textproduct: Louisville

KEY MESSAGES

* Hot and humid conditions are expected this afternoon and again on Thursday. Peak afternoon heat indices of 95-105 are possible each afternoon.

* An approaching cold front Thursday Night/Friday will provide another opportunity for showers and storms, timing remains a bit uncertain.

* After a dry Saturday, an unsettled and overall cooler pattern takes hold for late weekend into early next week.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 250 PM EDT Wed Jun 10 2026

Short term ridging has built into the region today and resulted in a much drier pattern across the region. Satellite and observations reveal mostly sunny skies across southern Indiana and central Kentucky. Abundant low-level moisture remains in place and has led to a fairly dense Cu field. Despite the Cu field, temperatures have warmed into the the mid-upper 80s. A few of the urban centers have already breached 90. These temps combined with dewpoints in the low- mid 70s has resulted in heat indices in the mid-upper 90s with a few spots out in the I-165 corridor breaking 100 degrees.

For the remainder of the afternoon, no significant weather is expected. Afternoon highs will top out in the 85-90 degrees with heat index readings topping out in the mid-upper 90s. The best chances of seeing heat indices above 100 will be limited to areas along and west of I-65.

For tonight, ridging will stay in place aloft resulting in a quiet/tranquil weather period. Overnight lows look to drop into the lower 70s for most area. The urban corridors will likely remain milder with readings in the middle 70s. Will need to watch upstream convection over the Midwest. Most model guidance shows this convection weakening overnight as it approaches the region, though a few model outliers believe that some shower/storms could get into southern Indiana. We'll continue to monitor this, and a forecast update later this evening may have to add some low PoPs for the northern portions of southern IN if convection does indeed hold together.

Moving into Thursday, ridging will hold sway across the region with mostly sunny skies and hot/humid conditions continuing. We'll see some instability develop across our northern tier of counties across southern Indiana, but there is not particularly strong forcing present to develop convection. Additionally model proximity soundings show a warm layer up around 700 mb that will effective be a cap that might be too strong for any weak forcing to overcome. Highs tomorrow may be a smidge higher than today with readings again in the upper 80s to the very low 90s. Combine those temps with dewpoints in the mid-upper 70s will yield another day of afternoon heat indices in the upper 90s to the lower 100s. Confidence is not that high that we'll breach 105 for heat advisory criteria, even out in the I-165 corridor. So we're planning on carrying on with the Special Weather Statement to highlight the early season heat/humidity.

By Thursday night, we'll refocus our attention to another round of convection that should be in progress across the Midwest region of the US. Most model guidance suggests that a linear MCS will develop and eventually generate a deep cold pool allowing the convection to surge southeast. This activity will enter our region during the diurnal minimum and we'll have an environment that will be increasingly hostile for convection. I do have enough confidence to warrant higher PoPs across southern IN with lesser chances along/south of the Ohio River. Overall, I like the Marginal Risk for our northern areas from SPC for tomorrow night for a possible wind threat with the decaying convection. Lows will drop into the upper 60s over southern IN with lower 70s across all of central Kentucky.

LONG TERM /FRIDAY THROUGH TUESDAY/

Issued at 250 PM EDT Wed Jun 10 2026

Friday through Friday Night...

On Friday we'll see the remnants of the aforementioned MCS passing southward through our region. Just behind this system, a surface cold front will push through the region and bring some relief from the heat/humidity. As the front pushes southeast across the region, we could see some convective redevelopment across our eastern/southeastern sections and some of those storms could be strong/severe. This activity looks to push off to the southeast by evening with a drier stretch of weather expected by Friday night.

Highs on Friday will be a little cooler with highs in the mid-upper 80s, but the main story here will be surge of much lower dewpoints into the region which will remove the mugginess that we've seen recently. Lows Friday night will drop into the upper 50s and lower 60s.

Saturday through Sunday Night...

Forecast confidence continues to increase here with a dry period of weather for Saturday. The flow aloft across the region will be zonal with a weak surface high pressure cell moving across the region. Highs on Saturday will warm into the 83-88 degree range. Surface cold front from Friday will stall out to our south due to it becoming parallel with the upper level flow. This boundary will remain quasi-stationary across the region Saturday night and into Sunday. Within this same time frame, an upper level trough axis will approach from the northwest Saturday night and result in an uptick of showers/storms across the region that will persist into Sunday. Highs on Sunday will likely be limited due to anticipated clouds/convection, so will go with highs in the low-mid 80s here. Lows Sunday night will be in the mid 60s.

Monday through Thursday...

Overall forecast confidence in the period remains slightly below average as questions remain if we can get the upper level flow to become less zonal and push our quasi-stationary boundary southward. Am setting a little bit of a drier push on Monday in the Euro guidance, but still think that low end PoPs will be needed in that time period. For Tuesday and beyond, we'll remain in the cyclonic flow of the upper trough and numerous small perturbations will rotate through. The overall ensemble blend here has trended slightly drier, but at least climo PoPs are likely to be maintained here until forecast confidence increases. Temperatures will remain a bit below normal with low-mid 80s for highs and overnight lows in the lower 60s.

AVIATION /18Z TAFS THROUGH 00Z FRIDAY/

Issued at 118 PM EDT Wed Jun 10 2026

VFR conditions are expected through this TAF period as high pressure holds sway across the region. We'll see a steady southwest flow this afternoon with sustained winds of 10-13kts and occasional gusts to 18-19kt, but these winds will diminish toward sunset. Ample moisture in the column will lead to a sct-bkn deck around 3500-4000 ft agl this afternoon. That Cu field will diminish toward sunset with VFR conditions expected overnight and into the day on Thursday.

LMK WATCHES/WARNINGS/ADVISORIES

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