textproduct: Marquette

KEY MESSAGES

- Patchy dense fog is possible early this morning across the west and central UP and again tonight.

- Warmer than normal temperatures continuing through the week. Highs in the upper 30s to low 50s. Lows near or just above freezing late in the week.

- Mostly dry weather until Friday and Saturday when widespread rain chances return (60-90% chance).

DISCUSSION

Issued at 240 AM EST Wed Mar 4 2026

Early this morning satellite water vapor imagery and model height analysis continued to show broad troughing over Canada with ridging along the Pacific Coast pushing eastward ahead of shortwave troughing. Zonal upper level flow was over the northern tier of the U.S. with a stalled frontal boundary near the U.S./Canadian border and northern Lake Superior. During the late evening widespread low clouds over the northern two thirds of the U.P. dissipated, which has allowed for some fog formation as the low levels cool. Temperatures were in the upper 20s and 30s with southerly winds.

Zonal upper level flow will remain over the region today along with the cold front continuing to stretch from west to east along the U.S./Canadian border and over Lake Superior, which will waffle south and north through tonight. Meanwhile a trough will dig down the west coast and into the southwest U.S. by Thursday night. This will bring strengthening southerly flow over the area, helping to lift the cold front well north of the region on Friday as the trough shifts east and associated low pressure ejects from the Colorado Rockies. The low will track towards the Upper Great Lakes by Saturday morning with a trailing cold front and northwest winds expected to push through during the day Saturday. The flow will quickly switch southerly again on Sunday as low pressure tracks through Ontario. The upper level flow will become zonal again on Sunday, continuing into early next week.

Overall expecting another day of temperatures well above average this afternoon, highs in the 40s and near 50 along the MI/WI state line. With respect to how warm it will get today forecast confidence is low. Isentropic ascent in the low levels is expected to develop low clouds over the U.P. this morning but the extent and clearing through the day varies among guidance. The NBM mean is running on the cooler side, near the 10th percentile of the distribution. Wherever clouds are able to clear out I'd expect temperatures to overachieve, NBM 50th and 90th percentiles are as warm as the mid and upper 50s in the southern parts of the U.P. A 1038mb sfc high pressure moving through Ontario towards James Bay today will help to push the frontal boundary south through tonight, which could bring some freezing drizzle or very light snow to Isle Royale and the possibly the Keweenaw by this evening. Southerly winds will turn northeast tonight across the entire U.P. with lows in the 20s. Widespread fog is expected tonight, especially over the upslope areas. With temperatures below freezing, soundings showing saturation up to about 3kft and upslope flow wouldn't be surprised to see some freezing drizzle as well late tonight.

Low level clouds could linger on Thursday but expecting many areas to see some sunshine by the afternoon. It will be a bit cooler with easterly winds and highs in the upper 30s to low 40s central/east and mid 40s west.

Friday through Saturday the Colorado low still looks to track from the Plains to the Upper Great Lakes. Models continue to diverge on the track of the low but confidence is high that most of the precipitation will fall as rain. Models continue to show elevated instability which could be enough for heavier showers and possibly a rumble of thunder. With plenty of snow cover over the northern half of the U.P. any heavier convective showers could result in ponding of water on roadways. A cold front will sweep through as the low departs on Saturday resulting in breezy conditions and possibly snow during the moring in the western U.P., though any accumulations are expected to be less than an inch.

Continued above average temperatures are expected Sunday into early next week with highs in the 40s to near 50 and lows in the 20s. There is a slight chance for showers but widespread precipitation isn't likely during this period. A stronger storm system could impact the region during the later half of the week but quite a bit of uncertainty remains at this point. It could mark the start of a cooler pattern, the CPC outlook days 8-14 is indicating higher chances for below normal temperatures and equal chances for above/below normal precipitation.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1226 AM EST Wed Mar 4 2026

VFR ceilings to start the forecast period lower to MVFR into early Wednesday, then further to IFR at CMX and SAW after 12Z. With light winds, temperatures cooling to the dewpoint, and moist air over our snowpack, at least some patchy fog is expected into Wednesday morning. This may lead to IFR visibility especially at CMX and SAW. An improvement to VFR is looking likely at IWD into the afternoon hours, but MVFR/IFR ceilings linger at CMX and SAW through the rest of the period even though visibility restrictions begin to improve. IFR fog may return again to CMX and SAW after 00Z Thursday.

MARINE

Issued at 240 AM EST Wed Mar 4 2026

Light southerly winds will shift northeast this afternoon as a frontal boundary sags south over the lake. Low pressure deepens along the eastern slopes of the central Rockies will bring a tightening pressure gradient, helping winds strengthen to 25kt tonight into Thursday. Low pressure tracking through the Upper Great Lakes on Friday into Saturday will bring increasing southerly winds to 30kt, shifting northerly on Saturday with a few gales to 35 kt possible. Widespread southwesterly gales are possible (40-60% 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 stronger winds coming midweek as another low pressure tracks into the Great Lakes.

MQT WATCHES/WARNINGS/ADVISORIES

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