textproduct: Louisville

KEY MESSAGES

* A main line of showers and storms arrives by late morning, bringing heavy downpours, lightning and the risk for isolated flash flooding and severe wind gusts. * Communities further south and east of the Bluegrass Parkway have the best chance of near record highs in the upper 80s to low 90s. Further NW, storms arrive sooner, limiting heating potential.

* Warmth remains after a foggy Thursday morning, with a strong cold front moving in Friday. This front will increase frost potential Saturday night into Sunday.

DISCUSSION

Issued at 330 AM EDT Wed Oct 14 2026

===== Anticipating Isolated Flash Flooding Threat Today and Warm=====

Now in the early overnight, the CWA is going through another quiet period well ahead of a trough that has dug itself deep over the southern Plains into the Texas panhandle. With the aid of strong moisture transport at the surface and all the way up to 700mb, there is plenty of juice for potential showers and storms to rely on to produce heavy downpours.

Currently, storms have fired off near central Missouri and seem to be on track to arrive in our CWA by late morning to the early afternoon hours hitting our southern Indiana counties first in a SW- NE oriented line. PWATs will be increasing ahead of the storms reaching near or just over 2.00" which is at all but the 100th percentile of climatology. Instability will increase ahead of the line of storms with modeled MUCAPE reaching near 1,500 J/kg in some areas by this afternoon. However, the best shear will remain too far north of our area, along with less than favorable jet dynamics to further support lift as these storm progress eastwards towards central and later eastern KY. That being said, these storms should be fairly progressive despite the amount of juice in the atmosphere. Additionally, at this time, it appears should there be another wave of storms late this evening that the primary wave should produce more rain than any subsequent wave. All this to say it appears the flash flood threat will be mostly limited to this first round of rain and it remains to be seen how much additional rain will fall beyond that.

Looking upstream, personal weather stations have been reporting at most 2-3". Even here, there is better forcing for lift without at least widespread reports of over 4" or so. Knowing this, rainfall totals should vary from location to location, with 25th-75th percentile total precipitation estimates from HREF data ranging about 0.25-1". Short range models are struggling to ascertain how the somewhat limited instability and storms diverging from the best support will evolve over KY, hence the rather large spread in rainfall totals (HREF values of total precipitation is currently left skewed to under 0.5").

These storms out in Missouri are tending to grow in vertical height, collapse under their own weight, and gust out a surface boundary that chokes out the next line of storms too far into the cold pool while acting as an axis of convective activity for cells further south rising into and above the boundary. There's currently a boundary situated west-to-east just south of St. Louis that may focus the next incoming round of storms. Should the next round now in central Missouri hold together without collapsing first, it would affect most of our CWA by late morning/early afternoon. 6hr LPMM data from HREF indicate isolated areas of 2-5" are possible by Wednesday evening after that first line passes through. The biggest concern for any flash flooding according to the latest 6hr FFG would be southern Indiana counties, a south-north oriented stripe of communities from Hart to Trimble counties (from rainfall from Isaias), and the Bluegrass region NE of Lexington. Strong to severe gusty winds are possible with these storms as well, should they continue to build up and collapse, though the larger concern remains isolated flash flooding.

Highs today range in the upper 70s across southern Indiana (who will be the first to cloud over from convective debris and incoming storms) to the mid and upper 80s near Lake Cumberland. High forecasts are tricky today and will solely depend on the speed and prevalence of storms. A strong high temperature gradient may exist between NW and SE areas as a result.

The boundary responsible for the storms today will stall somewhere over our area by evening, most likely close to the TN. Communities north of this line will remain on the cool side versus warm and continuous SW flow south of this line. Moisture will stay locked in overnight, and with calming winds and remnant chances of showers riding along the boundary from west to east, widespread fog is likely to form at least north of the boundary.

=====Lingering Showers and Warm Thursday=====

Beginning Thursday morning, another developing low will move across the central Plains near Iowa and move towards Great Lakes region, helping to strengthen a return to SW flow in the afternoon. This in turn will lift our aforementioned boundary as a warm front through the Ohio Valley and a return to summery heat --again, this late in October! The center of the low and continuous moist flow from the Gulf may be close enough to spawn additional showers in the morning as the warm front passes through, but otherwise by mid afternoon, we begin to dry with highs in the upper 80s across the south to low 80s and upper 70s across the north. It should be noted that should rain keep falling, it's more likely to fall in the north while the south stays warm and drier.

=====Plummeting Temperatures and Growing Frost Potential=====

Lastly, the low over the Great Lakes by this point will strengthen and shove a strong cold front through the Ohio Valley near early to mid-morning Friday. We'll know when it will have passed from the presence of a line of showers with it, increased diurnal wind gusts up to 30 MPH, and plummeting temperatures during the day. Should communities closest to the SE see the low to mid 70s for highs, the front will quickly drop temperatures into the mid 60s before sunset with lows overnight Friday into Saturday reaching the upper 30s to low 40s.

In the wake of the passing cold front, a high pressure will build in, keeping calm weather in place along with a cooler air mass. Highs will struggle to even reach the 60s Saturday afternoon. Lows Saturday will fall into the low to upper 30s, meaning the potential for frost is growing, especially across southern Indiana and the Bluegrass region. Cooler air remains Sunday but the high pressure overhead will begin to shift eastwards. This means that by Monday, long range trends indicate southerly flow returns with upper 60s and mid 70s by at least Tuesday, remaining dry as well.

AVIATION /12Z TAFS THROUGH 18Z THURSDAY/

Issued at 708 AM EDT Wed Oct 14 2026

VFR conditions will continue through the morning albeit with passing cloud decks that may become SCT-BKN at mid levels along with high level cirrus clouds. SW flow will strengthen today ahead of a main line of showers and storms that will move in from the west, affecting HNB-SDF-BWG first. These have the potential for brief reduced visibilities and gusts up to 25kts or more. Throughout the day, clouds will thicken and lower. Winds will shift behind the line of storms from north to south shifting out of the N and NW by the evening hours. Besides lingering showers overnight, lowering MVFR ceilings are expected as a front stalls over KY. BWG may remain high- end MVFR to low end VFR overnight as showers wind down with possible drizzle north of BWG. MVFR-IFR conditions expected by Thursday morning.

LMK WATCHES/WARNINGS/ADVISORIES

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