Marine Weather and Tide Forecast for Glen Arbor, MI

DISCUSSION
Issued at 123 PM EDT Thu Mar 19 2026

Pattern Synopsis:

Weak surface low over James Bay moving to the north and east as deeper troughing is forced eastward into northeastern CONUS and Atlantic Canada as a historic thermal ridge flexes across the western CONUS. The associated height rises with the aforementioned ridge will come knocking at various times over the coming days as a progressive / pseudo-zonal NW flow regime directs Pacific borne waves ejecting from a potent atmospheric river currently ransacking the Pacific NW into BC and Alberta. Result will be a series of low- moisture, warm advection driven waves traversing the Great Lakes through the weekend. With marginal temperatures overhead, this spells precipitation type concerns, though with limited QPF to work with. There is set to be a series of two waves passing through the region from now through this weekend: one tonight into Friday morning, and another later Saturday night into Sunday. I know what you're thinking
this sounds like a carbon copy of last weekend
but I can assure you, we will be contending with far less moisture, and thus impacts from these systems will likely be marginal at best.

The last of these systems will drag a bit of a more potent cold front through the region Sunday night, which will act as a bit of a reset by repressing some of the warmer air intruding into the region this weekend. The progressive pattern does remain in place, though, so anticipation is that we likely return to another series of waves passing through at some point next week, with more p-type concerns... with guidance honing in on this Tuesday and again later next week.

Details:

Should see more sunshine with time today as subsidence aloft associated with shortwave ridging picots over the region and 500mb heights increase. Highs top out in the mid 30s in eastern upper and far northern lower, likely 40 to 45 along and south of M-32... which should, at the very least, commence the process of melting ice off things across the southern CWA, but could be hindered if dewpoints stay below 32. The quieter stretch ends tonight as the first system passes through. This system will tap into some considerable WAA at the surface, though it looks to remain almost isothermal at 0C in eastern upper... so either looking at a smattering of 1-3" of wet snow across Chippewa County, with an inch or less south to the bridge due to poorer ratios and perhaps some sleet mixing in. At this time, will avoid the winter weather headlines given the marginality of this environment, but it would be ignorant to avoid mentioning potential for ice buildup on the Mackinac Bridge if any of this precip can fall as rain in the Straits with temps right at 32. Elsewhere? Looks like light rain, but expecting 0.10" or less, barring the steeper lapse rates aloft can manifest some convection... but guidance is bearish to that idea for now. Bigger story will be that once this initial wave of precip departs in the morning, we will be staring at temps well above freezing in the southern CWA with dewpoints to match, as a lingering drizzle holds overhead. This will for sure lead to any remaining ice on trees and structures to freefall / melt off. Above freezing temps likely poke into eastern upper as well, but will need to watch how slow this happens because there is a scenario where they get stuck at 31-32 and it is drizzly... collaborated with MQT about an advisory and decided confidence just isn't there, but isn't off the table later tonight with a little nowcasting.

Even warmer Saturday with drier conditions to start as the next system builds from the NW. Anticipating a rain-to-snow precip transition in eastern upper, with mainly rain / mix across far northern lower and rain farther south before ending as a skiff of snow by Sunday morning. Guidance isn't handling the amount of moisture with this system well, but regardless, looks like another marginal to perhaps low-end impactful system. More to come. Bigger story will be the cold front this particular system drags through, which will lead to highs in the 20s and 30s by Monday, with lows in the teens
Slowly moderating through next week
with highs poking back above freezing and into the 40s by midweek... which is pretty normal for late March and early April. Guidance continues to try to drag a weak system in Tuesday - Tuesday night, which could bring light wintry precip, with potential for a more organized and moisture filled system after midweek that could bring more mixed precip to the region. As always, much more to come in the next several days.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
Issued at 154 PM EDT Thu Mar 19 2026

Lingering MVFR CIGs across parts of the area this afternoon should give way to some more breaks in the clouds later today with many sites still expected to turn VFR for a time this evening. Low clouds will quickly move back in later tonight as a system works across the northern Great Lakes, bringing a mix of rain and snow along with IFR/LIFR CIGs and varying VSBYS (precip-type dependent). Grungy conditions may linger through at least midday Friday after the precip departs.

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