Marine Weather and Tide Forecast for Onekama, MI

DISCUSSION
Issued at 302 AM EDT Mon Aug 3 2026

A fairly quiet stretch of weather is expected to start the week as a departing upper-level disturbance continues to pull farther into the Northeast. In its wake, expanding mid-level ridging and accompanying surface high pressure settle across the Great Lakes, providing a few days of quiet weather to begin the forecast period. The larger-scale pattern remains progressive with the aformentioned ridge gradually shifting east as another wave and its associated cold front approach the region mid-week.
Beyond that, guidance continues to favor a return to broader troughing across the region through late week into the start of the weekend before indications of a flatter, more zonal flow looks to emerge toward the end of the period.

Clearing skies overnight combined with light winds and lingering low- level moisture has allowed areas of patchy fog to develop this morning, especially near inland lakes, rivers, and other favored low- lying locations. After morning fog dissipates, abundant sunshine and dry conditions are expected both today and Tuesday with today's afternoon high temperatures generally in the 70s to around 80 degrees. Overnight lows tonight will dip close tot he 40s across the typical interior cold spots, with the remainder of northern Michigan settling into the mid 50s. As the surface high pressure shifts east, developing southerly return flow and continued sunshine should support a modest warmup Tuesday, with many locations climbing into the low to mid 80s.

Forecast confidence begins to decrease somewhat by Tuesday night into Wednesday as the next aforementioned shortwave and attendant front move toward the area. Increasing large-scale ascent associated with favorable upper-level jet dynamics will support a growing chance for showers and thunderstorms, with the greatest coverage likely occurring sometime Wednesday as the front crosses the region. Exact timing remains the primary forecast challenge and will ultimately dictate how much instability can develop ahead of the boundary. Current indications suggest enough instability for scattered thunderstorms, with the potential for a few stronger storms should greater daytime destabilization materializes. Moisture also increases ahead of the front, supporting locally efficient rainfall rates where thunderstorms persist.

Conditions settle back down heading into the latter half of the week as cooler air filters in behind the front beneath broader cyclonic flow aloft. While the overall pattern does not appear particularly active, weak disturbances rotating through the upper-level trough may be sufficient enough to generate low-end shower chances from time to time. Seasonable temperatures look to persist through the end of the week.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
Issued at 631 AM EDT Mon Aug 3 2026

Aside from some shallow patchy fog for the next hour or so, VFR conditions expected across the northern Michigan terminals through the 12Z TAF valid time. Generally light winds are anticipated as well.

APX WATCHES/WARNINGS/ADVISORIES
MI...None.
MARINE...None.