


Area Forecast Discussion
Issued by NWS Louisville, KY
Issued by NWS Louisville, KY
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782 FXUS63 KLMK 090143 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 943 PM EDT Tue Jul 8 2025 .KEY MESSAGES... * Isolated to scattered thunderstorms could produce locally gusty winds and brief torrential rainfall this afternoon. Storm coverage will diminish by this evening. * Warm and humid all week, with scattered showers and thunderstorms expected each day. Organized severe weather is not expected. && .UPDATE... Issued at 943 PM EDT Tue Jul 8 2025 Area radars are quiet at this hour as the nearest convection resides across southern TN and northern AL. A convective complex over the mid-Miss. valley has weakened over the past few hours, in line with this afternoon`s HRRR guidance. Would expect the rest of this area of showers and storms to fall apart with the loss of heating over the next few hours. For the rest of tonight into Wednesday morning, mostly dry conditions are expected. Baggy mid-level troughing is in place just NW of the area, and 10-15 kt low-level SW flow will persist across the southeastern half of the CWA. This may be just enough to set off a few showers early Wednesday morning; however, these should be fairly isolated. Convective debris clouds will drift overhead from the south and west overnight. While this may limit widespread fog development, patchy fog is still likely near bodies of water and in areas which received rain today. Otherwise, another seasonably mild night is expected, with lows falling into the upper 60s and lower 70s. For this update, just freshened overnight PoPs and temperatures to match latest hi-res trends. The forecast remains on track. && .SHORT TERM /THROUGH WEDNESDAY/... Issued at 319 PM EDT Tue Jul 8 2025 Weak sfc boundary is along the Ohio River today, with sfc temps in the upper 80s and low 90s across the forecast area, and dewpoints in the upper 60s and lower 70s. A cluster of thunderstorms is noted across western KY, being driven by a pocket of deep moisture convergence and upper level divergence. Despite marginal instability, little to no wind shear is keeping any convection unorganized. PWATs above 1.5" will support some heavy rain rates near the BWG area. Overall, this cluster of storms is expected to continue to weaken as it pushes east this afternoon. CAMs have performed poorly today, so confidence in additional precip outside of this cluster remains low. By this evening, the loss of daytime heating will promote a decease in precip activity. Overnight, mid-level clouds will linger overhead as we remain under the influence of general troughiness and the weak frontal boundary. Before sunrise, some patchy fog may develop, especially in our valleys and any areas that do pick up some rain this afternoon. For tomorrow, the weak boundary is expected to dissipate, though we will remain in a warm and muggy airmass. Stacked shortwave energy is supporting a sfc low over the Great Lakes, with a trailing cold front through the Midwest. This front will shift southeastward by tomorrow, and will be cutting across central IN and IL by the end of the day. The combination of warm daytime heating and muggy airmass, along with marginal instability ahead of the front, will support additional isolated to scattered shower and storm development across the region tomorrow, especially in the afternoon. Model soundings suggest PWATS to be above 1.7", suggesting heavy rain possible. Wind shear will be weak, leading to another day of messy garden variety storms, with slower storm motions. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... Issued at 319 PM EDT Tue Jul 8 2025 Upper level troughing will remain over the region for Wednesday night and into Thursday, with upper ridging centered over the southwestern US. A second weak cold front will be shifting southward through the upper Ohio Valley on Thursday, driven by a sfc low passing over the Great Lakes. Additional showers and storms will be possible Wednesday night and Thursday as we remain in a warm and humid airmass. The front is not expected to pass through the forecast area, likely getting stalled out north of the Ohio River on Thursday and Friday. This will keep our forecast area in the warm side of the boundary, with muggy dewpoints and above average PWATs available for afternoon destabilization as we warm into the upper 80s and lower 90s. Diurnally-driven storms will fire off in a marginally unstable environment, but weak flow in the column will keep wind shear weak. This will promote storms to be unorganized, though should be capable of producing heavy downpours and gusty winds. As we get into the weekend, the frontal boundary will lift north of the region, though additional shortwave energy will lead to another sfc low to track across the Great Lakes, and trail an associated cold front through the Midwest. We will remain warm and muggy, with highs both Saturday and Sunday in the upper 80s and lower 90s, and dewpoints in the lower 70s during peak heating. Shower and storm chances will continue each afternoon for the weekend and into early next week. Precip coverage is expected to diminish into the nighttime hours as we lose heating each day. && .AVIATION /00Z TAFS THROUGH 06Z THURSDAY/... Issued at 739 PM EDT Tue Jul 8 2025 Most of the shower and storm activity has pushed to the south and east of the region at this hour, and dry, VFR conditions are expected through the evening and early overnight hours. Mid- and upper-level cloud debris from convection to the west and southwest will move over the region later tonight, though this may not be enough to keep the typically foggy spots (i.e., HNB and BWG) from seeing visibility drops before dawn Wednesday. Winds should be light and variable overnight. For the day on Wednesday, predominantly VFR conditions are expected. Brief MVFR ceilings are possible depending on how much mixing occurs before the cu field develops. Otherwise, the main thing to look out for will be isolated TSRA during the afternoon and evening hours. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ UPDATE...CSG SHORT TERM...CJP LONG TERM...CJP AVIATION...CSG