textproduct: Marquette

KEY MESSAGES

- Well above normal temperatures continue into the work week.

- Spotty rain and snow showers graze the UP this morning; patchy freezing drizzle or freezing rain is possible in the far eastern UP.

- An impactful winter storm will move into the Great Lakes region Tuesday night through Wednesday. Potential impacts include heavy snow, strong winds, and possible mixed precipitation, depending on the track and strength of the system.

- A Winter Storm Watch has been issued for Marquette, Baraga, Northern Houghton, and Keweenaw Counties Tuesday evening through Wednesday. This may be expanded elsewhere.

DISCUSSION

Issued at 338 AM EST Mon Feb 16 2026

Early morning GOES satellite imagery and RAP analysis reveal a shortwave working eastward across Ontario and Lake Superior. Lift ahead of the feature has been able to produce light radar returns across much of the UP, however, no precip has been able to make it to the ground as model sounding show a stout low to mid-level dry layer. Further upstream, an area of heavier precip currently (as of 3 AM EST writing this discussion) south of Duluth is pushing east across N-central WI. This may produce some light rain/snow as it presses into the s-central UP through daybreak. Interestingly, this blob managed to produce a few lightning strikes as it first developed. With the dry air in place, not thinking any heavy precip will reach the ground. Model sounding wetbulbs suggest any precip should be rain/snow or a mix. Otherwise, patchy fog/freezing fog is being observed across the south and east UP, having lifted at SAW/CMX just about now. Guidance is hit or miss on stubborn fog clearing through daybreak. Thinking fog should lift in the south as spotty precip passes by, lingering in the east the longest. Dry air filters in behind the weak cold front, scattering clouds and ushering in another warm afternoon. Patchy freezing fog/fog is expected to develop again tonight. Tuesday remains dry through the first half of the day before clouds and precip lift into the region ahead of the main story. More below on the upcoming winter storm.

Deep troughing invades the western CONUS and a very strong southwesterly jet develops from the Desert Southwest to the Upper Midwest. Lead wave ejecting across the Plains Tuesday night/Wednesday will be the main focus here. Strong and fairly long- duration overrunning WAA is forecast over the local area as this wave goes very negatively tilted, shears out, and stalls (in the multi-model mean). We'll have healthy deep moisture to work with as PWATs increase to near three quarters of an inch given your model of choice, as high as 300% of normal (99th percentile of NAEFS climatology)! Much of the deterministic and ensemble guidance paints us with a widespread 0.6-0.8in of QPF by 00Z Thursday, with higher totals up to an inch where lake and terrain enhancement occur (namely, the north-central UP and Keweenaw).

However, crucial differences continue to exist, despite being nearly 48 hours out from precip onset, that will determine precipitation type and amount. Most global models and their AI/Ensemble counterparts are still working towards the GEFS/GFS solution, with surface low pressure closing off near NW IA Tuesday evening, deepening to near/below 990mb over southeastern MN, and tracking into central or northern WI by Wednesday evening. Still, the AI ensembles remain the southerly solutions, Euro/ENS slightly north and west, and the GEFS/GFS as a happy medium. Also worth noting the 00z NAM decided to go north towards the Euro solution as well.

These differences place the heaviest qpf/snow axis anywhere from the UP/WI border (AI ensembles), to across the entire UP (GEFS/GFS) to the far eastern UP and Keweenaw / MN northshore and arrow head (Euro/NAM). The latter likely being the rainiest and or more mixed precip scenario, potentially more ice accumulations. Should the more southerly solutions pan out, ensembles suggest high probability of at least 6 inches (>70% chance) across much of the UP. Opting to run with the NBM for now, giving us a swath of moderate to heavy snow (4- 8") across the northern tier of the UP, less 1-4 the further south you go. Pockets of freezing rain are likely to mix in as the elevated warm nose pushes into the area late Tuesday/early Wednesday. The NBM suggests at least a 25-50% chance for a glaze of ice across the UP, mainly s-central and east, with lower probs (<20%) or amounts >0.1" before we change to snow. Snow character will be very wet (SLRs starting off 5:1 or less before rising to near 10:1 Wed PM) given the exceptional moisture values and model soundings mostly below the DGZ. This will curb blowing blow/blizzard threat however in combination with E/ENE winds upwards of 45 MPH along Lake Superior and in the Keweenaw, power outages and damage to trees will be the main hazard.

With all of this in mind, I've gone ahead and issued a Winter Storm Watch for Marquette, Baraga, N Houghton, and Keweenaw Counties, though this may be further expanded based on trends analyzed by the day team.

Respite from winter weather may be short lived (only 24-36 hours) as guidance suggests a secondary CO low lifting into the Great Lakes early Friday. Both deterministic and ensemble models are quicker to lift this one through the area and suggests less overall QPF than this first system. Additionally, overall track and system strength are not fully agreed upon. A more wintry airmass in place behind this next feature will keep in chances for lingering lake effect into next weekend while temperatures trend towards more or less seasonable values.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1238 PM EST Mon Feb 16 2026

Skies are largely clearing out this afternoon behind morning precipitation, though an area of lower cloud cover is moving across the northern UP at this time. This may bring occasional drops to MVFR later this afternoon to SAW. Meanwhile, some patchy fog/mist will also be possible at CMX over the next few hours. Expect fog to redevelop across much of the area tonight and bring IFR/LIFR cigs to the terminals 04-08z, then an improvement to VFR is expected after sunrise Tuesday.

MARINE

Issued at 338 AM EST Mon Feb 16 2026

Winds remain below 20 kts today through at least Tuesday morning before winds pick up ahead of our next system. Forecast models continue to show potential for a significant system to bring strong easterly winds Tuesday night into Wednesday, with up to 90% chance for gales and 25-40% chance for storms. Winds are likely to be elevated around 30 kt behind this system for the end of next week as colder air returns.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Winter Storm Watch from Tuesday evening through Wednesday evening for MIZ001-003>005.

Lake Superior... Storm Watch from Tuesday afternoon through Wednesday evening for LSZ162.

Gale Watch from late Tuesday night through late Wednesday night for LSZ242>250-263>266.

Gale Watch from Wednesday morning through Wednesday evening for LSZ251-267.

Lake Michigan... None.