Area Forecast Discussion

KEY MESSAGES

- High waves and strong currents are expected at southeast Lake Michigan beaches through Wednesday night. Stay dry when waves are high.

- Dry, cooler and less humid conditions expected through the remainder of the week.

DISCUSSION

Issued at 133 PM EDT Tue Jul 21 2026

A secondary cold front moving in from the northwest will kick off another round of showers and storms across the forecast area this afternoon. With dewpoints in the upper 60s to low 70s and temperatures rising into the mid 80s, conditions are ripe for a few storms with heavy rain. MUCAPE is 2000-3000 J/kg and there is moderate shear around 40 kts, so cannot rule out isolated damaging wind gusts, but confidence is low in severe weather. However, this front will sag to the south-southwest through the evening and subsidence and cooler/drier air will follow, suppressing convection.

Winds will shift to the north behind the front tonight, and lake enhanced clouds and showers are expected to develop off of southern Lake Michigan late tonight and into Wednesday with the cooler air aloft and warmer lake temperatures in place. Lows on Wednesday morning will be in the 50s while parts of Lake Michigan surface water temperatures are currently in the lower 60s to lower 70s. Not expecting much of accumulation from any of the showers but will be enough to keep areas near the lake damp on Wednesday. Otherwise mild and dry conditions will prevail through Saturday with the storm track staying south of the area. High pressure will start to build in on Sunday and temperature will warm back into the upper 80s. Moisture will also return with a chance for showers and storms Sunday night and Monday as a series of shortwaves is forecast to ride over the top of the ridge into the Great Lakes and Ohio Valley.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 710 PM EDT Tue Jul 21 2026

Lake-enhanced cloudiness and perhaps a few light showers will be the primary aviation highlight through the TAF period, generally resulting in BKN-OVC sky coverage around 3500-5000 feet AGL tonight through much of the day on Wednesday. Confidence remains low whether this will result in MVFR ceilings, particularly at KSBN. Have opted to continue with a VFR forecast with 3500 foot ceilings, though occasional lowering to 2500-3000 feet cannot be ruled out.

IWX WATCHES / WARNINGS / ADVISORIES

IN...Beach Hazards Statement through Thursday morning for INZ103. OH...None. MI...Beach Hazards Statement through late Wednesday night for MIZ177-277. MARINE...Small Craft Advisory until 1 AM EDT Thursday for LMZ043-046.