FXUS63 KLMK 200716 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 316 AM EDT Wed May 20 2026 .KEY MESSAGES... * Periods of showers and storms will move across southern Indiana and portions of north-central Kentucky this morning. Heavy rainfall will be possible with localized flooding across southern Indiana. * Another round of showers and storms is expected this afternoon. A marginal risk of strong/severe storms exists across the east- central and eastern Kentucky with damaging winds being the main threat. * Busy weather pattern will ramp back up late Thursday and through the holiday weekend with episodic bouts of showers/storms with heavy, but welcome rainfall. && .SHORT TERM /THROUGH THURSDAY NIGHT/... Issued at 316 AM EDT Wed May 20 2026 Broad southwest flow continues aloft across the region this morning. A small perturbation moving northeast within this flow has helped kick off a persistent band of showers/storms from western Kentucky into southwestern Indiana. This corridor of convection is rooted within the low-level jet axis and also resides in a PWAT plume extending from west TN northeastward into southern Indiana. Within this corridor PWAT values are running in the 1.5-1.9 inch range. This convection will move off to the northeast through the remainder of the overnight hours and move across southern Indiana where recent rainfall has fallen in the last 24-36 hours. The convection has generated some cool outflow which is surging eastward toward the I- 65 corridor. PWAT values do decrease markedly east of the I-65 corridor. Given that we have some elevated instability in the I-65 corridor and points west, expect this outflow to generate some additional shower/storms from Hartford northeast through the Louisville metro over the next few hours. Shear remains very marginal here, so severe weather is not anticipated. However, a swath of moderate to occasionally heavy rainfall will move across saturated soils over southern Indiana and may produce some local hydro issues this morning. Current flood watch over southern Indiana continues to look good and no headline changes will be made with this forecast. Moving into the daytime hours, surface cold front off to our west this morning will move into the region this morning and into the afternoon hours. As this occurs, another small perturbation aloft will move northeast across the region and produce another round of convection across the region. As the cold front heads eastward through Kentucky, some diurnal heating will be noted across the central and eastern portions of the forecast area. MLCAPE is forecast to rise into the 800-1300 J/kg range this afternoon. Model soundings show rather poor mid-level lapse rates, but the low-level lapse rates are pretty steep. That, along with convergence along the front should allow widespread showers with some embedded thunderstorms to track across the region. Some of the storms could be strong this afternoon, mainly east of the I-65 corridor. Main threats will be heavy rainfall and gusty thunderstorm winds. Highs today will feature a gradient with readings only reaching the low- mid 70s across the west, with upper 70s to lower 80s out in the I-75 corridor. Surface cold front is expected to continue eastward this evening with showers ending from northwest to the southeast into the late overnight period. Cool northerly flow will usher in some cooler air into the region. Lows tonight will drop into the mid-upper 50s across southern Indiana with lower 60s across southern Kentucky. For Thursday, we'll see a brief pause in the wet weather as the front stalls out to our south. Blended PoPs keep some chances of showers down across southern KY, but this looks a bit too aggressive and I expect those PoPs to decrease over the next few runs. Highs on Thursday will be a little cooler than normal with readings only reaching the lower 70s over southern Indiana and the northern half of Kentucky. Mid-upper 70s will be found over the southern part of Kentucky. The stalled out front will start to return northward late Thursday night as a warm front. Ahead of that warm front, another round of showers is likely to develop in advance of that feature. Lows will range from the upper 50s over southern Indiana and northern Kentucky to the lower 60s over southern Kentucky. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Issued at 316 AM EDT Wed May 20 2026 For the extended portion of the forecast period, unsettled weather looks likely for Friday and through the Memorial Day weekend as broad southwest flow will remain in place across the region. Several weak perturbations aloft will move through the region bringing episodic bouts/rounds of showers and storms to the region. Now, this doesn't appear to be a total washout in all places. However, several rounds of showers/storms will be moving across the region and will bring heavy rainfall, lightning, and gusty winds at times. The upper level pattern will flatten out a bit by Monday with a possible split flow pattern developing as we may get a cut off low to develop over portions of Texas. Confluent flow east of the cutoff low across the Ohio Valley will allow a frontal boundary to remain nearly stationary across the region and this feature will be a focus of renewed convective development through the end of the forecast period. Moisture transport into the region will be high and PWATs will be running well above climatology here. So periods of heavy rainfall are expected. This rainfall will be welcome to much of Kentucky that has seen a rather dry period of weather of late. QPF amounts of 2-4 inches will be possible across the region with locally higher amounts in areas that see training. While much of this rainfall could see good infiltration into the ground, we could end up seeing some hydro problems develop in areas that have seen recent rainfall. Highs on Friday will generally be in the upper 70s to the lower 80s. Temperatures for Saturday through Tuesday will see daytime highs mainly in the lower 80s with overnight lows in the 60s. Looking past the 7 day period, longer range guidance suggests that we could see some high latitude blocking redevelop over Canada which will result in a fairly amplified flow pattern across the CONUS. There is a pretty decent signal in the data suggesting above normal rainfall closing out May and heading into early June, though temperatures look to remain seasonal through this time frame. && .AVIATION /06Z TAFS THROUGH 12Z THURSDAY/... Issued at 110 AM EDT Wed May 20 2026 For the remainder of the overnight period, conditions will start off as VFR at the terminals with ceilings gradually lowering toward dawn. Scattered convection will be possible, mainly west of a line from BWG to HNB. Surface cold front will push through the region after dawn which will allow winds to shift to the northwest. As we move into the late morning hours, an upper level perturbation will move northeast along the sagging front which will kick off additional showers/storms, mainly east of a line from BWG to LEX. Cigs will likely drop into the IFR range with MVFR vsbys due to rain/storms. Convective activity will push off to the east toward the end of the period with IFR cigs remaining in place. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...Flood Watch until 2 PM EDT this afternoon for KYZ032. IN...Flood Watch until 2 PM EDT /1 PM CDT/ this afternoon for INZ076>079-083-084-089>092. && $$ SHORT TERM...MJ LONG TERM....MJ AVIATION.....MJ