textproduct: Northern Indiana

KEY MESSAGES

- Highs through Monday will be seasonably warm in the 80s. Humidity levels will vary with the next 2 days being the most pleasant.

- The best chances for showers and thunderstorm should remain south of the area until Saturday.

- Heat and humidity return for the second half of next week with heat indicies possibly reaching 100 degrees or higher.

- A Beach Hazards Statement is in effect for the beaches along southeastern Lake Michigan into this evening. Waves of 4 to 6 feet will create dangerous currents.

DISCUSSION

Issued at 343 AM EDT Thu Jul 17 2025

Cold front was readily apparent in sfc obs as well as radar, extending from Coldwater to Plymouth. Somewhat of a drop in dewpoints noted with even some brief gustier winds (Benton Harbor gusted to 45 mph). The front will progress SE, but eventually slow down and stall out south of US-24 as upper flow flattens. Theta-e gradient will remain in this vicinity during peak heating, which may allow for a few popup showers or storms. Suspect main path of convection will remain even further south, but for now will limit pops to slgt chc in the far south. Lower dewpoints will continue south with some models indicating dropping into the 50s, especially north. Regardless, even a drop into the low 60s will be a nice relief, albeit brief. The NW flow and already noted somewhat gustier winds will set the stage for a high swim risk

Theta-e gradient/baroclinic zone will edge slowly back north Saturday with 70 dewpoints making a return along with scattered to possibly numerous showers and storms. Pop up convection could happen at any point, but best chances likely to occur from upstream convection or its remnants moving east into the region along with a weak upper level ripple depicted in the models. SWODY3 has introduced a marginal risk (1 out of 5) for location along and south of US-30. Of greater concern could be the copious amounts of moisture that will likely be in place with risk of one of more rounds of showers/storms that could bring an increased flooding risk.

Upper level ridging will slowly increase into next week with the 594 dm upper level high edging slowly north and west and strengthen further. This will likely result in any convective chances remaining north of the area as 700 mb climb above 10 C, especially capping the entire area and allowing the region to bake as highs make a run back into the lower 90s and dewpoints in the 70s. Heat indices Wednesday and Thursday will likely top 100 degrees with limited overnight relief. In addition, "corn sweat" will be in full swing, potentially adding to dewpoints locally. Will need to monitor this period as model signals seem to be fairly consistent.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 500 AM EDT Thu Jul 17 2025

A cold front was moving east across northern Indiana at the start of the TAF period. The front was just entering the corner of northwest Ohio and extended southwest into northern Indiana. The front was still west of FWA at 09Z. Winds were gusting from the northwest just behind the front. Most ceilings were MVFR behind the front, although SBN and EKM both had IFR ceilings. MVFR ceilings at SBN should linger deep into the afternoon given a strong frontal inversion per BUFKIT. Improvement is likely to VFR at both sites as drier air eventually spreads across northern Indiana.

IWX WATCHES/WARNINGS/ADVISORIES

IN...Beach Hazards Statement through late tonight for INZ103. OH...None. MI...Beach Hazards Statement through late tonight for MIZ177-277. MARINE...Small Craft Advisory until 2 AM EDT Friday for LMZ043-046.