Marine Weather and Tide Forecast for Harrisville, MI

SHORT TERM /THROUGH TUESDAY/
Issued at 158 PM EDT Mon Jul 14 2025

Pattern Synopsis/Forecast: Nearly zonal flow across the western Great Lakes today becomes more weakly ridged during the day Tuesday in advance of low amplitude troughing set to sag across the middle of the country during the midweek time frame. A weak/decaying frontal boundary/surface trough is in the process of crossing the eastern U.P. and Straits area early this afternoon, but with limited fanfare. By tonight, attention turns to low pressure gathering strength upstream over the northern Plains. Warm front stretching eastward from this system should be in place to our north by Tuesday with northern MI entirely in the warm sector setting up for a very warm day (albeit still somewhat smoke/haze dependent). This boundary will provide the focus for additional waves to ride along as it slowly sags south across the Great Lakes through midweek.

Forecast Details: Plenty of haziness as a result of wildfire smoke continues across the state today, but with only limited surface visibility restrictions this afternoon as mixing heights have risen.
Lingering shower/storm chance across eastern upper this afternoon, primarily along the aforementioned decaying boundary and the developing lake breeze convergence axis. Environment could potentially support some small hail and gusty outflow winds from any storms able to sustain themselves for a period of time. These non- zero chances extend into far northeast lower as well.

By Tuesday, increasing heat expected to be the main story. Still some hazy skies, especially early in the day, but hi-res smoke allowing guidance suggests highest concentrations of smoke should displaced well downstream. Highs expected to range from the upper 80s to low/mid 90s (warmest in downsloping areas). Touch cooler at the beaches, of course. As initial wave of low pressure rides along that nearly stalled boundary to our north, it's conceivable as few showers/storms work their way into sections of the eastern U.P. at times. Suppose a stronger storm or two can't entirely be ruled out, especially if any upstream convective clusters are able to work this far east.

LONG TERM /TUESDAY NIGHT THROUGH MONDAY/
Issued at 158 PM EDT Mon Jul 14 2025

Pattern Forecast: Upstream slow-moving/quasi-stationary boundary continues to very slowly sag south across the western Great Lakes through the midweek time frame. Mid-level shortwave(s) embedded within larger scale troughing and attendant waves of sfc low pressure expected to continue ride along this boundary at times.
Still plenty of uncertainty regarding the evolution and speed of this system, but suffice to say that midweek will feature the highest precipitation chances of the forecast period. High pressure settles into the region behind this system for late week into the start of the weekend. Additional shower/storm chances follow toward the tail end of the period as another wave and associated surface reflection barrel across the northern tier of the CONUS.

Forecast Details: As noted by the prior forecaster, pretty high likelihood that more numerous showers/storms prevail across northern Michigan through the midweek time frame. Lower confidence in coverage/timing, potential for heavy rain and severe weather chances. Current confidence lies in a solution that features scattered shower/storm development during the day Wednesday in an increasingly muggy airmass. This followed by potential for more numerous/widespread precipitation later Wednesday night into Thursday morning. Given flow nearly parallel to that slow moving boundary, training appears to be a possibility lending credence to a locally heavy rain threat -- this sufficiently supported by WPC's Marginal Risk for excessive rainfall Wednesday/Wednesday night.

Trending drier and cooler post frontal passage to wrap up the work week with highs back into the 70s. Additional precip chances follow late Saturday into Sunday.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
Issued at 729 PM EDT Mon Jul 14 2025

Mainly VFR. A SHRA is lingering near CIU, but will be gone in a few hours. Not impossible for CIU to dip to MVFR vsbys at times tonight due to HZ/BR, but VFR is more likely. Some cumulus for cloud cover Tuesday.

Light winds tonight. Sw winds become a bit breezy by Tue afternoon.

APX WATCHES/WARNINGS/ADVISORIES
MI...Air Quality Alert until midnight EDT tonight for MIZ016>018- 020>036-041-042-086>088-095>099.
MARINE...None.