Area Forecast Discussion

KEY MESSAGES

- Cooler and a bit windy on Tuesday, likely resulting in some dangerous swimming conditions

- Seasonable temperatures with some additional rain chances at times to for the remainder of the period

DISCUSSION

Issued at 1109 AM EDT Mon Jul 27 2026

Pattern Synopsis/Forecast:

All focus initially directed shortwave trough/upper level speed max and attendant rather weak surface reflection dropping southeast into the region within broad upper level northwest flow...part of remarkably persistent Intermountain West/High Plains centered upper level ridge/heat dome and northeast NOAM long wave troughing configuration. This wave will continue to kick off showers and thunderstorms across the region this afternoon into early this evening. Large area of Canada originated high pressure set to follow through the mid-week period. While current NOAM upper level flow regime will wax and wane at times into the weekend, overall configuration will remain...continuing the northwest flow aloft.

Primary Forecast Concerns:

Nearly all focus directed at convective evolution into this evening. Secondary emphasis on beach hazard concerns Tuesday and temperature/additional precipitation trends through the remainder of the period.

Details:

Mature MCS tied to above mentioned wave racing southeast across eastern Wisconsin...simply following axis of intense instability gradient and pre-existing differential heating boundary. Western periphery of this activity pushing into northern Lake Michigan, but most organized and intense storms remain to our west. Expect this storm cluster to continue southeast into the southern Lakes. Another very impressive complex noted over portions of central Lake Huron, likely putting out some gusty winds and isolated pockets of large hail over the big body of water. Radar trends suggest this activity will stay offshore. Do expect some additional showers and storms to percolate across our area into this evening as primary upper level support passes overhead. Could see a few strong to severe storms, capable of producing some gusty winds and large hail. Again, best course of action is to continue to monitor radar trends into this evening.

Rain threat ends overnight as high pressure builds southeast into the northern Lakes. Dry and seasonably mild Tuesday, with marginally gusty northwest winds within tight pressure gradient between eastern Lakes low and the southeast diving high pressure. These winds will allow for some decent wave development, resulting in hazardous swimming conditions on at least some of our beaches of northern Lake Michigan. High pressure drops directly overhead Tuesday night into Thursday. Could see some decently chilly early morning temperatures Wednesday and Thursday...when some of our traditional colder interior areas could make a run into the 40s. Airmass modification will be substantial by the daytime hours of Thursday, with plenty of sunshine helping temperatures recover back into the 80s. Additional passing waves may bring some additional shower/storm chances Friday into the start of the weekend. As one can imagine, uncertainty is high, with plenty of time to work out those details in the coming day. Seasonably mild weather to continue through the weekend.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 1154 PM EDT Mon Jul 27 2026

SHRA/TSRA activity is moving south and east of our TAF sites. Periodic low clouds will be seen overnight, mostly MVFR, but IFR/LIFR conditions have already settled in at CIU. Improving to VFR Tuesday morning, with breezy north winds developing.

APX WATCHES / WARNINGS / ADVISORIES

MI...Beach Hazards Statement from 6 AM EDT Tuesday through Tuesday evening for MIZ031. MARINE...Small Craft Advisory from 6 AM to 11 PM EDT Tuesday for LHZ347>349. Small Craft Advisory until 6 PM EDT Tuesday for LMZ323-342- 344>346.