textproduct: Marquette

KEY MESSAGES

- There is up to a 50% chance for rain showers tonight over the southern half of the U.P. Lake effect rain showers will become widespread through Wednesday and transition to snow Wednesday night.

- An extended period of lake effect snow is expected for Wednesday night into Saturday. The most impactful periods look to be during the overnight hours, especially Thursday night. 3-6" of snowfall is expected for the Wednesday Night through Friday period over the higher terrain of Marquette and Alger Counties with 1-3" elsewhere (expect less close to Lake Superior, Menominee County and the Eastern U.P.).

- Temperatures rebound to unseasonably warm 50s early next week.

DISCUSSION

Issued at 320 PM EST Tue Nov 10 2026

Early afternoon GOES-East Day Cloud Phase RGB imagery shows tranquil weather with only some fair weather cu over the eastern UP. Upper air pattern consists of primarily northwesterly flow over the north- central CONUS as split flow at the US/Canada border at the Rockies is leading to high surface pressure upstream but with low pressure developing in the central to northern Plains. Elsewhere, a deep closed low continues to gyrate over Quebec with several embedded shortwaves. For today, the high pressure will lead to this being the last well above normal day (highs in the 50s are ~10 degrees above normal) until next week as cooler weather comes in for the later half of the week and into the weekend.

Tonight, the aforementioned low pressure will track south of the area bringing increasing cloudiness to the area. An area of rain will accompany this low on the north side in an area of moderate fgen providing forcing coinciding with deeper moisture. Models diverge on the exact placement of this feature but felt confident enough to bring PoPs up over the southern half of the U.P. late tonight into Wednesday morning. NBM was running cold for tonight with temperatures below freezing over the interior. Given the increasing cloud cover and rain chances, opted to blend in some raw (non-bias corrected) guidance to keep lows Wednesday morning above freezing.

While the southern branch of the upstream shortwave (and its associated surface low) head south of the region, the Quebec closed low aloft retrogrades, resulting in a series of shortwaves passing over the area and Wednesday through Friday. This will bring a sustained period of cold advection to the area with 850mb temps falling into the -8 to -10C range, starting Wednesday afternoon. Expect temperatures to start out in the 40s for the first half of the day but as a cold front pushes south and northerly flow develops, temperatures fall through the afternoon hours. Widespread lake effect rain showers are expected to develop on Wednesday afternoon over the northern part of the U.P. in response to the cooler temperatures over a Lake Superior that is still around 8-10 C. As temperatures cool through the evening expect snow to mix in over the higher terrain with a changeover to snow elsewhere as the night progresses. As the low aloft wobbles over eastern North America, continued cold air aloft and additional embedded shortwaves keep LES in the forecast through Saturday morning with daytime temperatures (highs in the 30s) falling to near or slightly below average.

Several forecast challenges present themselves with this event and did quite a bit of deviation from the NBM (blended guidance) in the forecast package. NBM is struggling to handle the pattern change with daytime temperatures too warm and overnight lows too cold (trained on cool, clear nights). Warmed temperatures up quite a bit for Wednesday and Thursday night. NBM was indicating lows in the low to mid 20s over the interior with subfreezing temperatures to the Lake Superior shoreline. This seems unlikely given 850mb temps are only -8 to -10 and the lake temperatures are 8-10C. Additionally, widespread cloudiness and precipitation will limit cooling. Brought lows up to around 34 near the lakeshore and low 30s over the eastern U.P., with upper 20s across the west for Wednesday night. Similar adjustments may be necessary for Thursday night and lows beyond then given continued onshore flow and previously mentioned factors. As far as intensity and accumulations, the NBM continues to struggle with QPF, so blended in other guidance (probability matched mean guidance, other blends, etc) to bring up QPF amounts. Convergent flow favors at least a few more dominant bands setting up over the eastern half of Lake Superior with another band over the central part downwind of Lake Nipigon which should moisten the atmosphere. Models have come into better agreement with the depth of moisture with most indicating at least some of the DGZ is intersected along with inversion heights up to 8kft (possibly higher over the relatively warm waters of Lake Superior). Thus moderate snowfall rates (0.5"-1"/hr) seem likely in the more dominant bands with the potential for brief heavy snow bursts (1+"/hr) over the higher terrain of the north-central and possibly Keweenaw. Marginally cold low levels and warm ground temperatures will probably keep snow ratios on the lower side but still expecting several inches of snowfall over the higher terrain (Keweenaw, Marquette County and Baraga County) Wednesday night through Friday, with the most impactful period being during the overnight hours with some improvement during the daytime as temperatures warm close to or slightly above freezing. Near the lakeshore and over the eastern U.P. temperatures will likely remain above freezing but wouldn't be surprised to see accumulations in the grassy areas at times with enough wet-bulb effects in the more intense bands. Confidence has not increased enough to issue an advisory and totals/rates will be too low for any Winter Storm headlines, but this is still worthy of enhanced messaging given it will be the first widespread snow event of the season. As typical with LES the guidance is also spread on the location of the more dominant bands but an overall forecast of 3- 6" over 48 hours seems reasonable for the aforementioned high terrain areas with 1-3" elsewhere, away from the shoreline. Bands may manage to travel well inland, to the MI/WI border as theta-e lapse rates look to become conditionally unstable over much of the area, even during the overnight hours Wednesday night into Friday morning.

LES should wind down Saturday, confined mainly to northern Marquette County and Alger County during the morning hours with a few lingering rain/snow showers into the afternoon, though as is typical with LES events, wouldn't be surprised if LE showers linger longer than guidance suggests. As ridging aloft moves over the Plains, high pressure will keep Sunday through Tuesday mostly dry with temperatures warming into the 40s and eventually back into the upper 40s to lower 50s.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 626 PM EST Tue Nov 10 2026

VFR conditions hold through the night at all sites before deteriorating to at least MVFR CIGs & VIS after ~12Z tomorrow. All sites see VCSH into the pre dawn hours Wednesday, followed by - SHRA/BR into the morning as precipitation becomes more widespread. Guidance for both CIGs and VIS indicates a low chance (20-30%) for IFR and IWD and CMX into Wednesday afternoon, and better chances (30- 50%) for IFR at SAW as winds shifting northerly bring in more persistent lake effect/enhanced rain to SAW. A few snowflakes may eventually mix in with rain showers later in the day Wednesday, but best chances for snow hold off until after 00Z.

MARINE

Issued at 320 PM EST Tue Nov 10 2026

High pressure will bring winds below 20 kt this afternoon and waves below 4 ft tonight. Wednesday, a cold front brings gusty north winds to around 25 knots (chances of gales 20% or less) with additional minor disturbances aloft keeping gusty winds in the eastern half of Lake Superior through Friday evening. This will drive waves of up to 4 ft on Lake Michigan and 4-7 ft on Lake Superior by Thursday morning. Waves fall below 4 ft Friday afternoon for all except the east half of the lake, with waves falling below 4 ft in the east Saturday morning. High pressure will keep winds below 20 kt and waves mostly 2 ft or less through the first half of next week.

MQT WATCHES/WARNINGS/ADVISORIES

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