textproduct: Marquette

KEY MESSAGES

- Mixed precipitation develops from west to east this morning. A light glaze of ice is possible across the west and central UP (60-80% chance). Untreated roads and surface may become slippery.

- Expect temperatures to rise above freezing by afternoon with precipitation becoming rain from west to east. Snow accumulations of up to 3" are possible in Keweenaw and Luce counties, less than an inch elsewhere.

- Another period of light mixed precipitation is possible tonight as a cold front pushes south through the area.

- A somewhat active pattern continues next week, with multiple systems bringing additional precipitation chances to the U.P.

DISCUSSION

Issued at 317 AM EDT Sat Mar 21 2026

Early morning GOES satellite reveals an expansive ridge across the western and central CONUS. A ridge riding shortwave is working southeast from the northern High Plains towards the Upper Great Lakes. Temps closer to home are hovering near freezing. This aforementioned shortwave will kick off a more progressive pattern across the region as the western ridge breaks down and zonal flow allows the passage of additional waves.

Widespread precipitation is expected over the northern and eastern UP this morning and early afternoon, starting as rain in the west, a freezing rain and snow mix central and mainly snow in the east. A transition to rain will occur from west to east through the day with all of the UP above freezing by late afternoon, the west reaching as warm as 50-55F. Snow accumulations will generally be less than an inch, however Keweenaw and Luce counties could see 1-3". Untreated roads may be slippery until warmer air arrives in the afternoon due to any wet snow accumulations and potential light glaze of ice. Latest HREF and REFS suggest a 60-80% chance for a glaze of ice for much of the west-central and Keweenaw through the morning into the early afternoon.

A cold front will push south across the area tonight into Sunday bringing another chance for precipitation to the area. A relatively narrow band of rain and snow is expected to develop along and immediately behind the cold front as it drives southwards across the UP. CAM guidance now largely places the greatest precip axis just along and south of the UP-WI border, or missing the UP altogether. Soundings largely show a transition from rain to snow, though cannot rule out a brief period of mixed precip.

On Sunday through Monday a sfc high pressure will build into the area from Manitoba and Ontario. It will be cooler with highs in the 20s to low 30s, 5 to 10 degrees below average. There is a chance that we could see some lake effect precipitation with northerly flow over the area. Sunday morning inversion heights are fairly low so would expect light snow showers or possibly freezing drizzle for typical northeast wind upslope areas (terrain of Marquette and Baraga counties). Sunday night inversion heights are somewhat higher, up to 4kft but 850mb temps of -10C to -12C make for a marginal deltaTs. Any snow accumulation should be minimal.

Active weather continues into the midweek period with multiple chances for accumulating precipitation, however, no substantial system look to impact the UP at this time.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 750 AM EDT Sat Mar 21 2026

Radar shows precipitation spreading into Upper Michigan from the west this morning, with KCMX and KSAW reporting IFR/MVFR conditions while KIWD remains VFR. Expect these conditions to persists through much of the day, with mixed precipitation including -SHSN and -FZRA giving way to -SHRA later in the afternoon as temperatures rise above freezing. Conditions trend up towards prevailing MVFR this evening in a brief lull between systems, but a passing cold front tonight will lower conditions back to IFR through the end of the period in another round of mixed precipitation.

MARINE

Issued at 317 AM EDT Sat Mar 21 2026

Winds shift southeasterly by this morning and increase to 20kt and as high as 25kt over the central part of the lake, near and east of the Keweenaw. A cold front will push through tonight with northeast winds to 30kt developing and continuing into Sunday morning. Probabilities for gale force gusts with this front remain low, 10- 20%, and not anticipating any gale headlines at this point. As high pressure builds over the lake on Sunday winds will diminish through the day. Winds will ramp up again on Monday night as they become southerly 30+ kt in response to an approaching low pressure. There is a 20-40% chance for winds to reach or exceed gale force Monday night through Tuesday morning. Winds shift northerly to 30kt as a cold front drops south behind the departing low pressure Tuesday night into Wednesday, moderate freezing spray will be possible.

MQT WATCHES/WARNINGS/ADVISORIES

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