textproduct: Marquette

KEY MESSAGES

- Areas of dense fog, drizzle, and freezing drizzle developing tonight into early Friday morning may lead to low visibility, slick spots on roadways, and hazardous travel.

- An approaching system brings widespread rain, including a few thunderstorms, this afternoon into Saturday. Rain changes to light snow across the west half early Saturday.

- Temperatures continue to come in above average through early next week. Highs will be in the upper 30s to 40s through Saturday, then rising into the 50s for Sunday and Monday.

DISCUSSION

Issued at 223 AM EST Fri Mar 6 2026

Early morning RAP analysis features features deep troughing anchored over the Four Corners, with a surface low over western Kansas. Meanwhile, steep surface high pressure is centered over New Brunswick. In between, the Great Lakes are under southerly flow that is funneling warmer air into the region. With ample lower-level moisture owing to our melting snowpack, fog and low stratus are abundant among surface observations and satellite. Light radar returns are also apparent over the UP and Lake Superior, likely owing to our weak ascent. What is actually falling? Surface temperatures hover in the lower to mid 30s, and should hold steady or slowly rise the rest of the night, but while we are not lacking for lower-level moisture, midlevels are still rather dry. This would point to more of a drizzle or freezing drizzle compared to honest-to- goodness rain/snow showers. Have opted for a mixed bag, given the occasional heavier (near 30dbz) echoes. Little by way of any impacts are expected apart from the odd slick spot on roadways. Meanwhile, areas of fog could lead to rapid reductions in visiblity at times; have held off on headlines so far as sites area-wide are well above a mile, but will continue to monitor given that WI and MN have plenty of spots falling as low as a quarter mile.

As we head into the daytime hours, split flow develops over the western CONUS and a potent shortwave embedded in the large-scale trough ejects out of the Colorado front range towards Upper Michigan. An initial, more subtle wave rippling through kicks off a first batch of rain showers during the afternoon; simulated reflectivity courtesy of the CAMs favors the south-central and eastern UP for this initial round, with more spotty precipitation over the western half of the UP. Shower activity tapers into the early evening, then widespread rain spreads into the UP mainly from midnight onwards as the main wave tracks in. The bulk of the thunderstorm activity associated with this system is expected to remain south of the UP in the warm sector across Wisconsin and Lower Michigan, however mid level lapse rates around 7.5 C/km and 100-400 J/kg MUCAPE should be sufficient to support a few rumbles of thunder across the UP as this next batch moves through, especially south- central. While confidence in severe storms remains low, will note that SPC highlights the south-central UP in a Marginal (Category 1) risk for severe storms, with hail the primary threat.

Finally, into Saturday morning, yet another batch of precipitation moves through with the passing cold front. By then, model soundings in the western UP look cool enough for a change over to snow (though some icing is not out of the question given the warm nose aloft). A quick 1-2in of snow is possible in the western UP. Any lingering precipitation in the eastern UP Saturday afternoon should change over to snow.

Precipitation amounts remain one of the primary questions from Friday into Saturday, and guidance/forecast thinking has not changed much from previous cycles in that regard. The most likely scenario still calls for roughly 0.50-0.75" of rain across the UP, with high end amounts reflected by NBM 90th percentile values still getting into the 1.00-1.50" range by Saturday afternoon. Precipitation amounts could show quite a bit of spatial variability as the presence of thunderstorms could result in localized areas of heavier rain at times. Overall, WPC's marginal threat for excessive rainfall remains south of the UP through this period, but we could certainly still see some issues with ponding of water and poor drainage given the amount of snow still on the ground.

Sunday and Monday look warm and mostly dry within zonal flow as a pair of lows pass well to the north across Ontario. Look for daytime highs to climb into the 50s in many locations as overnight lows stay above freezing area-wide Sunday night. The next system of interest looks to impact the region next Tuesday night into Wednesday as another wave ejects out of the South Plains and potentially phases with a northern stream trough during the middle of next week. Ensemble guidance displays a high degree of uncertainty regarding strength, placement, timing of this feature, leading to a low confidence in precipitation type and amounts. Still, they seem to be favoring a track that takes it somewhere over the Lower Midwest and near/over the Lower Great Lakes into Wednesday. This track would be more favorable for snow - potentially with some lake enhancement given a northeasterly wind direction. NBM probabilities show a around 15-25% chance for greater than 4" of snow or greater than a tenth of an inch of ice, respectively, over parts of the UP in this time frame. Will continue to monitor in the coming days. Otherwise, expect temperatures to trend cooler Tuesday onwards.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1224 AM EST Fri Mar 6 2026

Abundant moisture near the surface tonight will lead to periods of low stratus (LIFR to airport minimums possible) or FG at all sites through the morning hours. Models have trended towards keeping IWD in low ceilings throughout this TAF period with the solution of southerly winds causing a relief into VFR/MVFR now an outlier. CMX similarly will remain IFR or lower throughout the period with upslope flow off Lake Superior from multiple directions throughout the period. SAW will see a gradual descent from the current MVFR to IFR and then LIFR, where chances of remaining in LIFR throughout the period continue to increased with newer and newer model runs. In the afternoon hours, rainfall approaches from a disturbance that will bring 20-40% chances of TSRA to SAW and IWD after 00Z.

MARINE

Issued at 223 AM EST Fri Mar 6 2026

Winds shifting out of the southeast over the eastern half of the lake continue to gust to near 20kts, while winds remain more light and variable to the west. Low level moisture will continue to result in areas of fog over the water, potentially dense at times into Friday morning. Winds shift northwesterly on Saturday with a few gales to 35 kt possible over the eastern half of the lake. Widespread southwesterly gales are possible (50-75% chance) on Saturday night into Sunday as the pressure gradient strengthens in response to a low pressure tracking through Ontario. Wind fall to 25kt Sunday night with the next chance for gales quickly returning Monday as another low pressure system tracks through Ontario. Chances for gales return midweek next week as low pressure moves into the Lower Midwest.

MQT WATCHES/WARNINGS/ADVISORIES

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