textproduct: Marquette

KEY MESSAGES

- Scattered rain showers are possible (20-60%) this morning along the southern tier.

- Seasonably warm weather will persist through Labor Day Weekend, with high temperatures expected to be in the mid to upper 70s.

DISCUSSION

Issued at 312 AM EDT Wed Sep 2 2026

This morning's 06Z RAP surface analysis shows the center of the Ontario low sitting at 1006 mb, just west of James Bay. Meanwhile, a positively-tilted surface trough is draped from the Minnesota River Valley toward the Nebraska Sandhills while ridging builds in to the Upper Great Lakes between the aforementioned two features. Per WPC analysis, an occluded front attached to the Ontario low lies across the eastern UP from approximately from Grand Marais toward Door County, WI. Those behind it have some relief from Tuesday's warm muggy conditions, with temperatures in the 50s and 60s and dewpoints depressions ranging from 1-7 degrees. In Schoolcraft, Delta, and Luce counties, however, temperatures tend to be in the high 60s to 70s with dewpoint depressions from 0-4 degrees; the Newberry METAR is currently reporting thick fog.

The main story for today are the scattered showers which will make their way across the southern part of the UP this morning. As the Plains trough progresses east with zonal flow along with continued Pacific moisture, PWAT increases to 1-1.25" for most of the UP and to 1.5" in Menominee County. Most of this moisture, however, is above 700 mb; what precipitation falls out from the relatively weak forcing will have to survive through a stout dry layer to reach the surface. Thus, anticipated QPF resides generally below a wetting rain (0.10"), except for southern portions of Menominee County which may see slightly higher accumulations. High temperatures today should land in the high 70s to low 80s, which, although cooler than yesterday, is still 5-10F above climate normal. Given NW'ly surface flow, areas with onshore flow from Lake Superior may see lower high temperatures.

Much of the remainder of the week will be dominated by upper level ridging over the central CONUS and broad troughing over eastern Canada, leaving the Upper Great Lakes in a fairly benign northwest flow pattern between the two features. The influence of the ridge will be enough to keep temperatures above seasonal norms across the the UP through the period, with daytime highs staying in the mid to upper 70s and overnight lows generally in the mid to upper 50s through the weekend. Do not see any significant rainfall in the forecast beyond Wednesday, but a few disturbances embedded in the flow will at least keep some periodic shower chances around from Thursday into the weekend.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 732 AM EDT Wed Sep 2 2026

VFR conditions with light winds rule the TAF period today at all three sites. With the bulk of today's light precip either remaining well south of CMX and already past IWD, included mention of VCSH at only SAW for a few hours this morning. LAMP probabilities are indicating a low (~15%) chance of LIFR ceilings at SAW overnight tonight, but did not include in the TAF at this time due to dry low- level air moving into place.

MARINE

Issued at 1022 AM EDT Wed Sep 2 2026

Lake Superior: Winds generally remain under 15 kts through Thursday as a low departs to the northeast. High pressure builds over Ontario and troughing deepens over the Northern Plains, resulting in a tighter pressure gradient over the west half of the lake. This yields periods of east to northeast winds of 15-25 kts late Thursday through Friday over the western waters. Stronger high pressure overhead keeps winds light (20 kts or less) lakewide through the weekend, then 20-30 kt winds return next week with a more prominent system lifting to the northeast of Lake Superior.

Northern Green Bay and northwestern Lake Michigan: Winds generally remain 15 kts or lower through this weekend as high pressure slowly builds overhead. A more prominent system lifting northeast over Manitoba and northwest Ontario early next week increases winds to around 15 kts with gusts up to 20-25 kts.

MQT WATCHES/WARNINGS/ADVISORIES

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