textproduct: Marquette

KEY MESSAGES

- Gusty southwest to westerly winds of 25 to 35 mph are expected this morning, diminishing through the afternoon. The strongest winds are expected in the Keweenaw and by the lakeshores.

- Widespread snowfall is expected Tuesday through Wednesday, with lake effect snow trailing downwind of Lake Superior Wednesday night.

- Another widespread snowfall and windier event may impact the U.P. Thursday night and Friday.

DISCUSSION

Issued at 357 AM EDT Mon Mar 9 2026

Early morning GOES satellite imagery and RAP analysis reveals a ~988mb surface low located along the MN/Canada border supported by a 110-120kt upper level jet streak translating east across the Upper Great Lakes. Throughout much of the night, regional radar returns have been present in the UP though 10-15F Td-depressions have prevented nothing more than light rain/sprinkles mainly in the east half. Further upstream however, a line of "stronger" convection looks to cross western Lake Superior over the next hour into the western UP. As this skirts the northern tier over the next few hours, a quick hit of light rain and maybe a rumble of thunder may be seen. Otherwise, as this sfc low quickly works its way through the northern lake and into Quebec by the early afternoon, expect an uptick in breezy southwest to west winds. Similar to yesterday, another warm and dry day is favored this afternoon under partly cloudy skies with warm temps near 50F. NBM deterministic guidance suggests portions of the south-central may punch 60F. Further norther, the Keweenaw may struggle to reach 50F given breezy west winds off the lake.

Unfortunately, today will be the final day of False Spring as wintry weather returns and a colder pattern begins to take shape late tonight into Tuesday morning and further through Wednesday. The overall progression over this period will begin with a surface high transiting northern Ontario tonight while a weakening surface low moves through the Northern Plains and a second surface low organizes and lifts out of the Southern Plains on Tuesday. Preceding swath of isentropically forced snow associated with the fizzling northern stream's surface low will stretch across the region Tuesday morning into Tuesday night as the two features begin phasing. Confidence in this first round of light snow is rather low, as CAM guidance varies on the placement and translation of this snowband as it reaches the western UP/Keweenaw around midnight tonight before moving southeast across the central UP through Tuesday morning. Overall, light snow less than an inch is the most likely scenario, though if a stronger banded feature takes shape (as suggested by a few of the 00z CAM runs), locally 1-2" may be realized in the west or closer to the UP/WI stateline.

By Wednesday, the remaining surface low will lift northeast through southeastern lower Michigan, with its inverted trough/deformation axis stretching northwestward into the Upper Great Lakes under the support of left exit jet dynamics tied to a 150kt jet streak near 300mb. The 850mb airmass looks to slowly cool through this transition, reaching near -7C Wednesday morning, with additional cooling to near -13C Wednesday night. This will help reinforce snowfall Wednesday with a possible lake enhanced component, under northerly flow, before transitioning to lake effect overnight downwind of Lake Superior into the traditional northwest wind snowbelts.

Hazards with this event will include the potential for light to moderate, wet snow, becoming fluffier through the day Wednesday, when the greater synoptic forcing is present and better snowfall rates are expected. Deterministic guidance and their ensemble counterparts continue to highlight uncertainty in snowfall amounts through Wednesday. The most recent NBM 25th-75th percentile suggests a wide range of solutions, the 25th being 0-2" and the 75th being 3- 8" (highest central and east). Meanwhile the latest GEFS/ENS probs for at least 3" of snow by 00z Thursday show similar disagreement, being the more aggressive solution (60-90% chance for at least 3", 20-50% for 6" east and central).

Attention then turns to another potentially impactful clipper working through the region late Thursday into Friday. Over the last 12-14 hours, guidance has come into better agreement that the sfc low center will track south of the UP through early Friday morning, placing Upper Michigan within the area of greatest synoptic scale forcing and favored lake enhancement. Differences exist, however, in the track and strength which ultimately lead to variance in the greatest QPF axis. Both the GEFS/EC ENS suggest a 30-50% chance for at least 3" of snow across much of the central UP by Friday evening, the NBM a 30-60% for 4". Additionally, given forecast area pressure rises/falls associates with the low's passage, ensembles point towards a windier system with gusts >40 mph (30-50% chance)

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 720 AM EDT Mon Mar 9 2026

VFR conditions prevail through the daytime hours, then MVFR restrictions settle in mainly from 06Z onwards as snow develops over the area. Confidence in snowfall is highest at CMX and IWD, but lower ceilings are nevertheless expected at SAW late tonight. Meanwhile, westerly winds remain gusty at CMX and to a lesser extent IWD this morning. Gusts up to 20kts at IWD and up to 30kts at CMX gradually fall back through the morning and afternoon while shifting over to the W/NW.

MARINE

Issued at 357 AM EDT Mon Mar 9 2026

Breezy southwest to west winds 30-35 kts are expected this morning as a fast moving low pressure works east through the northern lake this morning and early afternoon. Latest guidance pegs a 25-45% chance for gusts >35 kts in the open waters eat of the Keweenaw this morning. Opting to leave the current Gale Warnings in place despite the low to medium probs. Winds lighten through the day, likely falling below 20kts lake-wide by evening.

Tuesday evening into Wednesday night, another period of elevated winds is expected, with potential for gales Wednesday and Wednesday night. Best chances for gales are mainly east of the Keweenaw Wednesday night. Another stronger system looks to move through the Upper Great Lakes late Thursday, potentially resulting in high end gales and storms Thursday night and Friday. Afterwards, winds lighten to near or below 20kts lake-wide Saturday.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... Gale Warning until 2 PM EDT this afternoon for LSZ244-245- 264>266.

Lake Michigan... None.