textproduct: Louisville

KEY MESSAGES

* Chilly and dry today.

* Widespread rain and isolated to scattered storms expected Tuesday. A few stronger storms could produce small hail.

* Active weather pattern will bring multiples chances for rainfall Thursday through Saturday.

SHORT TERM /THROUGH TONIGHT/

Issued at 334 AM EST Mon Nov 17 2025

A cool, dry high pressure system remains over the Ohio Valley today. Winds will remain very light and somewhat variable, allowing temps to tumble into the upper 20s and lower 30s this morning under clear skies. Skies still look mostly sunny during the daytime, but we'll have a few more mid and high clouds drift in from the NW by the afternoon. Temperatures will rebound into the mid 50s to around 60 for highs.

Tonight, a compact low pressure system will rotate east from the central Plains over Iowa and Missouri. Increasing SW flow WAA and moist isentropic ascent will produce thickening mid-level clouds and rain showers across the Mid-MS and OH valleys. Light rain showers could spread into our SW Indiana and west-central KY counties around or shortly after midnight. Light to moderate rain showers will then overspread southern IN and the northern half of central KY through the predawn hours on Tuesday. Steepening mid-level lapse rates above the low-level warm nose will result in the development of weak elevated instability Tuesday morning. Thus, a few rumbles of thunder appear possible over the western half of the forecast area prior to 12Z/7 AM EST. The lower levels will remain quite cool and stable given the antecedent cool, dry airmass. Lows will range from the mid/upper 30s in the Bluegrass to the mid 40s along the Natcher Pkwy.

LONG TERM /TUESDAY THROUGH SUNDAY/

Issued at 334 AM EST Mon Nov 17 2025

Tuesday and Tuesday Night...

The mid/upper level shortwave trough over IA/MO initially will continue to swing east across the Midwest on Tuesday, with a 60 kt westerly mid-level jet expected to overspread the Lower OH Valley. This wave will provide increasing synoptic scale ascent, and a 40-45 kt SW low-level jet will produce strong low-level moisture transport across a warm frontal boundary. The warm front is forecast to lift slowly north through central KY as the weakening sfc low drifts ESE toward KY.

Numerous showers and isolated storms will likely be ongoing at 12Z Tue. Additional scattered convection appears likely through the afternoon and evening hours, with activity generally drifting ESE with time across central KY. Continued low-level WAA/moisture transport and the approaching mid-level wave will maximize elevated instability during the afternoon and evening hours. Forecast soundings and HREF data suggest MUCAPE of 500+ J/kg is possible south of the warm front. And with strong deep-layer shear in place, isolated strong storms are possible. Any stronger storm could produce small hail and brief heavy rainfall.

In addition, 00Z CAMs are hinting at possible scattered convection developing back closer to the sfc low/cold front near the Ohio River during the evening hours. The convective evolution is less certain by the evening, as any renewed development would be in the wake of afternoon showers/convection. At the very least, showers are likely to continue into the first half of Tuesday night as the sfc low/trough moves over the area. Rain chances diminish somewhat from NW to SE heading into Wednesday morning as the mid-level wave races east to the Mid-Atlantic coast.

Highs Tuesday will exhibit a large N-S gradient across the warm front. Expect temps to top out in the mid/upper 50s north of I-64, with upper 60s/near 70 in southern KY. This gradient will remain in place Tuesday night, with lows ranging from the mid 40s to mid 50s.

Wednesday - Thursday Night...

Broad upper level ridging develops east over the region for Wednesday, downstream of a deep upper low over Southern California. A quasi-stationary sfc boundary should linger in the vicinity, but Wednesday looks much drier overall due to dry mid-levels and a lack of any meaningful large scale lift. However, there is a signal for fog or low stratus Wednesday morning due to pooled moisture along the weak sfc boundary.

Additional rainfall does appear likely by Thursday and Thursday night due to mid-level energy emanating from the southwestern US trough. Rounds of lift/deep moisture transport will support additional waves of rainfall ahead of the southwestern US low ejecting northeast into the central Plains.

Friday - Sunday...

The low pressure system over the central Plains Thursday night should then get forced eastward across the Ohio Valley at the end of the week. It does appear we could get a cold front to pass through here by Saturday. Prior to the cold front's passage, additional widespread rainfall is likely with at least a small chance for thunderstorms. The second half of the weekend should trend drier with high pressure building in.

In terms of rainfall amounts, 0.5-1.0 inches appears possible Monday night through Wednesday morning in southern IN and much of central KY. Southern KY will likely see 0.25-0.50 inches. Higher rainfall amounts are likely Wednesday night through Saturday, though confidence in the details remains low.

AVIATION /06Z TAFS THROUGH 12Z TUESDAY/

Issued at 1234 AM EST Mon Nov 17 2025

VFR conditions likely. Mostly clear skies with light and variable winds expected today with high pressure in place. FEW-SCT mid and and high clouds will try to spread into the northern portion of the area late morning into the afternoon hours. A light SE wind will develop toward 03-06Z Tuesday ahead of the next weather system. Expect thickening clouds and lowering ceilings to 5-7 kft after 06Z Tue. Light rain showers are likely to move over HNB and SDF (and eventually LEX) between 06-12Z Tuesday.

LMK WATCHES/WARNINGS/ADVISORIES

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