Marine Weather and Tide Forecast for Alpena, MI

DISCUSSION
Issued at 208 PM EDT Sat Apr 18 2026

Deep and anomalously cold longwave trough across the Great Lakes/Northeast into early week as western ridging pushes into western Canada. Additional Pacific energy pushing into the western CONUS early this week will bring lower heights back to western areas (and hopefully some precipitation), with induced higher heights and warming temperatures building from the midwest into the Great Lakes.
Overall, a much drier and quieter weather pattern developing across northern Michigan - after some lighter lake influenced precipitation chances this weekend.

Cold front has cleared northern Michigan with much colder temperatures taking hold across the area with wind chills in the 20s. Overlake instability will continue to increase tonight into Sunday as the 850mb cold pool sweeps across the northern Great Lakes. Inversion heights climb toward 7k tonight but moisture remains fairly limited. Expect scattered snow showers in west/northwest flow areas tonight with some minor accumulations possible (mainly on elevated and grassy surfaces). A secondary cold front moves through Sunday morning with a bit more mid level moisture - likely resulting in an uptick in snow shower activity. Minor snow accumulations will be possible, especially across the higher terrain and over parts of eastern upper. High temperatures only in the 30s in most areas (lower 40s southeast areas) with gusty winds resulting in wind chills in the 20s. Not a very springlike day across northern Michigan.

Clearing skies Sunday night as drier air moves into the area, A cold night, with most areas in the 20s and even some upper teens possible. One more well below normal temperature day on Monday with the 850mb thermal trough gradually pulling east of the area.
Another chilly night Monday night (20s to lower 30s).

Dry conditions through at least mid week with temperatures returning to seasonable levels in the 50s and 60s. At the same time, a deep trough dives into the western CONUS and begins to shift east into the Northern Plains. This will likely result in increasing precipitation chances later in the week for the Great Lakes.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
Issued at 127 PM EDT Sat Apr 18 2026

Mostly MVFR cigs today with -SHRA as a FROPA exits to the east.
W to NW winds of 5 to 15kts with G15 to 20kts at some terminals.
Winds will weaken to AOB 12kts after 03z. Skies will likely lift to VFR after 00z for most sites. Chances for -SHSN and strengthening winds after 12z for most terminals.

HYDROLOGY
Issued at 208 PM 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 18.1 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 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.

Rain Friday night into Saturday morning generally produced a quarter to a half inch of rain in many areas across northern Michigan, with localized one inch amounts in parts of the Manistee watershed. A general drying trend is expected for much of this upcoming 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...None.
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.