textproduct: Marquette

KEY MESSAGES

- An approaching system brings widespread rain, including a few thunderstorms, tonight 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 on Saturday, then rising into the 50s for Sunday and Monday.

- Another system will bring potential for accumulating snow to the U.P. mid next week, but forecast confidence is low at this time.

DISCUSSION

Issued at 335 PM EST Fri Mar 6 2026

GOES water vapor imagery reveals a subtle upper level disturbance embedded in southwest flow aloft tracking over Upper Michigan this afternoon, resulting in light rain spreading into the UP as surface temperatures reside in the upper 30s to 40s across the area. Expect rainfall amounts to remain light (mainly on the order of a tenth of an inch or less) and favor the central and eastern UP through early this evening as this weaker wave moves through. Looking upstream, a deep trough extends from the northern Rockies down through the Four Corners region with an attendant surface low analyzed near the KS/NE border. This feature is poised to bring a heavier round of precipitation to the UP tonight into early Saturday as it races northeastward with a potent shortwave trough ejecting out of the Colorado Front Range. The best thunder chances will remain south of the UP over Wisconsin and Lower Michigan within the warm sector of this system, however models continue to depict mid level lapse rates around 7.5 C/km and 100-400 J/kg MUCAPE which should be sufficient for a few rumbles of thunder across the UP overnight. The best chances for a stronger thunderstorm will be over the south-central UP where MUCAPE may reach the 400-700 J/kg range. As such, SPC continues to include the southern half of Menominee County in the marginal risk for severe thunderstorms, with large hail as the primary threat. In addition to rain and thunderstorms, patchy and locally dense fog also persists this afternoon and will likely expand in coverage again tonight given the warm and moist air mass in place atop the existing snowpack.

Another final shot of precipitation will move through on Saturday morning as a cold front sweeps across the UP from west to east. This will change rain over to light snow across the west during the morning, possibly preceded by a brief period of light freezing rain as a warm layer persists aloft before the entire column ultimately cools below freezing. Generally expect no more than a glaze of ice and 1-2 inches of snow along the Keweenaw and Porcupine Mountains before precipitation comes to an end by early Saturday afternoon. Lingering precipitation will also change over to light snow in the east as precipitation winds down, but expect minimal snow accumulations of an inch or less across the central and eastern UP through Saturday afternoon.

In terms of precipitation amounts, model QPF values remain consistent with previous cycles and continue to depict roughly 0.50- 0.75" of rain across the UP through Saturday. Higher end amounts reflected by NBM 90th percentile guidance still top out in the 1.00- 1.25" range for most of the UP, but reach as high as 1.50" across south-central through Saturday afternoon. Precipitation amounts could show quite a bit of spatial variability, with higher end rainfall amounts largely dependent on thunderstorms which could result in localized areas of heavier rain at times. Overall, there is little change from the previous forecast as WPC's marginal threat for excessive rainfall remains south of the UP through the period. That said, we could certainly still see some issues with ponding of water and poor drainage tonight into Saturday given the amount of snow still on the ground.

Sunday and Monday continue to 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. Still keeping an eye on the next system Tuesday 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. There is still quite a bit of ensemble spread regarding strength, placement, timing of this feature, albeit with at least a general consensus keeping the track south of the UP in the vicinity of the Lower Midwest and Lower Great Lakes into Wednesday. This track would tend to favor a snowier solution for the UP - potentially with some lake enhancement given a northeasterly wind direction. NBM probabilities for at least a tenth of an inch of ice have thus dropped into the low single digits since yesterday but continue to show a around 15- 25% chance for greater than 4" of snow over parts of the UP in this time frame. Will continue to monitor in the coming days. Otherwise, expect temperatures to trend cooler with daytime highs generally near or below freezing from Tuesday through mid week.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1226 PM EST Fri Mar 6 2026

A large low pressure will lift into the Upper Great Lakes, bringing rain to all sites late afternoon and tonight. Ahead of the steady rain, abundant moisture is supporting low ceilings and visibility restrictions, particularly at KSAW which is currently LIFR. A few thunderstorms cannot be ruled out, but opted not to include thunder in this TAF at this time given that best chances continue to be positioned south and east of the TAF sites. Rain will continue overnight and then switch to snow at KCMX/KIWD Saturday morning. There is potential for a few hours of freezing rain during the p- type change and prob30 groups were added to reflect the best potential timing.

MARINE

Issued at 335 PM EST Fri Mar 6 2026

Winds remain under 20 kt through tonight ahead of the next approaching system. Low level moisture will continue to result in areas of fog over the water, potentially dense at times into Saturday 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 likely (60-90% chance) Saturday night into Sunday as the pressure gradient strengthens in response to a low pressure tracking through Ontario. Have hoisted a Gale Watch for all of Lake Superior from Saturday night into Sunday afternoon. Winds fall to 25kt Sunday night with the next chance for gales quickly returning Monday as another low pressure system tracks through Ontario. Yet another chance for gales mid next week as low pressure moves into the Lower Midwest.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... Gale Watch from late Saturday night through Sunday morning for LSZ162.

Gale Watch from late Saturday night through Sunday afternoon for LSZ242>244-263-264.

Gale Watch from late Saturday night through Sunday afternoon for LSZ245>251-265>267.

Lake Michigan... Dense Fog Advisory until 7 AM EST Saturday for LMZ248-250.