textproduct: Marquette

KEY MESSAGES

- Patchy frost is possible for areas of the interior UP where temperatures fall into the mid 30s early this morning.

- Scattered showers and a few thunderstorms move west to east this afternoon through early Friday morning. Rainfall amounts will be light, generally around 0.1" or less.

DISCUSSION

Issued at 402 AM EDT Thu Aug 20 2026

Decent radiational cooling early this morning is resulting in widespread temperatures in the low to mid 40s across much of the western and central interior. And, the interior west could still dip into the mid to upper 30s by daybreak. Also, dew point depressions approaching zero across much of the forecast area could result in some quick visibility restrictions for the morning commute. Otherwise, expect the next chance for precipitation this evening through early Friday as a low amplitude shortwave within northwest flow aloft traverses the area. Showers reach the western UP this afternoon and continue into the central UP late this evening. With the dry airmass in place, latest model runs have slowed down the eastward propagation of the rain. Initially cannot rule out a rumble of thunder in the west half, but unfavorable timing for diurnal instability and weak kinematics gives low confidence on much more than a rumble. By Friday morning, CAM ensembles only point towards a 50-80% chance for amounts greater than a dime, so do not be expecting meaningful rainfall for your gardens. Isolated amounts between a dime and quarter are more likely in the western half where better saturation occurs. Another round of showers/storms along a cold front, mainly in the central UP.

Mostly dry through the rest of weekend with a chance of showers/marginal thunderstorms Saturday afternoon, though the main story will be marine hazards and gusty northerly winds Saturday/Sunday as a pair of sharp shortwaves dive south-southeast from the Hudson Bay down into the Lower Great Lakes. Modest pressure rises coupled with cold air advection (850 mb temps between 3-6C Sunday) will create northerly gusts 20-30 kts with a 40% chance of gales to 35 kts.

Model discrepancies follow into next week, though the first half looks mostly dry at this time.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 214 PM EDT Thu Aug 20 2026

Mostly VFR conditions are expected during the 18Z TAF period, but the dry airmass in place eventually gives way to -SHRA and potentially (20-40% chance) a few -TSRA (highest chance at IWD). Precip arrives at IWD and CMX first late this afternoon, continuing into the early overnight hours. -SHRA arrives at SAW tonight, holding on and off into Friday morning before dry weather returns. The exception to VFR conditions arrives behind the cold front early Friday morning when cigs lower to IFR at IWD and possibly MVFR at CMX (30-50% chance).

Otherwise southerly winds generally hold around 5 to 10 kts through the period, becoming northwest behind the cold front Friday morning. Slight deviations to that are where lake breeze influences yield an east wind at CMX in the next 1 to 2 hours and some variable conditions at SAW this afternoon.

MARINE

Issued at 226 PM EDT Wed Aug 19 2026

Lake Superior - Light winds 15 kts or below remain through Thursday morning. Southerly winds increase 15-20 kts in the eastern lake Thursday evening before falling back below 15 kts Friday. The main marine hazards return Saturday and Sunday as a pair of systems bring modest pressure rises and cold air advection over the Lake resulting in gusty N to NW winds upwards of 20-30 kts beginning Saturday morning through Sunday night. At this time, there is a low chance (20-40%) for a few gales to 35 kts mainly between Marquette and Whitefish Point.

Northern Bay of Green Bay and northern Lake Michigan - Breezy southerlies upwards of 15-20 kts increase tomorrow morning and linger through Friday as low pressure traverses the area. This results in waves building between 1-3 ft (greatest in the open waters closer to Lake Michigan). A brief reprieve in winds comes Friday night behind a weak cold front, however, two systems then dive into the area Saturday and Sunday, resulting in gusty north to northwest winds 15- 25 kts through at least early Monday.

MQT WATCHES/WARNINGS/ADVISORIES

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