FXUS63 KIWX 031729 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 129 PM EDT Thu Jul 3 2025 .KEY MESSAGES... - Slight chance (15-20%) for a stray shower or storm this afternoon and evening. - Hot and humid Friday into this weekend. - Somewhat better chances for showers and storms (40-50%) return Sunday into Monday. && .DISCUSSION... Issued at 358 AM EDT Thu Jul 3 2025 The region will continue to be impacted by weak disturbances into this evening with upper level heights slowly building overnight into the start of the weekend. As noted this past evening, a moderately unstable environment will be in place with MLCAPE in the 1000 to 1500 J/KG range along with steep low level lapse rates and inverted V soundings (DCAPE 900-1200 J/KG). A lack of clear triggers will result in another day of very isolated convective development that can form on any boundaries (lake breeze or remnant outflows from evening convection) or that move in from upstream. No more than slgt chc pops are warranted at this point mainly in the 20 to 24Z time frame. HRRR, which handled the evening scenario, does suggest some convection could persist in SW areas through 3 or 4Z but for now have not extended pops. As noted, upper level ridging will expand northeast Fri into Saturday with afternoon highs reaching their peak with highs likely into the 90s. Some signals exist in a few models that mixing of slightly lower dewpoints could occur each afternoon that would subsequently limit impacts from heat indices, but could also allow highs in some areas to overachieve. Have kept status quo for now and defer to later shifts to watch trends. The next trough will begin to edge in for Sunday and Monday bringing somewhat better chances for showers and storms. Model blends have backed off from likely pops as overall setup is similar to earlier this week with what will probably be limited coverage for the area and some seeing little rainfall. Temperatures trend back down somewhat for next week with highs back into the low to mid 80s and somewhat lower dewpoints with the NW flow re-establishing as well as a series of weak disturbances to bring periodic, diurnal chances for showers/storms. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 128 PM EDT Thu Jul 3 2025 A weak shortwave approaches from the northwest during the afternoon and evening hours tonight and may be able to set off an few isolated showers or thunderstorms before the day is done. One fly in the ointment is that an outflow boundary from yesterday's storms appeared to settled south of US-30 and that may completely remove today's chance for a shower or storm. As such, will lean entirely dry for this forecast. As a result, aside from some patchy morning ground fog, expect VFR conditions throughout. Wind-wise, our northwest winds veer overnight to become more southwesterly on Friday with a warm front now north and east of the area. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...Air Quality Alert from midnight tonight to midnight EDT Friday night for INZ020. OH...None. MI...Air Quality Alert from midnight tonight to midnight EDT Friday night for MIZ177-277. MARINE...None. && $$ DISCUSSION...Fisher AVIATION...Roller