textproduct: Louisville

KEY MESSAGES

* Isolated to scattered showers and thunderstorms are possible this afternoon and evening. A few stronger storms with gusty winds, torrential rainfall, and lightning are possible.

* Seasonable temperatures and daily chances for afternoon showers and thunderstorms are expected for most of the upcoming week.

UPDATE

Issued at 1051 AM EDT Sun Jul 5 2026

Observations this morning show clear to partly cloudy conditions across the region. Most concentrated cloud cover is over southern IN this morning. Temperatures have already warmed into the upper 70s and lower 80s across the region. Heading into the afternoon hours, we'll see temperatures climb into the mid-upper 80s. Convective temps are around 86-87 degrees, so once we surpass that, we should see scattered convection fire across the region. Model soundings show skinny CAPE profiles and low-mid level lapse rates are much less steep that what we've seen recently. PWATs are up there through, around 1.8-1.9 inches. Synoptic scale forcing is rather anemic again across the region. However a couple of MCVs will be worth a watch. One will be moving across portions of IN/OH which could clip our northern regions, the second will be a few in the southern stream which will bring convection to MS/AL/TN and perhaps into southern KY this evening. A few strong storms are possible with gusty winds, intense/frequent lightning and heavy rainfall. Most overall favored area for strong storms this afternoon will be well to our east across the Mid-Atlantic, but some strong storms will most likely be possible east of a line roughly from Bowling Green to Lexington.

SHORT TERM /THROUGH TONIGHT/

Issued at 341 AM EDT Sun Jul 5 2026

Over the past few hours, residual showers and thunderstorms have dissipated across the area, leaving us with scattered clouds and almost completely dry weather across central KY and southern IN. Temperatures have settled into the upper 60s and low-to-mid 70s as of 07Z, with areas that received rain Saturday evening slightly cooler than those which have not. Quiet conditions should continue this morning, with the main potential weather impact being development of patchy fog in areas with freshly saturated soils. Temperatures should remain steady in the upper 60s and low 70s through sunrise.

Over the past 24 hours, the upper ridge which has been over the southeast US for much of the past week began to break down, with baggy upper troughing now extending from the Ohio Valley into the upper Mississippi Valley. A weak area of sfc low pressure is currently located over the Ohio Valley, with a weakly-defined sfc front over the Great Lakes. Today, this upper trough and sfc front will track very slowly to the east-southeast, and the front should remain well north of our area through this evening. As a result, we'll still have a humid, but slightly less hot environment in place across the area, with highs expected to range between 86-90 this afternoon.

Speaking of moisture, PW values should be between the 80th and 90th percentile of climatology today (roughly 1.8-1.9"), though soundings suggest that more of this will come from richer mid- and upper-level moisture than moisture near the sfc. This may result in less thunderstorm fuel this afternoon and evening, as model skew-T plots show a much skinnier CAPE profile than in past days, with less steep low- and mid-level lapse rates. HREF median values of SBCAPE are between 1500-2500 J/kg across the area this afternoon, with higher values as you go toward the TN Valley. Nevertheless, this should still be sufficient for showers and storms to develop this afternoon and evening. As has been the case for the past few days, the key question is whether there will be sufficient forcing/triggering for more widespread storm development. 00Z short range model guidance suggests that several mid-level vort lobes/MCVs will be swinging around the edge of the upper trough this afternoon, with current progs splitting them to the south and north of the area. As a result, convective coverage may be limited initially, and may be dependent on other areas of showers and storms developing just outside of our area. Have reduced PoPs blended guidance, and expect isolated to maybe widely scattered coverage from mid-afternoon through early evening. While one or two strong storms will be possible, a less explosive thermodynamic profile may limit the wet microburst potential today, and only a small portion of the area from Lake Cumberland up into the southern Bluegrass region is in the Day 1 MRGL risk.

Would expect coverage of showers and storms to decrease once again by around midnight Monday morning, with a few showers potentially lingering into the pre-dawn hours. A fairly stagnant environment may lead to more fog development Monday morning, particularly in valleys and in areas which receive rain this afternoon. Lows should fall into the upper 60s and low 70s in most locations Monday morning.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 341 AM EDT Sun Jul 5 2026

The forecast over the first half of the week may be heavily influenced by the remnants of the upper low that will sink into the region later today. In contrast to earlier runs, the latest ensemble guidance tends to hold onto the upper low and associated sfc front for a considerable portion of the period Monday through Wednesday, also keeping a more moist air mass over the area. With weak vertical wind shear (~10 kt) and modest instability (1000-2000 J/kg) showing up in forecast soundings, it looks like a setup for garden-variety afternoon and evening showers and storms. Since the overall forcing is fairly modest, think that global models may be over-representing storm coverage, with isolated to scattered storms expected each afternoon Monday and Tuesday. There may be enough of an eastward push in the low by Wednesday for diminished storm coverage across our area, though confidence in this is fairly low at this time. Seasonable temperatures are expected for Monday through Wednesday night, with highs ranging from 85-90 and lows in the upper 60s and low 70s.

By Thursday, another low-amplitude upper trough is expected to slide across the north and northeast side of upper ridging over the Rockies and Plains, bringing a sfc cold front toward the Ohio Valley for the end of the week into next weekend. Ensemble guidance shows a resurgence of moisture ahead of this next system, with PW values rising to around 1.7-1.9". Increasing moisture should likewise increase instability, and somewhat stronger mid- and upper-level winds should support stronger shear and more storm organization. Like this trough this weekend, the late week system may struggle to gain amplitude, causing the sfc front to slowly push through the area or even stall by early next weekend. As a result, another unsettled period of weather looks increasingly likely Friday into next weekend, with daily chances for scattered to numerous showers and storms. Temperatures may warm a bit Thursday ahead of the approaching front, but then fairly seasonable temperatures are likely for Friday into next weekend.

AVIATION /12Z TAFS THROUGH 18Z MONDAY/

Issued at 708 AM EDT Sun Jul 5 2026

This morning, VFR conditions should resume at all sites once low- level moisture scatters out from HNB in the next few hours. Can't rule out a brief MVFR/IFR cloud deck trying to form at SDF, but this should scatter out fairly quickly if it develops. Light W/SW winds are expected today, with speeds generally between 5-10 kt from late morning through the afternoon. Isolated SHRA/TSRA will be possible at all sites this afternoon and evening (main window 20Z-02Z), but we'll leave it out of the forecast for now at all sites but HNB due to limited coverage.

Tonight, light and variable winds are expected, with a weak cold front trying to push into the region from the north. Low-level moisture may settle into patchy fog and/or low clouds from north to south after 06Z tonight, but confidence is low at this lead time.

LMK WATCHES/WARNINGS/ADVISORIES

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