textproduct: Marquette

KEY MESSAGES

- Light snow is expected in the far southern U.P. near Menominee today. Amounts will remain below 1 inch.

- There is a slight chance (15-20%) for a snow/freezing rain mix tonight over the east and north, a light glaze on untreated surfaces cant be ruled out.

- A cold front on Tuesday brings northwest wind gusts up to 25-35 mph near Lake Superior and in the Keweenaw. A Gale Watch is in effect for the east half of Lake Superior.

- The next possible widespread precipitation arrives late Christmas Night, continuing into Friday. That said, plenty of uncertainty remains on precipitation type and amounts. Holiday travelers should monitor the forecast for updates and possible impacts.

DISCUSSION

Issued at 350 AM EST Mon Dec 22 2025

Early morning RAP analysis shows the 1033 mb high now over the Virginia's, moving the ridging previously overhead to the Lower Great Lakes. Mostly clear skies and near calm winds tonight have allowed for temps to fall into the single digits in the interior west, warming into the teens as you move toward the east and by the lakeshores. The strengthening LLJ and WAA to the south will slow further cooling as high clouds stream overhead. This also supports a round of light snow grazing the far southern UP today. Given the brief and unimpressive moisture as well as the lack of moisture present within the DGZ, snowfall amounts likely will remain below 1" (75% chance). A dusting could be seen as far north as Iron Mountain and Escanaba, but confidence in that is low (~20% or less). Temps warm up into the upper 20s to mid 30s. A secondary round of snow, and slight chance of freezing rain, is possible mainly over the north and east this evening into tonight as a shortwave slides in from the west (15-20% chance). Guidance once again is unimpressive with moisture and the forcing is hit and miss. Lows tonight in the 20s.

On Tuesday the primary shortwave and surface low track through northern Ontario, just north of Lake Superior. This may support light snow late tonight into Tuesday morning over the north (15-20% chance), but a majority of the deterministic solutions keep precip out over Lake Superior and closer to the low in northern Ontario. Guidance does agree on a tight pressure gradient setting up in the system wake Tuesday afternoon. This in tandem with CAA will support widespread west becoming northwest winds of 10-15 mph Tuesday afternoon and evening. Stronger winds of 15-25 mph are expected near Lake Superior and in the Keweenaw where gusts of 25-35 mph are expected. There is a 20-40% chance of gusts exceeding 40 mph in the Keweenaw and eastern lakeshores per the latest NBM. This also may support some isolated LES showers, but low inversion heights and limited moisture (all beneath the DGZ) limit any accumulations.

Dry weather is favored Tuesday night into Christmas Eve while a mid level ridge builds over the Plains. Lows Tuesday night will be in the teens to low 20s. Attention then turns to shortwave and low pressure system tracking from the Northern Plains through the Great Lakes late Christmas day into Friday. Plenty of uncertainty remains in the mid level ridge's impact on shortwave track, which in turn keeps notable spread in the possible surface low track. Resulting variability in temperatures aloft leave snow, freezing rain, and rain all on the table yet. The NBM currently has a 15-30% chance of 4" of snow and a 10-30% chance of 0.01" of ice by 7 PM EST Friday. Those with travel plans Christmas or the day after should keep an eye on the forecast. Further troughs tracking through the region into the weekend leave PoPs in the forecast.

Temps through most of the extended forecast will peak 5 to 10 degrees above normal during daylight hours. Temp anomalies overnight have a greater spread between 5 and 20 degrees above normal, with the greatest difference noted in the interior west. This puts highs in the 30s with overnight lows in the upper teens and 20s. Closer to normal temps return late this weekend into early next week with highs in the teens to mid 20s and lows in the single digits and teens.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 633 AM EST Mon Dec 22 2025

VFR conditions will prevail through the morning hours at the TAF sites. Warm and relatively moist air will advect north by late morning into the afternoon bringing a period of IFR cigs to the TAF sites for a few hours, mentioned in TEMPO groups. VFR conditions should return for the early evening hours but MVFR cigs will develop overnight at SAW and CMX, with the clouds at IWD possibly staying SCT and therefore VFR. There is a slight chance for light snow at CMX and SAW tonight but any precipitation will be light and should not impact vis (below MVFR).

MARINE

Issued at 350 AM EST Mon Dec 22 2025

Light winds hold mainly below 15 kts today across the lake. East becoming south winds 15-20 kts are expected this evening through tonight as a low pressure system approaches from the west. This system tracks across the northern edge of the lake on Tuesday, and with the passing cold front, west winds increase to 20-30 kts lakewide Tuesday morning. 30-40 kt winds are likely over the east half Tuesday afternoon and evening (~70% chance). Hoisted a Gale Watch as confidence in occurrence is high, but timing could use a bit more clarity. Chances for 40-45 kt gusts are between 25-50% east of the Keweenaw.

Winds quickly fall below 20 kts from west to east Tuesday night out of the northwest as high pressure moves in from the west. Winds increase to 15-25 kts out of the south Wednesday afternoon as the high departs. Strongest winds are expected over the east half of the lake. The next period of elevated winds to 20-30 kts arrives late Thursday into Friday when a low pressure system tracks through the Great Lakes region. That said, timing and track of the low pressure system remains uncertain.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... Gale Watch from Tuesday morning through Tuesday evening for LSZ243>251-264>267.

Lake Michigan... None.