Marine Weather and Tide Forecast for Au Gres, MI

DISCUSSION
Issued at 144 AM EDT Sat Apr 18 2026

Cold front will be racing across Michigan this morning and midday, with a band of showers along/ahead of the attendant boundary. Subtle river rises and additional areas of flooding certainly possible given additional rainfall from Friday night lingering into early today, especially across northwest lower Michigan and eastern upper Michigan (rain and saturated soils across NW lower and rain and snowmelt in eastern upper). Nevertheless, the main batch of precipitation will move quickly eastward through this morning as winds shift sharply to the northwest, ending any joy from the previous warmer stretch of weather. Consequently, temperatures will fall through the day today with wind chills in the 20s and 30s through the afternoon hours. Trough aloft digs over the Upper Midwest into Sunday with secondary frontal boundary reinforcing the seasonably cold temperatures. A mix of snow showers and lake influenced snow showers will be possible later today into tonight and then on Sunday as the cold pool aloft moves over northern MI.
Snow showers will be possible along the secondary frontal boundary during the day on Sunday as well. Just some very minor accumulations possible as low level moisture quality looks suspect, but worth keeping an eye on. Winds increase behind the frontal boundary today, remaining breezy through Sunday.

Upper troughing pulls away early next week, with drier conditions overall as high pressure builds overhead on Monday. Quick moving upper trough across Canada and attendant boundary late Monday night into Tuesday may result in a slight chance for a shower, mainly to the north, but the thought is most of the area will continue with dry conditions.

Dry conditions continue through at least mid next week with increasing temperatures as high pressure builds in. The warming trend is expected to continue late next week due to significant height rises as ridging aloft aloft builds. All the while, significant troughing dives into the Pac NW and shifts east into the Northern Plains and vicinity. Resultant pattern would likely lead to increasing precipitation chances during the late week - next weekend time frame. Despite this increase in precipitation chances later next week into next weekend, hydro concerns will slowly relax through much of this upcoming week due to the mostly dry conditions and subsiding river levels.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
Issued at 435 AM EDT Sat Apr 18 2026

Gradually improving conditions with cigs increasing and scattering out to VFR through the day. More of the same overnight with generally higher based VFR producing cigs. May see a few light showers of both rain and snow fall out of this cloud deck, but with little to any impact. Gusty northwest winds today become more west and decrease in speed tonight.

HYDROLOGY
Issued at 144 AM EDT Sat Apr 18 2026

Anomalous and persistent rainfall in conjunction with snowmelt over the last week or two (amongst other longer scale hydrologic and meteorologic reasons) has resulted in historic river, small stream, and areal flooding in addition to a tremendous amount of road washouts across northern Michigan. Some areas are relaxing, at least to some extent, with the latest hydrographs and National Water Model inundation extent showing the Pigeon River and Sturgeon River with decreasing water levels and less inundation now compared to the last week. That being said, especially along the Sturgeon River from Wolverine up towards Indian River, there is likely remaining inundation and ponding of water based on how saturated the soils are. On the other hand, much of the rest of our major river systems continue to have significantly high water levels and flow with many streams continuing to exhibit flow (cfs) equal to or greater than a 1 in 50 year value. Another monumental river flood is occurring along the Manistee River, which continues with major flooding (currently 18.4 ft vs 16.9 ft which is the previous the record at gauge location SHRM4 (Sherman, MI)). Other locations that are currently experiencing flooding include the Thunder Bay River, the Au Grey River, the Black River, and the Rifle River, to name a few.
Additionally, elevated lake levels have resulted in flooding across the Tip of the Mitt.

The Cheboygan Dam is still being monitored at this time, along with a couple of other Dams upstream, although generally positive news has been reported at this time. The Bellaire Dam continues with a flash flood watch out of precaution at this time.

A general quarter to half an inch in spots with locally higher amounts (late Friday night into early today) will bump some river levels up some through the early portions of the weekend, mainly west of I-75. The snowmelt from yesterday and snowpack in general across the E UP makes them sensitive to any moderate precipitation as well through the early portions of today, although it is unclear how much rain will fall north of the bridge and how much flooding has or has not occurred in that area. Thus, leaving the Flood Watch for now through Sunday AM but one could argue to end it earlier, closer to MQTs end time. Additionally, soil moisture levels remain ~50-70% still across a good chunk of northern lower Michigan, so any moderate rain (Friday night) could cause impacts into this morning.
Even so, a general drying trend is expected, especially into much of next week, with river levels slowly relaxing through the week (some variation certainly depending on the river system), as noted by the HEFS 10 Day River Level Probabilities.

APX WATCHES/WARNINGS/ADVISORIES
MI...Flood Watch through Sunday morning for MIZ086>088-095-096.
MARINE...Small Craft Advisory until 5 AM EDT Monday for LHZ345>349.
Small Craft Advisory until 5 AM EDT Monday for LMZ323-341-342- 344>346.
Small Craft Advisory until 5 AM EDT Monday for LSZ321-322.