Marine Weather and Tide Forecast for Munising, MI

DISCUSSION
Issued at 244 AM EDT Tue Apr 14 2026

Early this morning, low pressure is analyzed over IA, with a baroclinic zone extending northeast of this all the way through the northern LP. Forcing along this boundary was able to bring in quite a bit of rain to the UP tonight, but this is tapering off from west to east at this time; rain should entirely in the eastern UP into the pre-dawn hours. In its wake, with plenty of low-level moisture and light winds, areas of fog are developing across the UP, dense at times across the central and eastern UP. Otherwise, expect a mild night with temperatures only falling as far as the mid 30s near Lake Superior, and the upper 30s and lower 40s elsewhere.

Expect a period of generally drier weather conditions as weak ridging builds in from northern Ontario today through Wednesday.
Hopefully the slightly cooler air from northern Ontario and drier conditions will help to reduce the flooding risk across the area for the rest of this week. That being said, a couple of weak shortwaves moving through the Upper Midwest could bring additional showers and thunderstorms to the U.P. later this evening into tonight, the first grazing us to the north and the other to the south. Whether this shortwave brings precipitation into the U.P. or not will depend on the strength of the ridging from northern Ontario. In spite of lackluster QPF, however, flooding concerns will continue at least through today with the ongoing snowmelt and lingering impacts from this past night's rain. Otherwise, expect another warm day as temperatures peak in the 40s near Lake Superior, the 50s inland over the eastern UP, and the lower/mid 60s across the interior of the central and western UP. Temperatures fall back into the mid 30s to mid 40s tonight before peaking again in the 40s and 50s for most on Wednesday. Another shortwave low moving through the Upper Midwest could bring additional rain showers and thunderstorms to the area late Wednesday into Thursday. This remains conditional on the strength of ridging extending from Ontario, which could suppress this feature more to the south over the Lower Peninsula.

The warmest conditions of the weak move in on Friday as a cold air from northern Canada causes a robust cold front to develop across the central CONUS late this week. With PWATs looking to rapidly increase to around 1 inch in the warm sector via Gulf air ahead of the cold front, the NBM brings up to a 90% chance for temperatures greater than 70 to the western half of the U.P. as dewpoints have a 20 to 50% chance of exceeding 50 degrees (highest chances in the south central and interior west). Combined with intensifying southerly winds, this becomes a recipe for accelerating snowmelt on the snowpack that we have left across the area. Now, where guidance diverges for this week is whether or not a shortwave low lifts through the area before and/or after the arrival of the cold front.
Expect higher rain totals if a shortwave rolls through the area before the cold front moves through, as the cold front could bring additional showers and storms across the area into early this weekend. However, if a shortwave low rolls through the area immediately behind the cold front (like the latest deterministic Euro is suggesting), then the western half of the U.P. may be in for a significant wet snowfall event. Therefore, while the confidence is low at this time, we will keep an eye out to see if model guidance continues to converge on a solution. Regardless, there is fairly good agreement that colder temperatures and at the very least light snowfall will be seen over the northwest to west wind snow belts behind the cold front to end the weekend. Expect a transition to more normal temperatures early next week.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
Issued at 157 PM EDT Tue Apr 14 2026

While SAW and IWD start the 18Z TAF period out with low end MVFR cigs and VFR vis, CMX will continue to observe upslope LIFR to IFR fog and low cigs. All sites are expected to deteriorate to VLIFR tonight as widespread dense fog sets up over the region courtesy of ample low level moisture with weak flow.

MARINE
Issued at 244 AM EDT Tue Apr 14 2026

NE winds continue to gust to around 20kts across the western arm of the lake, but slowly decrease this afternoon. Meanwhile, areas of fog are developing across the lake this morning, and may be dense at times. Fog diminishes into the afternoon ahead of another batch of showers (with some thunder) moving over the lake his evening. Fog develops again tonight into early Wednesday. Otherwise, expect winds generally from the N to NE to remain below 20kts Wednesday through Thursday.

