75" immediately ahead of the front, and soundings suggest that this will manifest as scattered mid- and upper-level clouds. What will be more noteworthy tomorrow will be the stronger SW wind gusts, with BUFKIT momentum transfer progs showing the potential for a few 25+ kt gusts, especially along and north of I-64 tomorrow afternoon. On average, sustained winds of 10 to 20 mph looks like a pretty good bet, with wind gusts generally around 20 to 30 mph, with sporadic 30+ mph gusts.

Winds will continue to veer Wednesday afternoon into Wednesday night as the cold front finally sweeps through the region. This should allow for modest cold advection to begin, with winds slacking Wednesday night as high pressure begins to move into the area once again. Under mostly clear skies, temperatures should fall into the mid-to-upper 30s and low 40s Thursday morning.

LONG TERM /THURSDAY THROUGH TUESDAY/

Issued at 355 PM EST Tue Nov 4 2025

Thursday - Thursday Night...

The extended forecast period should start out with dry weather and seasonable temperatures on Thursday as high pressure starts the day over the Ohio Valley. The upper-level pattern will remain fairly zonal through the day on Thursday, with low amplitude ridging moving across the Mississippi and Ohio Valleys. While weak warm advection should begin Thursday evening into Thursday night, high temperatures should be cooler than tomorrow, ranging from the upper 50s across the northeast CWA to the mid 60s along the TN border.

Thursday night, an upper-level shortwave will begin to amplify over the north central US, sinking across the Midwest as we head into Friday morning. Low-level response to falling heights aloft will lead to a strengthening southwesterly LLJ, increasing moisture and bringing warmer air into the region. At this time, Thursday night into early Friday morning is expected to remain dry, though clouds should increase from NW to SE. Low temperatures will be considerably milder Thursday night, with most locations falling into the 40s.

Friday - Friday Night...

The main system of interest in the long term arrives during the day on Friday as a cold front associated with the aforementioned shortwave pushes from west to east across the region. Moisture advection Thursday night into Friday morning should result in a plume of sfc dewpoints in the upper 50s and lower 60s and PWATs of 1.1-1.3" just ahead of the cold front. The combination of moisture and forcing from the cold front should lead to a band of rain showers developing in the vicinity of the front during the day on Friday. There continues to be some timing differences between the ECMWF, which has precipitation moving through the area earlier in the day, and the GFS, which has precipitation moving through later in the afternoon and evening on Friday.

As previous discussion and the SPC extended outlook have noted, there is a low, but non-zero chance for a few gusty thunderstorms on Friday, some of which could be strong to severe. Instability will be meager, on the order of 300-500 J/kg, and sounding profiles suggest that instability will be spread throughout a relatively deep layer (a.k.a. a "tall, skinny CAPE" profile). On the other hand, strong flow aloft will support seasonably strong deep layer shear, on the order of 50 kt. While the low-level wind profiles are fairly veered/unidirectional, there is enough curvature in the hodograph to feature a conditional low tornado threat, in addition to strong straight-line winds. In short, severe weather still looks unlikely on Friday, but a conditional threat exists if sufficient sfc-based instability is realized.

Outside of the storm potential, gusty gradient winds are likely during the day on Friday. While uncertainties surrounding cloud cover and low-level lapse rates abound, it is likely that widespread wind gusts of 25 to 35 mph will be observed, with peak gusts of 35 to 45 mph possible.

The main line of precipitation associated with the cold front should clear to the east of the region by Friday night, with winds gradually dissipating by Saturday morning.

Saturday - Monday Night...

For the weekend into early next week, longwave troughing will settle across the eastern CONUS as ridging builds along the west coast. Within the base of the broader upper trough, several shortwaves will pivot across the region, leading to a somewhat unsettled pattern.

After a mostly dry day on Saturday, medium-range guidance has converged on a disturbance swinging across the region Saturday night into Sunday morning. While precipitation amounts are expected to be light, this system will bring a reinforcing shot of cold air for the end of the weekend into early next week. Strong cold advection Sunday into Sunday night will cause temperatures to struggle to warm into the upper 40s and 50s on Sunday before falling into the 30s (possibly upper 20s) Sunday night. At this point, there is considerable disagreement surrounding an additional wave which could bring a chance for rain, and possibly mixed rain and snow showers, Sunday night into Monday morning. The GFS and its ensembles is farther to the east with this disturbance, keeping the best chance of precipitation over the Appalachians. On the other hand, the deterministic ECMWF and associated ensembles brings these wintry showers across our area. Since precipitation amounts should be light and temperatures will be marginal, this event, if it is borne out, doesn't look all that impactful, but is something worth watching.

Once the trough reaches its peak amplitude next Monday, temperatures should gradually begin to moderate as we head into the middle of next week. The coldest air so far this year should keep highs in the low 40s on Monday, with widespread lows in the 20s possible Monday night. Drier weather is expected by Monday afternoon, continuing into next Tuesday.

AVIATION /00Z TAFS THROUGH 06Z THURSDAY/

Issued at 614 PM EST Tue Nov 4 2025

VFR conditions are expected during the upcoming TAF period. Main concern overnight will be an approaching from the northwest. A LLJ will spread over the region resulting in in LLWS after 05/06Z and continuing into mid-morning Wednesday.

Winds will gradually increase and veer to the SSW late tonight. Winds will become gusty late tomorrow morning, with 20-30 kt gusts expected by the end of the current forecast period.

LMK WATCHES/WARNINGS/ADVISORIES

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