FXUS63 KIWX 041742 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 142 PM EDT Mon May 4 2026 .KEY MESSAGES... - Warm and breezy today with highs well into the 70s. - Chances (20-50%) increase for scattered showers and storms mid afternoon today into tonight. A few storms could become strong to severe (wind/hail). - Cooler with a soaking rain developing Tuesday afternoon into Tuesday night (70-90%), best chances along and southeast of the US 24 corridor. - Cool midweek through the weekend with occasional low chances (20-30%) for scattered rain showers. && .DISCUSSION... Issued at 227 AM EDT Mon May 4 2026 A good deal of sunshine and ongoing warm advection within renewed 30 kt plus 925-850 mb southwest flow will push highs well into the 70s today. Moisture advection and resulting CAPE magnitudes will remain somewhat limited in this regime however with sfc dewpoints only reaching the upper 40s to mid 50s within a well mixed boundary layer by later this afternoon. This likely limits coverage/intensity of widely scattered convection (20-40%) mid afternoon into mid evening near a northward advancing warm-frontal like feature, and incoming weak mid level impulse lifting through from the Mid MS Valley. With that said, cannot completed rule out an isolated wind threat given up to 1000 j/kg of MLCAPE and inverted-V type soundings, with hail also not out of the question given corridors of 25-35 knots of deep layer shear (hence the SPC Day 1 Marginal Risk). A longwave trough dropping into the Midwest does push a slowing cold front into the area from nw to se late this evening into Tuesday morning. Increasing (50-70%) shower/storm chances will accompany this feature and/or composite outflow. There may be enough lingering MUCAPE and strong enough pre-frontal flow to support an isolated wind threat late evening into the early overnight, mainly northwest of the US 24 corridor. Cooler air settles in behind the sfc front on Tuesday. The elevated portion of the front stalls along/south of the US 24 corridor by Tuesday afternoon-evening with rain and embedded thunder likely (70-90%) blossoming as a frontal wave develops along it. Latest guidance hints at the potential for a sharp cut-off to the rain into nw IN and sw MI as drier surges in under the frontal slope. Latest NBM did cut into PoPs/QPF here. Ensembles continue to lock in aggregate troughing and northwest flow midweek through the upcoming weekend with below normal temperatures and periodic opportunties for rain showers as disturbances drop through in cool cyclonic flow. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 142 PM EDT Mon May 4 2026 A warm frontal feature moves northward from central IN/IL area this afternoon into the evening ahead of a cold front sliding southeast from the Western Great Lakes. These features bring chances for showers and thunderstorms later this afternoon and evening with damaging wind, hail, a low chance for a tornado as the main threats. In any thunderstorm, heavy rain can lead to the visibility and ceilings dropping down into MVFR conditions. The tendency for these storms will be to go from a severe threat to a heavy rain threat as we move into the overnight period. Winds are expected to be south of the southwest this afternoon into tonight before becoming more northwesterly. Gusts today to 30 kts calm down tonight and weaker winds occur on Tuesday with the front sliding through. Additionally, some LLWS will be possible tonight. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...Small Craft Advisory until 8 PM EDT this evening for LMZ043- 046. && $$ DISCUSSION...Steinwedel AVIATION...Roller