textproduct: Marquette

KEY MESSAGES

- Light snowfall over the northwest wind snow belts goes offshore this afternoon.

- Lake enhanced snow returns tonight and will progressively transition to very fine flakes into Monday, susceptible to low visiblity and blowing. This and stronger winds of 20 to 45 mph will result in hazardous travel tonight and Monday for much of the area near Lake Superior. Winter Storm Warnings and Winter Weather Advisories are in effect.

- Very cold air moves into the area tonight through Tuesday morning,which will combine with winds to bring windchills of -10 to -25F to the area, with even colder values possible over the interior.

DISCUSSION

Issued at 250 AM EST Sun Jan 18 2026

Light lake effect snow continues over the northwest wind snow belts this morning before turning southwesterly this afternoon ahead of a Clipper low that is crossing the U.S./Canada border into the Northern Plains early this morning. The snowfall that has fallen thus far this morning has been extremely fluffy, with SLRs well above 30:1 being seen in the light snowfall areas (such as the local WFO). Within the northwest wind snow belts today, light and consistent snow showers could add another fluffy inch or two before they head offshore this afternoon. As for the rest of the U.P., some high SLR snowfall could bring an additional dusting ahead of the Clipper's arrival. As for highs today, expect them to be about 10 degrees colder in comparison to yesterday, only getting into the teens across the area.

As the Clipper develops over eastern Lake Superior this afternoon and continues building tonight until leaving Monday morning, expect moderate (1/2" per hour) to heavy (1+" per hour) lake enhanced snow showers to return to the northwest wind snow belts tonight, starting over the west and Keweenaw around 00z this evening. While the initial 'burst' of showers looks to be the heaviest, even though snowfall rates slightly dwindle behind the initial 'burst', expect high northwesterly winds of 20 to 45 mph to produce blowing snow problems across the northern tier of Upper Michigan tonight into Monday. The blowing snow problem will be amplified by the structure of the snow crystals as they transition from the fluffy 'traditional lake effect' we are used to, to a sand-like structure through the sector plating process. Thus, because of the transition to the more fine and granular snow type, expect the snow that does fall to be more easily lofted back into air as the lake enhanced snow showers continue tonight through Monday morning, eventually becoming pure lake effect once again over the northwest wind snow belts by the afternoon of Martin Luther King Jr. Day. Overall, the northwest wind snow belts could see anywhere between 2 and 6 inches tonight through Monday as SLRs tank close to 10:1 behind the initial 'burst' of snow showers thanks to dropping temperatures behind the Clipper limiting the DGZ to the sfc. However, given the reduced visibility concerns caused by the granular snowfall and high winds, Winter Storm Warnings and Winter Weather Advisories have been issued for this evening through Monday across the area as the blowing snow could bring near-blizzard conditions at times in the areas of blowing snow, especially near the Lake Superior shoreline where the winds will be the highest.

Besides the winter weather concerns tonight into Monday, the cold temperatures and stronger winds behind the Clipper are also looking to bring dangerously cold wind chills and temperatures to the area tonight through Tuesday morning. Wind chills down to around -25F are expected across the western area, with some spots in the interior possibly getting down to -30F or colder in some isolated spots. As of right now though, I've only issued a Cold Weather Advisory for the Keweenaw as wind chills Monday morning drop down to -25F for several hours there. While we could flirt with -25F wind chills across much of the western U.P. Monday morning, decided not to issue Cold Weather Advisories as it's not consistently lower than that for at least a few hours. However, the cold wind chills are mentioned in the additional details section of the Winter Storm Warnings and Winter Weather Advisories for the areas where they are pertinent. The colder weather will keep the highs on Martin Luther King Jr. Day in the single positive digits (save for maybe the lower teens in the east). While the lake effect is generally expected to lighten up on Monday, it is expected to continue Monday and Monday night over the northwest wind snow belts, potentially even having 1/2" per hour snowfall rates at times over the east. Thus, as the clouds across the rest of the U.P. clear across the areas outside of the northwest wind snow belts, expect even colder temperatures Monday night into Tuesday morning in comparison to tonight and Monday morning (lows in the negative single digits to negative lower teens in the interior west). However, with winds becoming lighter over the interior areas Monday night into Tuesday morning, we may struggle to get much colder than -25F for wind chills. Therefore, Cold Weather Advisory chances look lower Monday night into Tuesday morning as it will have to rely moreso on colder temperatures in the cloud-free areas and local cold pools (weaker wind speeds).

