FXUS63 KIWX 081753 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 153 PM EDT Wed Jul 8 2026 .KEY MESSAGES... - Quiet today with highs in the mid/upper 80s. - Thunderstorms are likely Thursday evening and overnight. Isolated severe storms and heavy rain are possible with the best chances south of US-30. - Low chances for a few storms Friday and Saturday but turning dry and hot again next week. && .DISCUSSION... Issued at 151 PM EDT Wed Jul 8 2026 The main forecast concern over the next 24 to 48 hours continues to be the increased potential for convection w/ the passage of a weak mid-level short wave from Thursday evening through Friday AM. Little has changed w/ regard to the overall forecast thinking as confidence has increased in a more southeastward trajectory of the short wave, leaving the bulk of our CWA with very meager instability/shear profiles while the most ripe theta-e air mass (and better wind profiles) remain well to the south. Still think the focus area will remain south of US-30, but still some uncertainty here w/ mesoscale influences. As such, not comfortable trending PoPs downward at this point even though it seems central and southern IL/IN may be in a more favorable position. There remain some hints at a nocturnal MCS tracking across the region overnight, possibly impacting a set of our southern zones. Would anticipate heavy rain and localized flooding to be the primary hazard for this event, but a couple strong to marginally severe storms cannot be ruled out. /Hammer Previous Discussion (Issued at 138 AM EDT Wed Jul 8 2026): Another tranquil weather day today as broad mid/upper level ridging and low level theta-e sink remain centered directly over our CWA. Some patchy fog is possible this morning but limited near-surface moisture and some clouds in the SE will keep coverage and density in check. Highs today likely very similar to yesterday though perhaps a degree or two warmer given some subtle WAA and airmass modification under strong July sun. Lows tonight only in the mid/upper 60s due to slowly increasing low level moisture and a slightly warmer afternoon. Main forecast concern is thunderstorm potential Thu evening/ overnight. A weak (convectively modified) midlevel shortwave will approach the area Thu evening. A modest increase in low level SW flow ahead of this wave will bring better moisture into the region but it's worth noting far better theta-e surge remains focused over central and southern IL/IN. Midlevel lapse rates remain paltry and 0- 1km MLCAPE values likely struggle to get much above 1000 J/kg. Wind/shear profiles are also light with only around 20 kts of flow at 850mb and 0-6km bulk shear values are 25-30 kts at best. These parameters are marginally supportive of a few strong/severe storms. However, expect coverage of strong storms to remain low given weak mid/upper level support for upward ascent and better moisture convergence focused to our south. The best chances for a few strong storms currently appear to be roughly 22-04Z south of US-30 but that could change over the next 24-36 hours. Will also have to keep an eye on the overnight hours as some solutions send an MCS through central IL/IN late Thu night into Fri morning that could clip our southern zones with some heavy rain. Still think better chances for this will be just south of our area along the main moisture gradient but confidence isn't high and will watch this closely over the next few forecast cycles. The rest of the forecast is mainly quiet. A few SCT storms will be possible again late Friday and perhaps on Sat. Friday's chances will be dependent on exact timing and evolution of potential morning MCS but suspect a return to dry/stable NE flow behind this wave will keep most of the areadry for most of this time. Again, best chances for a stray shower/storm will be south of US-30. No severe weather expected given even more marginal instability and shear profiles. Large/strong (600+ dam) midlevel ridge then expected to develop over the central CONUS early next week and likely nose into our region at some point. Still some disagreement here with GFS keeping the ridge just to our west and allowing a backdoor cold front midweek while ECMWF (and to a lesser extent the Canadian) bulldoze the ridge into our region leaving us hotter and drier. Slight preference for the latter but overall no changes to the concensus initialization at this time. /AGD && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 107 PM EDT Wed Jul 8 2026 VFR conditions will prevail through the period. A few fair weather cu this afternoon and very high cirrus. Mid level clouds will start to increase on Thursday morning in advance of the next weather system. Light southwest winds will also start to increase on Thursday, but will generally remain around 10 kts or less. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...Air Quality Alert until midnight CDT tonight for INZ103-203. OH...None. MI...Air Quality Alert until midnight EDT tonight for MIZ078-177- 277. MARINE...None. && $$ DISCUSSION...Hammer/AGD AVIATION...Cobb