textproduct: Marquette

KEY MESSAGES

- Daytime highs rebound well above freezing this weekend into early next week, supporting gradual snowmelt across the U.P.

- Light snow showers are possible along the northern U.P. this afternoon.

- Thunderstorms (southern UP) and widespread rainfall is becoming increasingly likely late Monday and Tuesday.

DISCUSSION

Issued at 220 PM EDT Sat Mar 28 2026

Afternoon KMQT radar returns show that the eastern UP lake effect snow showers have wrapped up, and upstream to the west, light reflectivities are observed over the far western UP associated with a RAP-analyzed weak 700mb shortwave, though a surface dew point depression of 15 degrees shows that there is a ton of dry air for any potential precipitation to combat, and the fact that IWD's 16Z METAR shows CLR conditions under 12kft shows that the dry air is quite deep. Despite this dry air, much of the CAMs show that light snow should make it to the surface over the northern half of the UP this afternoon, so some accumulations of less than an inch have been added to the forecast with this package, with no impacts anticipated. Expect high temperatures to climb above freezing across virtually the entire UP today, with the MI/WI state line climbing to around the 40 degree mark. The aforementioned dry air will cause surface RHs to fall to around 30% along the state line as well, with wind gusts up to 25 mph causing at least some fire weather ingredients to come together. However, the window for RHs to fall below 30 percent is only a couple hours and the NOHRSC snow pack analysis still shows over an inch of snowpack for the entire UP, save for some patches in Ontonagon County and around Ironwood. Still, this is a sign of the transition in the seasons and a good time to brush up on fire weather situational awareness.

A quiet spell then works over the UP tonight through Monday morning given the absence of any shortwaves and the presence of significant dry air. This will allow high temperatures to climb significantly especially in the interior west, where NBM highs are in the mid-50s. While the snowpack for much of the UP will survive, given observed SWEs in much of the northern half of the UP in excess of 1 foot, the interior western and southern UP may start to see larger areas with no snowpack as those are the areas NOHRSC shows with the least SWE. Snowmelt is a long-range concern at this point given that some small rivers and streams are already approaching or exceeding bank full with plenty of water suspended in the snow that is yet to melt.

Next week looks to be an active one. Monday through Tuesday, a 500mb trough will push just north of the US/Canada border from the Rockies to the Prairie. This will help organize a surface low of around the upper 990s mb over southern MN by 00Z Tuesday. Ahead of that low, the warm front looks to push showers over the region around 00Z Tuesday, with some spread in the solutions on what those showers produce. Chances of freezing rain is around 20% Monday night into Tuesday morning per the GEFS/GEPS, while snow will be limited to the Keweenaw at around 30-40% chances there and around 20% for the rest of the UP that is north of Marquette. Further south could be more interesting, with the surface low's southerly flow pushing moist flow into the area (NAEFS humidity, PWAT, and vapor transport plots all in excess of 90th climo percentile), with steepening lapse rates supporting Euro ensemble mean MUCAPE overnight Monday into Tuesday of 500-1250 J/kg. Should the warm frontal forcing be sufficient to kick off some thunderstorms, some strong storms overnight across the southern tier cannot be ruled out. As the low pushes through Tuesday, the cool northerlies will complicate the precipitation type forecast somewhat, though chances of freezing rain should be 15% or less, so primarily a question of rain vs snow for Tuesday. While a brief heavier shower is possible in a convective cell/around thunderstorms, rainfall totals should be manageable, with chances of 24-hour precip rates exceeding 1 inch are 10% or less.

850mb temperatures Tuesday night into Wednesday morning bottom out at around -14C, supporting some post-system lake effect snow showers, though there is enough spread in the finer details of the thermodynamic profile to have low confidence in the coverage and intensity of such snow, though the wind direction does seem likely (70+%) to be at least north of northwest, if not fully northerly to northeasterly. LES is not expected to overstay its welcome though, as high pressure well into the 1030s mb overspreads the northern Great Lakes basin by Wednesday night into Thursday. The synoptic setup is not done for the week yet - ensembles show a shortwave emerging into the Southern Plains Thursday morning that could (up to 30% chance) bring more precipitation to the region late Thursday. A much deeper trough pushing through the northern US Rockies Thursday evening could be attention-grabbing for the Friday-into- next-weekend period, which could set up another round of active weather similar to the early week system.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 722 PM EDT Sat Mar 28 2026

Mainly VFR conditions and light winds are expected through the TAF period. There is a low chance (20%) that a brief period of fog could develop around SAW between 09z-12z but widespread fog is not expected. Otherwise expect sct to bkn mid to high level cloudiness through Sunday.

MARINE

Issued at 220 PM EDT Sat Mar 28 2026

With the exception of a weak low level jet over eastern Lake Superior causing a brief period of 20-25 kt southerlies, this weekend will be quiet over the lake. Monday afternoon, northeasterlies over the west half of the lake increase to around 25 kt in response to an approaching low pressure system expected to pass through the Great Lakes region Monday night and Tuesday. Monday night, these gusts spread to the east half, increasing to near 30 kt. As winds become northerly to northwesterly behind the low Tuesday evening, a few gale force gusts to around 35 kt are possible (40-60%). With high pressure building back in Wednesday, winds quickly fall below 20 kt by noon. If the gales do occur, they will be capable of driving waves up to 10+ ft over the east half of Lake Superior and the cool northerly air blowing in will result in moderate to heavy freezing spray. Quiet weather is short-lived Wednesday night as Thursday a minor disturbance will bring wind gusts to near 25 kt ahead of the next potential large disturbance Friday into the weekend, with chances of gales up to 25%.

MQT WATCHES/WARNINGS/ADVISORIES

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