textproduct: Marquette

KEY MESSAGES

- A Clipper system brings widespread rain showers and a few rumbles of thunder today with light rain showers lingering into Wednesday morning.

- Gales are possible over central Lake Superior Tuesday and again on Wednesday.

- Warmer than normal temperatures are favored by the end of this week. In addition, a more active pattern is expected as we head towards the latter half of May.

DISCUSSION

Issued at 256 AM EDT Tue May 12 2026

Early this morning model height analysis and water vapor imagery showed a shortwave trough moving through Manitoba with a sfc trough extending south through the Dakotas. Showers and thunderstorms had developed along the warm front from southern MN through NW WI and into Northern MN in an area of waa and elevated instability. Clouds were spreading across the western and central U.P along with increasing southeasterly winds. This was helping to steady temperatures with warming in the western U.P, it was 52F in Ironwood at 2am. Over the east it was chilly with temperatures in the 20s and 30s as skies remained clear.

Low pressure will track from MN this morning to northern Lake Michigan by late this evening. Expect widespread showers to accompany a warm front as it pushes east across the U.P. Elevated instability will be enough for a few rumbles of thunder as well. The central and western U.P. will see a break from widespread showers by early afternoon but additional showers and a few thunderstorms will develop by late afternoon as the low pushes across the southern U.P. As the low pressure pushes east overnight cold air advection will bring cooler air back into the region along with lake enhanced rain showers and breezy northerly winds. Snow will mix in with the rain late tonight into Wednesday morning over the higher elevations of Marquette and Baraga counties but little in the way of accumulation is expected. Overall rainfall amounts will be in the 0.25-0.50" range though areas of the far northern and eastern U.P. could exceed a half inch, 50-70% chance.

For the remainder of Wednesday and for most of Thursday, ridging builds in and winds go light over land; expect a clear-sky day with high temperatures closer to climate normal (mostly low 60's, but reaching into the low 70's in the interior west) on Thursday. These conditions will be short-lived as a second clipper passes just north of Lake Superior from Manitoba on its way to Quebec between midday Friday and Sunday. This clipper's passage corresponds with warmer, moister air reaching up from the Gulf. Additional rounds of showers are anticipated over the weekend along with warmer daytime highs (widespread high 60's/low 70's) and higher RH's Friday through Sunday. Given the rounds of precip expected with these two clippers, elevated fire weather concerns should be allayed throughout the week, despite intermittent windy conditions and higher temperatures later in the week. We can look to the warmer and wetter conditions expected later in the week to ramp up the region's (thus far) delayed green-up.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 751 AM EDT Tue May 12 2026

VFR conditions will deteriorate through the day as a low pressure moves through the area. Several rounds of showers are expected and mainly highlighted with PROB30 groups as timing and impacts are less certain due to the showery nature of the precipitation. The first batch of showers will move through CMX and SAW this morning with vsby reductions to MVFR possible. Thereafter increasing low level moisture will bring conditions down to MVFR this afternoon at CMX and SAW. IWD will be in the warm sector of the system and likely maintain VFR through at least the early afternoon. Late in the afternoon and evening another round of showers, and possible a thunderstorm, develops. Conditions will fall to IFR and possibly LIFR at times as showers move over the terminals. Showers will become light late tonight but IFR cigs will remain through the end of the TAF period.

MARINE

Issued at 256 AM EDT Tue May 12 2026

A Clipper low will move through the Upper Great Lakes through Wednesday morning bringing increasing southerly winds today with gusts to gales for areas adjacent to the Keweenaw and the east-central part of the lake; a gale warning is in effect. A few thunderstorms are expected today along with widespread showers. The main threat from thunderstorms would be lightning as hail and strong thunderstorm winds look unlikely. Reinforcing cold air advection arrives behind the low late tonight into Wednesday, expect the winds to pick up from the north-northwest across the central and eastern lake. Left the existing gale watch as is, though probabilities for gales have decreased, about a 30-50% chance over the south central lake near Marquette and Munising by Wednesday morning.

As the low continues to depart eastward and high pressure ridging builds in from the west, expect the winds to dwindle with time late Wednesday into Wednesday evening, with light winds of 20 knots or less being seen across the entire lake by Wednesday night. Expect the light winds to continue through the day Thursday as the high pressure ridging passes by. However, with a warm front pushing in from the west Thursday night through Friday, expect winds to pick up from the south once again to at least 20 to 30 knots over much of the lake; gales will be possible on Friday (60-80% chance).

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... Gale Warning until 6 PM EDT this evening for LSZ244-245-248- 249-264>266.

Gale Watch from Wednesday morning through Wednesday afternoon for LSZ248>250-265-266.

Lake Michigan... None.