Marine Weather and Tide Forecast for Sebewaing, MI

UPDATE
Issued at 946 PM EDT Wed Apr 23 2025

Low pressure over northern Lk Superior will continue eastward tonight. This system drags a cold front into northern MI late tonight. Just ahead of this front, showers and some t-storms have been developing this evening over central upper MI and eastern Superior. This is at the nose of a weak-ish unstable plume, with MlCape values of 300-400j/kg. The most widespread precip and heaviest QPF should scoot by just to the north of eastern upper, but Chip/Mack Cos will see a substantial glancing blow at a minimum. Pops have been boosted in eastern upper MI, though the tail end of this activity will depart before the late overnight.

Less vigorous and less widespread convection is seen on an e-w axis over central WI. The surface cold front makes further southward progress into northern MI late tonight, and the weak instability plume moves overhead. Lingering southerly flow off the deck interacts in part with that boundary, supporting an increase in showers and t-storms here overnight, especially in the south. A vaguely stronger storm or two is possible, mainly in nw lower MI, with mainly a small hail threat. But any leftover marginal severe threat has been banished from all of MI by SPC.

SHORT TERM /THROUGH THURSDAY/
Issued at 246 PM EDT Wed Apr 23 2025

Pattern Synopsis/Forecast: Broad area of weakening low pressure sits upstream this afternoon -- centered near the MN/Ontario border, but stretched southward across the upper and mid-MS Valley. This system's warm front currently stretched over the central U.P.
southeastward over Lake Michigan and into lower Michigan. Trailing cold front over southwest WI/IA. Morning convection over northern IL and IA has decayed with time, but now making some progress into western lower MI. Continued moisture advection this afternoon into tonight over northern MI will aid in isolated to scattered shower and potential thunderstorm development late today into tonight. Low pressure becomes centered near the Quebec/Ontario border Thursday morning with the aforementioned trailing boundary effectively stalling overhead for Thursday. This should lead to an impressive temperatures gradient across the forecast area and additional low chances for showers/drizzle, particularly for areas near and north of the boundary.

Forecast Details: Little in the way of sensible weather through the morning hours earlier today, although increased mid-high cloud has been the rule associated with deeper moisture advection and decaying convection arriving from the southwest. Initial focus for shower/ storm chances revolve around incoming lingering convection working its way into areas west of Grand Traverse Bay. Latest near-term trends suggest this activity makes slow inland progress while continuing to decay over the next handful of hours. Non-zero thunder chances with a couple of lightning strikes noted over northern Lake Michigan over the last hour as steepening mid-level lapse rates aid to promote 200-400 J/kg of elevated instability building across parts of the forecast area. Increasing deep layer shear of 40-60 kts suggests that if any storms area able to materialize (largely inhibited by a lack of meaningful lift), an instance or two of large hail can't entirely be ruled out. Strong-severe storms aren't the expectation by any means, but simply not close enough to zero to not mention.

A few additional isolated showers or storms remain possible through the evening, although it's expected that the vast majority of the forecast area remains dry. For the second half of the night, highest chances for showers/storms again focuses near and south of M-72 between 06-12z. Some signals that slightly better instability folds into the area through this time frame with at least some potential for more numerous rumbles of thunder and additional low-end strong storm chances. Some patchy fog development possible late tonight as well.

For Thursday, a nearly stationary boundary expected to be situated over northern lower MI should result in a fairly impressive temp gradient across the forecast area. Highs expected to range from the 50s far north to the low-mid 70s far south. Some low potential exists for an isolated shower and/or patchy drizzle near and north of the boundary, but not sold on just how widespread any drizzle will be.

LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/
Issued at 246 PM EDT Wed Apr 23 2025

Pattern Synopsis/Forecast:

A stationary front will be shunted northward as a surface low pressure tracks into the region from the southwest at the start of the period. As the low progresses across the Mitt, pressure gradients will tighten between surface high pressure building from the northwest and the aforementioned low, to support pretty breezy conditions Friday/ Friday night as well as widespread rain and thunder chances. Guidance is still not overly excited about any severe storms Thursday night into Friday, but is still something to watch in the coming cycles.

Aforementioned surface high pressure looks to build into the region this weekend making for beautiful summer-like weather with clear skies and warmer temperatures. Saturday's high temperatures are forecasted to be cooler with highs in the mid 50s to mid 60s and then trend warmer Sunday with highs in the 60s and 70s (cooler by the lakeshores). Warming temperatures will continue into next week with forecasted highs into the upper 70s, to even perhaps the low 80s for southern locations. Another system is set to impact the region early next week with additional shower and thunder chances.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
Issued at 730 PM EDT Wed Apr 23 2025

All sites VFR presently. Lower cigs will develop very late tonight, especially in northern areas. Expect CIU to be IFR for part of Thursday morning, and PLN MVFR. CIU and mbL are the most likely to see some light fog late tonight (MVFR vsbys).

Light southerly winds into early Thursday, becoming nw during the day.

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