textproduct: Marquette

KEY MESSAGES

- Gusty easterly to southeasterly winds may lead to choppy waters and rip currents, particularly across eastern Lake Superior and northern Lake Michigan through this evening.

- Spotty, light rain showers continue over the eastern half of the UP this afternoon, then another batch of light rain showers slowly moves west-to-east through the UP this evening through early Sunday.

- A warming trend in the forecast may cause increased heat risk for vulnerable/sensitive populations as well as summer-like afternoon thunderstorms for the first half of next week, though uncertainty remains high.

DISCUSSION

Issued at 253 PM EDT Sat May 23 2026

Afternoon RAP analysis features broad midlevel troughing over the Plains, and an embedded shortwave over MN as well as another heading into the Lower Great Lakes. At the surface, this places the UP in between two weak surface lows, one over northern MN and another over northern OH. Resulting weak isentropic ascent north of the Ohio low has allowed for spotty, light rain shower activity throughout the central and eastern UP. The western UP, meanwhile, has largely stayed dry so far as bands of rain showers have remained generally offshore while the low moves northward towards Manitoba. Under otherwise cloudy skies, temperatures are rising into the lower to mid 60s for most, apart from where south/southeast winds are onshore of the Great Lakes. There, temperatures are struggling to break out of the 50s.

Meanwhile, southeast winds remain elevated this afternoon in between these two systems, with gusts up to 20-30mph particularly over the eastern UP, eastern Lake Superior, and northern Lake Michigan. This continues to lead to a potential for choppy waters as well as rip currents along the beaches of the Great Lakes. A Beach Hazards Statement remains in effect for the beaches of Schoolcraft county through this evening. Winds finally fall back below 20mph after midnight.

Into tonight, the parent trough over the Northern Plains begins to dig into the Great Lakes while the shortwave over MN becomes embedded int the broader flow. As this happens, the batch of showers over western Lake Superior finally slowly make their way eastward through the UP, weakening as they do. These could drop light rain totals up to a tenth of an inch over some spots in the western half of the area, but only trace amounts at most are expected in the eastern UP while showers wrap up there closer to sunrise. Mainly dry weather follows for the remainder of the day Sunday as weak ridging attempts to recover. Otherwise, expect temperatures to fall back into the 40s tonight, then climb much higher on Sunday as skies clear out. Expect highs in the 70s for most.

The warming trend continues into Monday and Tuesday, with 850mb temperatures climbing to around 12-14C Monday and even higher up to 14-16C Tuesday. This allows for highs in the 80s for most both days, with some spots making a run for the 90 degree mark in the interior- western and south-central UP Tuesday afternoon. This could prove hazardous to heat-sensitive populations. Meanwhile, chances for thunderstorms will be present both Monday and Tuesday afternoon, courtesy of the good old-fashioned diurnal instability as well as a subtle shortwave moving through Monday to boost coverage. CAPE potentially increases above 1000j/kg each day, though shear is negligible. This points to a potential for some stronger, if short- lived convection each afternoon, should storms fire at all. Will note that model soundings also remain quite dry.

Temperatures gradually trend downward Wednesday onwards as a closed low over Quebec retrogrades some, sending cooler air into the Great Lakes. Away off to the western CONUS, another closed low will be spinning...somewhere over the Sierras or even as far eastward as the Four Corners. In between, broad ridging builds over the Plains into the Great Lakes. This should help us stay generally dry through the latter half of next week.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 743 PM EDT Sat May 23 2026

Upstream troughing continues weak rain showers over the UP into Sunday and yields deteriorating flight conditions tonight at all sites. Worst conditions are expected at CMX and SAW where cigs drop to LIFR. Expect light and variable winds tonight to shift westerly 5- 10 kt by the end of the period as an occluded front pushes through, vis lifts, and skies scatter out for Sun afternoon.

MARINE

Issued at 253 PM EDT Sat May 23 2026

Winds mainly out of the southeast over the eastern half of the lake remain elevated through the rest of the afternoon and evening, with gusts to 20-25kts becoming common. Closer to the international boundary, some higher gusts to 30kts are possible. Conditions are calmer over the western arm of the lake, where northeast winds are coming in below 20kts. Winds fall off tonight, and likely remain below 20 kts through much of next week as high pressure returns to the Great Lakes.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Beach Hazards Statement until 10 PM EDT this evening for MIZ014.

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