While we warm slightly into the middle of the week, lake effect snowfall and Clipper lows continue through the U.P. the rest of this week as colder than normal air continues to hang over us through the rest of the forecast period and beyond. With the CPC Day 8-14 Outlook still favoring below normal temperatures to the end of the month, expect this cold pattern to hold for the foreseeable future. In addition, guidance still shows even colder air than what's expected tonight through Tuesday morning coming next weekend. We will continue to keep an eye on this trend. However, while confidence is still low on this, it is increasing that we will see dangerously cold temperatures once again this next weekend.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 629 AM EST Sun Jan 18 2026

Light snow at all terminals this morning will lighten further as southwest flow shifts shower activity north of the terminals. VFR conditions will then largely prevail until widespread snow builds into the region this afternoon and evening. This will support at least MVFR or IFR conditions before falling to LIFR overnight as northerly and northwesterly winds increase to 25 to 30kts. Because of the type of snow will be especially susceptible to blowing in the wind, falling below airport minimums is possible.

MARINE

Issued at 321 AM EST Sun Jan 18 2026

Light winds of around 20 knots or less today give way to strong north to northwesterly winds of 30 knots to gales up to 40 knots tonight as a Clipper moves into the eastern lake this afternoon, develops tonight, and leaves Monday morning. Because of the strong winds caused by this Clipper and the Arctic air wrapped around it, Heavy Freezing Spray is expected across practically the entire lake this evening through Monday (and into Tuesday). Therefore, the Gale Watch has been upgraded into a Gale Warning and a Heavy Freezing Spray Warning has been issued for the large majority of the lake tonight through into Monday (the exception for the gales is in the far east where winds are now weaker than expected; only a few gale force gusts to 35 knots are possible). Do not be surprised to see the Heavy Freezing Spray Warning extended in later forecast packages as the very cold air and somewhat stronger northwest winds of 20 to 30 knots continues until the mid-week.

Eventually, we will see the winds drop down to 20 knots or less again, probably around Wednesday ahead of another Clipper low moving into the Upper Great Lakes. Behind this second Clipper low, expect winds to once again increase from the northwest late Wednesday and to hold to at least speeds of 20 to 30 knots into Thursday; don't be surprised if more Heavy Freezing Spray is seen again during this time period too.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Winter Storm Warning from 7 PM EST /6 PM CST/ this evening to 10 AM EST /9 AM CST/ Monday for MIZ001>003-009.

Cold Weather Advisory from 4 AM to noon EST Monday for MIZ001- 003.

Winter Weather Advisory from midnight tonight to 10 AM EST Monday for MIZ004.

Winter Storm Warning from midnight tonight to 10 AM EST Monday for MIZ005.

Winter Storm Warning from 1 AM to 7 PM EST Monday for MIZ006.

Winter Weather Advisory from 4 AM to 7 PM EST Monday for MIZ007-085.

Lake Superior... Gale Warning from 1 AM to 1 PM EST Monday for LSZ245>250-265- 266.

Heavy Freezing Spray Warning from 7 PM EST /6 PM CST/ this evening to 1 PM EST /noon CST/ Monday for LSZ162.

Heavy Freezing Spray Warning from 7 PM EST /6 PM CST/ this evening to 7 PM EST /6 PM CST/ Monday for LSZ240>244-263- 264.

Gale Warning from 10 PM EST /9 PM CST/ this evening to 7 AM EST /6 AM CST/ Monday for LSZ240>242-263.

Gale Warning from 10 PM this evening to 1 PM EST Monday for LSZ243-244-264.

Heavy Freezing Spray Warning from 1 AM to 7 PM EST Monday for LSZ245>250-265-266.

Heavy Freezing Spray Warning from 7 AM to 7 PM EST Monday for LSZ251-267.

Lake Michigan... Gale Warning from 1 AM to 1 PM EST Monday for LMZ221-248-250.