Marine Weather and Tide Forecast for Marquette, MI

SHORT TERM /THROUGH SATURDAY/
Issued at 409 AM EDT Fri May 23 2025

Early morning RAP analysis and WV imagery highlights broad mid level troughing over the E CONUS with the main wave over the Great Lakes and a tighter shortwave pivoting NE along the New England coast. At the sfc, a stronger sfc low ~998mb associated with the shortwave is just S of ME with the weaker departing low ~1005mb over Lake Huron.
Also, high pressure is beginning to extend S over the Dakotas/MN from Manitoba/N Ontario. With ample low level moisture, this supports mostly cloudy skies across the UP with upslope flow -shra noted on the radar mosaic over the N tier of the UP. This cloud cover and shra has moderated temps so far in the low to mid 40s, but additional cooling into the mid to upper 30s is anticipated by around sunrise in the interior W. The remainder of today will be more or less the same as the departing weaker sfc low phases with the deeper lifting low toward ME. Expect breezy NE winds with highs in the mid 40s to mid 50s, warmest S-Central.

High pressure to the W continues to build in overhead tonight, helping diminish -shra chances. That said, model soundings show decent low level moisture to carry 15-25% PoPs for N upslope flow - shra over the N-Central and NE UP. Temps tonight have a better shot at dipping ever so slightly cooler, settling into the mid 30s to low 40s. Some frost is possible interior W.

Warmer on Sat with highs in the 50s. Gradually increasing high pressure and weakening low level wind flow supports lighter winds at the sfc, mainly less than 15 mph. While the sfc pattern would lean toward drier weather returning, a mid level shortwave over N MN Sat morning pivots along the WI/MI state line into Sat night, yielding some additional chances for -shra near WI Sat afternoon/evening.

LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/
Issued at 318 PM EDT Thu May 22 2025

As we head into the weekend, surface low pressure will be moving over New England, with high pressure centered over northern Ontario extending ridging into the Upper Great Lakes. This will keep us under northerly flow through the weekend, but a moderating airmass will have 850mb temperatures climbing to around 0C with a gradual warming trend kicking off. Temperatures still start off generally in the 30s both mornings, but highs range in the lower to perhaps mid 60s with partly cloudy skies across much of the UP Saturday and Sunday. Nearer to Superior, onshore flow should keep temperatures in the 50s. Meanwhile, with light winds, more breaks in the clouds, and temperatures dropping into the mid 30s or lower in the interior- western UP each morning, frost could become more widespread early Saturday and Sunday, potentially necessitating headlines in future forecast cycles.

Our warming trend continues into next week. In this period, the airmass at 850mb will warm to +3-4C Tuesday before cooling again Wednesday night below zero C. This will support daytime temperatures potentially well into the 60s across most of the UP Monday and Tuesday, and generally in the 50s near Lake Superior. Daytime mixing and the dry airmass Monday/Tuesday will also yield RH values dipping into the 30s and perhaps 20s. At the moment, elevated fire weather conditions are not expected given lighter winds...but even this could prove problematic as lake-breeze development could cause sudden shifts in wind direction. Following several generally dry days, this could still be a period worth watching.

Midweek onwards, midlevel troughing or perhaps even a cutoff low ejects out of the Plains, with an associated surface low closing off over the central Mississippi valley and heading towards the Lower Great Lakes. This could graze us with some rain showers by the end of the forecast period, but confidence is low as ridging may hold strong over us and suppress this next feature too far to our south for any impacts to be felt here. Otherwise, expect temperatures to continue to trend upwards, reaching the 70s across much of the UP by Thursday afternoon.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
Issued at 733 AM EDT Fri May 23 2025

Abundant low level moisture will keep flight restrictions at CMX/SAW through the duration of the 12Z TAF period while IWD improves to VFR by late this afternoon. CMX will see a period of IFR this morning/early afternoon with some upslope -shra before returning MVFR the remainder of the day. CMX then looks to fall back to IFR tonight. SAW will see the worst conditions with mainly IFR during the TAF period; some LIFR cigs are possible tonight (25% chance).
Otherwise, breezy NNW winds will impact CMX/SAW with gusts up to ~20 kts through this afternoon.

MARINE
Issued at 318 PM EDT Thu May 22 2025

Low pressure over the Lower Great Lakes today moves into New England Friday into the weekend. On the back side of this feature, primarily north to northwest flow persists over Lake Superior at least through the weekend. Wind gusts of 20-25kts, occasionally up to 30kts, remain common across the eastern half of the lake today through tonight, gradually falling back below 20kts by late in the day Friday. Winds remain light through the weekend and into next week.

MQT WATCHES/WARNINGS/ADVISORIES
Upper Michigan...
Beach Hazards Statement until 4 PM EDT this afternoon for MIZ005.

Beach Hazards Statement through this evening for MIZ006.

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