textproduct: Louisville

KEY MESSAGES

* Dry weather combines with pleasant temperatures and humidity through late week.

* Shower and storm chances return heading into the weekend, and heat and humidity return late weekend into early next week. Max afternoon heat indices could be in the triple digits for some by early next week.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 253 AM EDT Thu Jul 23 2026

Another nice day expected across the region as high pressure sits over the Great Lakes region, and extends influence through the Tennessee Valley. There is a frontal boundary parked down along the northern Gulf Coast states, but it will be no factor through the late week time frame. We'll see steady NE surface winds today, and despite mostly sunny skies temperatures are only expected to reach the upper 70s and low 80s. These below normal temps combined with dew points in the 50s for most of the area will bring a pleasant feel for late July.

After another cool overnight tonight with lows in the upper 50s and low 60s, look for highs on Friday to rebound a bit more into the low 80s. This is still notably below normal for this time of year and dew points will remain more comfortable in the 55 to 60 degree range for most. Dry conditions remain through Friday.

We will have to reintroduce some shower and storm chances across the southern half of the CWA by Friday night as the aforementioned frontal boundary lifts north as a weak warm front, and could be the trigger for some scattered coverage heading into early Saturday.

LONG TERM /SATURDAY THROUGH WEDNESDAY/

Issued at 253 AM EDT Thu Jul 23 2026

This Weekend...

Strong upper ridging is expected to build from the western CONUS into the central US through the weekend, with the eastern extent of the upper ridge edging toward the mid Mississippi River Valley. Meanwhile, troughing is expected to persist across the eastern Great Lakes into New England. Our region will be situated in the persistent NW flow between these two upper features, while surface high pressure from the late week time frame loses influence over the area. This will allow for a re-introduction of shower and storm chances through the weekend as the stalled frontal boundary to our south lifts back to the north near our southern CWA as a weak warm front. In addition, could get some weak shortwave perturbations moving through the NW flow aloft. Tough to nail down any particular timing as differences in individual waves vary among the different model suites, however most likely times would be Saturday and Sunday afternoon and evenings given diurnal trends. Overall, the low level shear profile does not look favorable for organized updrafts on Saturday, however there could be some decent flow above 500 mb. Will mainly be looking for isolated to scattered pulse storm modes here. Sunday could bring more deep layer shear (especially above 500 mb), in the presence of strong instability (ML CAPE values over 3000 J/KG), however low level lapse rates are quite crappy, and LFC values will be quite high. Not sure if there will be enough of a trigger to initiate convection. If so, we could get some organized severe, but confidence is low and data is sporadic on any meaningful convective initiation or not.

Outside of the shower and storm chances, we'll also see increasing heat and humidity by late weekend as the upper ridge starts to build closer to the area. Expecting highs back in the upper 80s to around 90 by Sunday, with dew points creeping back into the upper 60s and low 70s. This could yield max heat indices back in the 95 to 100 degree range along and west of I-65 for Sunday.

Monday - Wednesday...

The pattern is pretty interesting for the early week time frame as we remain situated in the NW flow aloft between west/central CONUS ridging and eastern CONUS troughing. This setup will allow for a strongly unstable airmass on the eastern periphery of the upper ridge, along with sufficient deep layer shear in that NW flow pattern, especially with any embedded shortwave activity. This is a classic setup for forward propagating MCS activity assuming there isn't too much capping, and that shortwave placement is relatively reliable at this range. For the moment, there is plenty of data to support the stronger/more widespread activity tracks just to our north and east, but given where the instability gradient will be combined with enough deep layer shear we could be in the game for at least 1 or perhaps multiple rounds of MCS activity Monday and Tuesday. Confidence isn't overly high on any one time period early week, but the overall pattern suggests MCS activity will occur somewhere in the region. Right now, our NE CWA is most susceptible.

In addition to the strong storm chances, we'll also have to keep an eye on the building heat and humidity. Right now, Monday afternoon looks to be the most oppressive with high temperatures climbing to the low 90s combined with dew points in the low and mid 70s. Could see some max heat indices jumping into the 100 to 105 degree range along and west of I-65. This heat threat could be muted by any of the aforementioned MCS activity should it occur. Or, it could be worse than currently advertised if no MCS activity impacts our area. Stay tuned there.

The same overall pattern could persist into the middle of next week, however it does look like temps/humidity will lessen by Wednesday in the wake of a cold front and/or convectively reinforced cold pool. Will keep some isolated shower/storm chances in here, but overall may have a brief reprieve from the worst heat/humidity and storm chances mid week.

AVIATION /12Z TAFS THROUGH 18Z FRIDAY/

Issued at 623 AM EDT Thu Jul 23 2026

High pressure keeps the region VFR through this TAF cycle. One caveat is some brief MVFR/VFR threshold BR at HNB early this morning. Other than a few cu around 4-5 k feet from late morning through the afternoon, look for mostly sunny/clear skies. Look for a light to steady NE surface wind.

LMK WATCHES/WARNINGS/ADVISORIES

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