737 FXUS63 KLMK 050752 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 352 AM EDT Thu Jun 5 2025 .KEY MESSAGES... * Strong to severe storms possible today through Saturday, with Friday holding the greatest potential. * Excessive rainfall is possible as a surface boundary stalls across the region. 1 to 2 inches of rainfall could occur late this week and into the weekend resulting in localized flooding. && .SHORT TERM /THROUGH TONIGHT/... Issued at 352 AM EDT Thu Jun 5 2025 This morning, an upper trough dives south along the Pacific Coast then shoots to the northeast, over the CONUS. This includes the Lower Ohio Valley. At the surface, a very weak southwest to northeast oriented surface front sits northeast of the CWA as it stretches across southern Illinois and central Indiana. North of the front, surface high pressure sits over the Midwest, and east of the front, along the Atlantic Coast, another area of high pressure sits. Along the front low pressure will help funnel Gulf moisture north before flowing along the front. Precipitable water values along the front will range between 1.5-2" today. Currently, overnight convection continues to slide east over southern Indiana and western Kentucky. As it does this, it`s been slowly weakening. Lightning counts continue to fall, but after diurnal warming begins and temperatures lift back into the 80s, scattered thunderstorms area expected to increase and last into the night. Believe the best chances for precipitation will remain closer to the front with lower chances to the southeast, towards the Lake Cumberland area. Deep layer shear remains weak, so organized storms will be less likely. Lightning is likely the greatest threat with gusty sub-severe winds and hail possible. The high moisture levels and weak shear will likely cause any hail to experience melting before reaching the ground, limiting its size. Tonight, showers and thunderstorms are expected to expand farther to the east with an overall decrease in activity. Under broken skies and light winds, temperatures are expected to fall into the mid 60s to low 70s. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Issued at 352 AM EDT Thu Jun 5 2025 By Friday, there will be only slight changes in the overall pattern as upper flow becomes more zonal over the Lower Ohio Valley. This will push the surface, low near the front, east towards Ohio. This will cause the nearly stationary front to drop south to near the Ohio River and become more west-southwest to east-northeast oriented. During the morning hours, isolated convection could remain in the area, but the main area of focus on Friday comes from an expected MCS that is expected to develop over the southern Plains, travel through the Ozarks, and continue into the Tennessee and Lower Ohio Valleys. Shear remains unidirectional and weak, but the driving force with this system will be the instability from diurnal warming. Current model runs has this system arriving during peak heating during the afternoon and evening hours. MLCAPE values could reach to around 1,500 J/kg before the system arrives. Some hail is possible, but the main threat will be gusty winds as the system moves through the region. Through the weekend, a shortwave and upper low work over the CWA. In the moist environment, periods of showers and thunderstorms will remain possible. Overall fairly light rainfall totals aren`t expected to cause any flooding issues. Temperatures remain consistent with highs in the upper 70s to low 80s and lows in the 60s to low 70s. By around Tuesday, a cold front is expected to drop south through the region and bring a period of drier weather. && .AVIATION /06Z TAFS THROUGH 12Z FRIDAY/... Issued at 150 AM EDT Thu Jun 5 2025 The slow moving northeast to southwest oriented front is expected to remain northwest of southern Indiana and central Kentucky through the period, but ahead of the front, a line of precipitation is slowly working east towards area TAF sites. This line will first impact HNB within the next hour or so. A decent amount of lightning remains in the line, but the line is expected to weaken as it moves to the east overnight. MVFR ceilings are expected at HNB and could make it as far east as SDF before lifting. The chance remain low that MVFR ceilings make it to SDF before diurnal warming lifts ceiling, so VFR ceilings were left in the SDF TAF. This afternoon after some warming, more scattered thunderstorm activity is expected to develop and work east over the TAF sites. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ SHORT TERM...KDW LONG TERM...KDW AVIATION...KDW