766 FXUS63 KLMK 111443 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 1043 AM EDT Thu Jul 11 2024 .KEY MESSAGES... * Mostly dry weather and warming temperatures expected for Friday through early next week. Worsening drought conditions are possible. * Triple-digit heat index values could return Sunday afternoon and are likely early next week. && .UPDATE... Issued at 1043 AM EDT Thu Jul 11 2024 Skies are mostly sunny this morning, and temperatures are now approaching 80 degrees. A compact upper level shortwave trough is spinning east across IL. Morning SDF ACARS soundings show a significant warm layer near 600 mb, which will limit instability and any potential convective growth. With very light, somewhat chaotic low-level flow in place, the next several hours continue to look dry with temperatures warming into the upper 80s/near 90 this afternoon. As we move into the evening hours, weak low-level convergence and moisture pooling over the Lower Wabash should yield spotty convection. Isolated storms may be able to drift into our southern IN counties through the late evening hours. Cannot rule out a brief heavier shower in the northwestern CWA. Otherwise, dry conditions are likely to continue. && .SHORT TERM /THROUGH TONIGHT/... Issued at 322 AM EDT Thu Jul 11 2024 Skies are clear this morning thanks to sfc high pressure to our north building in over the region today. Still could see patchy fog develop in the predawn hours, especially in valley locations. Fog will mix out after sunrise and with the sfc high we will have mostly sunny skies through most of the day. Upper heights will gradually increase over the region allowing for temperatures to be warmer than they were yesterday by a few degrees. Highs will be in the upper 80s with a few locations reaching 90 by the afternoon. Even with gradually increasing heights, a weak shortwave trough will work through Indiana as it moves to the northeast. A few embedded vort maxes associated with this system will mainly work across Indiana but could be enough lift to develop a few isolated showers/storms across southern IN. Going with a general 15-25 percent chance of precipitation this afternoon before diminishing this evening given the diurnal nature of the activity. Mid-level inversion around 600mb will keep mid-level lapse rates low and be enough of a cap to keep most of the activity on the Indiana side. Skies will become clear again overnight with additional development of some fog, again in mainly low lying areas overnight. With the warmer temperatures and increased dew points, lows will be in the mid/upper 60s with more urban locations in the low 70s. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Issued at 322 AM EDT Thu Jul 11 2024 Weak upper trofiness will linger over the Great Lakes Friday into Saturday, allowing for waves of convection to possibly brush southern Indiana each day. Friday afternoon appears to be the best chance, but even then we're only carrying a 20% chance which barely extends south of the Ohio River. Overall heights aloft will be starting a slow rise, so temps will trend a couple degrees warmer each day, getting solidly above normal by Saturday. Otherwise dry weather continues through the weekend, as does the warming trend with mid 90s possible by Sunday afternoon, and enough humidity to push the heat index close to 100. Monday and Tuesday will be the hottest days of the upcoming week for at least some of the area, as H8 temps warm to near 23C. This could support mid to upper 90s, but the pattern looks active enough to our north that convection could create quite a bit of bust potential. Pulled back slightly from bullish NBM highs, but it will still be hot with most areas solidly in the mid 90s. This will likely push us into Heat Advisory territory one or both days, so stay tuned. By Wednesday the ridging breaks down enough for increased shower and storm chances and "less hot" temperatures. && .AVIATION /12Z TAFS THROUGH 18Z FRIDAY/... Issued at 647 AM EDT Thu Jul 11 2024 Skies remain clear this morning thanks to sfc high pressure over the region today. While current satellite nighttime microphysics imagery shows only some isolated spots of fog. Current obs do show only a few airports, like HNB, seeing fog this morning. While LEX/BWG are not out of the question, confidence is low but if any fog develops it should mix out by around 12-13z. The rest of the forecast calls for prevailing VFR flight categories with just FEW/SCT mid clouds towards the afternoon. Weak upper system will work into IL/IN this afternoon and this could spark a few isolated showers and storms into souther IN. Went ahead and put vicinity showers for this afternoon at HNB but kept the rest dry and that will continue into the overnight and tomorrow. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ UPDATE...EBW SHORT TERM...BTN LONG TERM...RAS AVIATION...BTN