Marine Weather and Tide Forecast for Marquette, MI

DISCUSSION
Issued at 136 PM EDT Sun Aug 16 2026

A cold front pushed through the UP today bringing a fast moving band of showers to parts of the central and eastern UP. Behind the front low level moisture, enhanced by Lake Superior, was bringing light showers and drizzle to the upslope areas of the western UP. Surface observations showed temperatures were cooler today through it was humid, with temperatures 60s and 70s with dewpoints not too far behind the temperature; it warmest in the east. Breezy northwest winds had developed behind the front, especially closer to Lake Superior. The combination of winds and waves will continue to bring hazardous swim conditions this afternoon and evening for the beaches along Lake Superior east of Marquette (a Beach Hazard Statement remains in effect into the evening hours). Precipitation amounts from overnight into the day were mainly light, less than a tenth of an inch through parts of the Keweenaw received upward of a third of an inch. GOES satellite data showed some eroding of the clouds over western Lake Superior but overall clouds remained widespread across the U.P.

Northwest flow aloft is expected for tonight through much of the week with a seasonable airmass providing highs in the mid to upper 70s and lows in the 40s and 50s. Another cold front will move through the U.P. Monday night into Tuesday bringing the chance for showers (up to 50%) and a slight chance (20%) for thunderstorms.
Showers and thunderstorms will develop along a cold front upstream during the daytime hours Monday but will weaken significantly as they move into the UP Monday night as the airmass will be fairly stable and little in the way of large scale forcing is available to maintain the showers/storms. There is still variance with the ensembles and deterministic guidance regarding the timing of the cold front. LREF joint probabilities for MUCAPE>=500 J/kg and bulk shear >= 30kt are around 60% for counties bordering Lake Michigan / Bay of Green Bay and around 30% for the central and eastern counties along Lake Superior. The EPS is largely are contributing the higher probabilities as it has the slower solutions but some deterministic guidance are also falling into the slower timing. The NAMNest and RRFS showing updraft helicity tracks in the aforementioned area of high joint probabilities. Thus a few strong storms can not be ruled out at this time through the probability for severe thunderstorms remains low (less than 5%).

Behind the front dewpoints fall further into the upper 40s to low 50s for much of the UP Tuesday night through the end of the week.
With the drier airmass, light winds and clear skies low temperatures on Tuesday and Wednesday night could dip into the upper 30s over the interior west.

The next chance of showers will be late in the week as northwest flow brings another front through the area. Widespread, impactful precipitation is not expected at this time thus not expecting appreciable improvements to the drought conditions over the far south and west.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/
Issued at 114 PM EDT Sun Aug 16 2026

Low cloud cover continues to lead to MVFR restrictions at all terminals to start off the forecast period, but a return to VFR is expected by 19Z at IWD, 20Z at CMX, and 22Z at SAW. Brisk NW winds are expected during the daytime hours today, with sustained winds in excess of 10 kt at all sites (with gusts to 20+ kt expected at CMX)
before becoming 5 kt or less after sunset tonight. Some patchy MVFR fog is possible mainly at SAW early Monday morning, otherwise VFR prevails the remainder of the forecast period.

MARINE
Issued at 136 PM EDT Sun Aug 16 2026

Lake Superior - Overall expect benign weather conditions this week with only a few periods with winds near or slightly above 25kt. 20- 30kt winds this afternoon along and east of the Keweenaw will diminish through the evening. Another period of Northwest winds to 25kt near/east of the Keweenaw is expected of Tuesday, otherwise winds will generally be less than 20kt. Precipitation is possible Monday night and Friday but the chance for thunder is low (less the 20%) and a drier airmass should keep the lake fog free.

Northern Bay of Green Bay and northern Lake Michigan - Overall expect winds less than 20kt for much of the upcoming week. A cold front moving across the lake the afternoon will bring northwest winds behind it to 25kt through early evening but will diminish this evening. Thereafter winds will be predominately southerly with the exception of northerly winds on Tuesday behind a passing cold front.
Showers and thunderstorms are possible Monday night into Tuesday (50% chance). A few storms could be strong on Tuesday but the chance for severe thunderstorms is low (less than 5%). Showers are possible again on Friday.

MQT WATCHES/WARNINGS/ADVISORIES
Upper Michigan...
Beach Hazards Statement until 10 PM EDT this evening for MIZ005-006.

Lake Superior...
None.
Lake Michigan...
None.