textproduct: Marquette

KEY MESSAGES

- Light lake effect snow showers are expected across the eastern UP this morning and early afternoon.

- A somewhat active pattern continues this week with multiple systems bringing additional precipitation chances to the Upper Great Lakes. However, high-impact winter weather is not expected.

- Near normal to slightly below normal temperatures should limit and slow down the snowmelt across the area this week.

DISCUSSION

Issued at 236 AM EDT Mon Mar 23 2026

Early morning GOES satellite reveals mostly clear skies across the Upper MS Valley under sprawling sfc high pressure. Closer to home some weak mid-level shortwave action is keeping mostly cloudy skies overhead the northern Great Lakes. An uptick in lake effect snow showers is currently ongoing in Alger county as RAP analysis indicates mid-lake boundary layer convergence and 850 mb temps cooling between -12 to -14C. CAM guidance suggests scattered LES showers persisting across the east half through much of the morning and into the early afternoon, mainly between Munising and Grand Marias. Bufkit soundings out of Munising show plenty of dry air below a ~2kft DGZ with lake induced equilibrium levels only punching 6-7kft, so while a few brief moderate snow showers are possible, thinking the scattered nature of LES and overall unimpressive profiles will keep accumulations below 1", with isolated 1-3" possible under more persistent showers/bands. Otherwise, as high pressure and drier air continue to build towards the Great Lakes today, expecting cloud cover to scatter out with a diminish in LES activity east. should be a pretty nice afternoon with light winds and temps warming towards the low 40s in the west. Lake effect clouds and light northerly winds off Lake Superior will work to keep daytime highs in the mid to low 30s across the north central and east.

An active pattern with multiple opportunities for accumulating precipitation sets up the rest of the work week as height rises across the southwestern US allow the passage of several ridge riding shortwaves into the Great Lakes. The SW ridge then breaks down later this week, sending a deeper trough into the region Thursday/Friday.

The first shortwave quickly digs through Ontario late tonight through early Tuesday morning. Isentropic ascent ahead of this feature will force light snow across the eastern UP. Given antecedent dry conditions a the bulk of the forcing help up near James Bay, thinking precip may struggle to reach the ground across the western half of the UP. Overall, an inch or two of wet snow is possible in the east half by early Tuesday afternoon. Another quick batch of wet snow sneaks in Wednesday as our next weak wave moves through, though amounts again look to be low impact, coming in below an inch across the north-central and east.

More attention may need to be given to the Thursday/Friday timeframe where guidance hints at a more compact clipper and tighter pressure gradient that may drive additional travel impacts in gusty winds and falling snow. Latest NBM still doesn't bode well for much snow, continuing to highlight a meager 20-40% chance for >2" across the northern tier of the UP. Global models are in fair agreement that modest cold air advection will take place following this clipper into Friday morning, characterized by north to northwest winds and 850 mb temps falling below -13C. Lake effect snow impacting the Friday morning commute will be another target of opportunity for future forecast packages.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 742 AM EDT Mon Mar 23 2026

Observations from around Upper Michigan show mostly VFR conditions at area terminals this morning, save for some variable IFR/MVFR conditions at KCMX as a few robust lake effect bands linger over the Keweenaw and in the eastern UP. Expect these to diminish through later this morning, yielding VFR conditions through the rest of the period. NW winds around 10 kt will back southwesterly and increase to around 15 kt with 20-25 kt gusts this evening ahead of the next clipper low passing north of the area tonight. This will introduce some -SHSN back into KCMX late in the period as cigs start to lower after 06z Tue.

MARINE

Issued at 236 AM EDT Mon Mar 23 2026

NW winds continue backing to the W and then SW today, remaining below 20kts throughout the day before picking up out of the south overnight ahead of another Clipper. There is around a 25-40% chance of achieving low-end gales over the eastern lake, mainly the Canadian waters late tonight through early Tuesday morning. A second weak clipper elevates S to SE winds to near 25 kts Wednesday. Winds less than 20 kts are expected late Wed through early Thursday. A more compact clipper then works through the Great Lakes Thursday into Friday. A strong cold front following the clipper's passage looks to bring northerly low-end gales early Friday. At this point, probability for Gales >35 kts remains low (<25%).

MQT WATCHES/WARNINGS/ADVISORIES

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