textproduct: Marquette

KEY MESSAGES

- A wintry mix of rain, freezing rain, and snow is expected tonight into Friday morning. Trailing freezing drizzle is possible Friday morning. Minor impacts to roadways are possible, especially across the east half where wet snow and/or a light glaze of ice may accumulation on road surfaces.

- Warmer and near-to-above normal temperatures expected for the rest of the week. High temperatures ranging from the mid-30s to 40s today increase to widespread 40s to near 50 Friday.

DISCUSSION

Issued at 317 PM EDT Thu Mar 19 2026

Quiet conditions continue into this evening with the passing high pressure over the Great Lakes. As this gives way to the east, a shortwave and clipper system move in from the northwest tonight into Friday. Temps settle into the 30s to upper 20s early tonight, coldest east. WAA and isentropic ascent with the clipper low set up a wintry mix of rain, freezing rain, and snow, particularly over the northeast tier of the CWA. QPF ranges from trace amounts over the interior west and south-central up to 0.25 to 0.40", highest amounts east. P-type initiates as just rain/snow this evening over the west, but starts to include chances for light freezing rain overnight as surface temps drop to or just below freezing. Model soundings favor primarily snow over the east and Keweenaw County, but this translates to more of a wintry mix moving southwest toward WI. Wet snow amounts up to 1 inch in Keweenaw County and up to 3 inches in Luce County are expected. A light glaze of ice is possible on untreated surfaces over the central and parts of the Keweenaw. Model soundings also indicate potential for trailing drizzle / freezing drizzle Friday morning. Held off on any Winter Weather Advisories with mainly minor impacts anticipated, but an SPS may needed for Friday morning as slick spots on roadways and sidewalks could impact the morning commute. The rest of the day Friday sees temps warm up into the mid 30s to mid 40s as dry weather and some sunshine return. Friday night lows are expected in the mid 20s to near freezing.

The mid level ridge upstream over the western CONUS flattens on Saturday, allowing for a wave to track from the PAC NW to the Great Lakes the remainder of the weekend into Monday. This features a weak low pressure tracking from northern MN over the UP late in the day Saturday into Saturday night. A deeper low follows it up, tracking from the northern Rockies along the southern end of the Great Lakes Basin through Sunday night. There still remains uncertainty regarding the exact timing and track of these features, however a similar set up to Friday is anticipated with the initial precip on Saturday. Afternoon highs are expected in the 30s and 40s, warmest near WI. Light amounts of wet snow far north and east is favored with more rain toward WI where the profile is warmer; a wintry mix of rain/snow is anticipated in the middle. PoPs continue Saturday night through Sunday as the deeper low tracks to the south and a cold front presses south overhead. Freezing rain is possible Saturday night (20% chance). Probabilities of wet snowfall totals exceeding 3 and 6 inches in 24 hours are between 20-50% and 15-30% respectively, lowest near WI. Lows Saturday night will be in the mid 20s to near freezing, warming up on Sunday into the upper 20s to mid 30s, warmest south.

850 mb temps behind this system fall to between -10C and -14C, possibly yielding light trailing lake effect precip. Moisture content in model soundings is unimpressive and high pressure descending in from the Canadian Prairie quickly disturbs the northerly wind field over Lake Superior. So scattered lake effect cloud cover and mostly dry weather is more likely on Monday. Highs will be similar to Sunday, but warmest near WI state line. Dry weather likely does not hold long as a clipper quickly tracking across northern Ontario re-introduces rain/snow PoPs Monday night through Tuesday. A more notable wave exits the Rockies mid to late next week, sending a deeper low pressure near or across the Great Lakes. That said, model spread is pretty significant to dig into the details.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 834 PM EDT Thu Mar 19 2026

VFR conditions to continue into tonight. However, a weak disturbance will move through tonight, bringing freezing rain/snow chances to both CMX and SAW as well as a LLWS threat to all TAF sites. With the onset of precipitation, MVFR will become the prevailing flight category with periods of IFR through at least Fri 12Z. Look for improvement back to VFR after that.

MARINE

Issued at 342 PM EDT Thu Mar 19 2026

A passing clipper system tonight increases southerly winds to 15-30 kts, strongest over the east half of the lake shortly after midnight. Winds quickly become northwest in the wake of the low, remaining below 20 kts through Saturday.

Another system moves into the Great Lakes Saturday/Sunday. Winds increase out of the northeast to 20-30 kts by Sunday morning as the pressure gradient increases and a colder airmass descends over the lake. Probabilities for gales have fallen to 20% or less with this system. Winds settle below 20 kts again Sunday night, remaining light through Monday with a passing high pressure. Expect some light to moderate freezing spray to accompany this colder airmass and elevated period of winds/waves. Another wave moving through Ontario on Tuesday may support a period of 20-30 kt south becoming west winds Monday night and Tuesday. Should this period pan out, moderate freezing spray would be expected, but confidence is low.

MQT WATCHES/WARNINGS/ADVISORIES

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