The main pattern shift for the period looks to come late this week through this weekend as a cold front approaches from the central CONUS. Winds intensify out of the south and southeast Friday, with over a 30% chance (highest over the open waters of the eastern half of the lake) of increasing to gales of at least 34 knots by Friday night before the cold front moves through the lake around the Saturday time period. Behind the cold front, as the strong cold air advection improves mixing of the higher winds aloft to the sfc, expect the winds to become northwesterly as gale chances increase up to 50% late in the day through Saturday night. In addition to the winds, some thunderstorms may be seen ahead of and along the cold front late Friday into Saturday.

HYDROLOGY
Issued at 244 AM EDT Tue Apr 14 2026

In response to the ongoing snowmelt and lingering impacts from heavy rainfall that occurred this past night, river rises and flooding of low-lying areas are expected/are occurring across Upper Michigan, particularly over the south central where another 1-2 inches fell.
While much of the area near Wisconsin lost the entirety of their snowpack, several inches to over a foot(!) of SWE remains over the Keweenaw and higher elevations of the north central U.P., as well as portions of the eastern U.P. upslope from Lake Superior over the northwest wind belts. Thus, while flooding concerns look to start dwindling over the areas near Wisconsin after Tuesday, expect continued snowmelt over the remaining areas to continue river rises over those areas with or downbasin from an area with notable snowpack remaining.

Because of this and the rainfall chances expected through the rest of this week, river flooding to bankfull conditions are being seen across several rivers across Upper Michigan. Starting with the Black River near Bessemer, the quick loss of snowpack with the rainfall yesterday has created Minor Flooding conditions which are forecasted to continue until Tuesday; bankfull conditions for the Black River look to continue until Tuesday night. Moving over to the Sturgeon River at Alston, Minor Flooding is currently being realized; with plenty of snowpack left to melt, expect the river levels to slowly rise the rest of this week into early this weekend. The high river levels at Alston and high flow at Prickett Dam may also bring elevated river levels to Chassell later this week; we will continue to monitor the local observations over there and issue products accordingly should bankfull and/or floodstage be achieved along the Sturgeon River at Chassell. Moving along to the Paint River at Crystal Falls, Moderate Flooding is expected starting late Tuesday as we move into Minor Flood Stage this evening. While not quite looking to get into Major Flood Stage, river heights are currently expected to get up to 8.5", which does start to approach the River Flood of Record. Moving into the Michigamme River basin, some bankfull conditions to Minor River Flooding looks possible at Bangston Bridge and Witch Lake late this week as the snowmelt in the basin progressively melts and increases flows with time. As for the Ford River, we are currently flirting with bankfull conditions this afternoon and could go over tonight given the chances for rainfall (some potentially heavy at times). Moving over to the Escanaba River, bankfull to Minor River Flood conditions are expected over the Middle Branch at Humboldt and the Eastern Branch at Gwinn. Given the recent call with one of the dam operators in Escanaba about the high flows, will continue to keep an eye on the snowmelt in the north central as rainfall moving through tonight could help to push- up cfs to hazardous levels. As for the Sturgeon River (Delta County)
at Nahma Junction, the recent heavy rainfall and snowmelt has caused river levels to exceed bankfull; I'd be shocked if the river doesn't go into Minor Flood Stage shortly as even the HEFS shows the river at about 100% for getting into Minor Flood Stage. As for the Manistique River, the increasing snowmelt and heavy rainfall recently (and potentially tonight) could bring above bankfull river levels, potentially causing ponding of water and inundation in low- lying areas near the river Tuesday and beyond; a Flood Advisory may need to be issued for this river's area of influence in the future.

MQT WATCHES/WARNINGS/ADVISORIES
Upper Michigan...
Flood Watch through Wednesday morning for MIZ001>007-009>014- 084-085.

Lake Superior...
Dense Fog Advisory until 8 PM EDT this evening for LSZ265>267.

Lake Michigan...
None.