Mass City, MI 49948 Weather

Key messages

- Mainly dry weather continues through the weekend. Highs in the 50s today, warming into the low 60s on Sunday and Monday (15-20F above average).

- Precipitation chances continue to increase for early next week. Confidence is increasing for widespread rainfall late Monday into Wednesday, with a 40-80% chance for 1" or more of rainfall in a 48 hour period.

Discussion

Issued at 1241 AM EDT Sat Oct 31 2026

Ridging becomes maximized at around 1030mb this morning as mostly clear skies have allowed temperatures to plummet into the 20s across the interior areas before dawn. As the ridging gives way to weak shortwave troughing today and tonight, expect cloud cover to build from the southwest this afternoon and evening as subtle WAA continues overhead. Thus, we can expect high temperatures to be a couple of degrees warmer today when compared to yesterday, getting into the 50s area-wide by this afternoon. While there is modest lift in the lower levels of the atmosphere with the shortwave passing through tonight into Sunday morning, with subsidence in the mid to upper levels, any rainfall we could see will be light (less than a tenth of an inch); as of the current forecast, rain chances across Upper Michigan range from 20 to 40%. Dry weather and warmer conditions are in store the rest of the day Sunday into Monday as ridging once again builds back into the area, with highs increasing into the lower 60s over the interior areas via strengthening WAA.

More active weather returns late Monday as a Colorado low becomes vertcially-stacked over the Plains before lifting into northern Ontario Monday night into Tuesday (or later, if at all, depending on the model solution). As this occurs, the warm front of the low looks to bring rainfall back over the area near the Wisconsin border late in the day on Monday before overspreading the rest of the U.P. Monday night. With some of the guidance (such as the Euro and Canadian suites) slowing down the progression of the low and pushing the track closer to the area (further south and east than 24 hours ago), we could see additional rainfall occur through the mid-week before the cold front of the low pushes through; with the differing suites diverging on the timing of the cold front, confidence has decreased a little on when the cold front will move through Upper MI; the earliest appears to be Tuesday and Tuesday night following the GFS suite, whereas the slowest are the Canadian and European suites which bring the cold front through Wednesday and Wednesday night. Regardless, the latest NBM brings a 40 to 80% chance of up to an inch of rainfall across the area between Monday evening and Wednesday morning, with the highest chances in the south and west.

Depending on how the low tracks, we may see lake effect precipitation behind it or dry conditions to end next week. Should the low take a more southerly route and end up closer to the U.P., we could see additional wrap-around/lake effect rain showers over the north to northwest wind belts; there could even be a mix over to snow over the far west near the end of the week if the latest deterministic Euro is to be believed. That being said, if the track of the low is more to the north and west (like it was yesterday morning and the current GFS solution), then I'd expect conditions to remain dry and for lake effect precipitation to miss our area. Currently, leaning more towards the former option as the Great Lakes will act as a source of latent heat release, allowing for localized troughing to develop overhead and thus increasing chances of trending the track of the low closer to the Upper Great Lakes. Regardless, expect the temperatures to remain well above normal for early November as highs in the lower 60s are expected Monday and Tuesday and the 50s Wednesday and Thursday; the NBM has the lows generally in the 40s throughout much of next week.

Aviation

Issued at 736 AM EDT Sat Oct 31 2026

VFR conditions will prevail through at least early evening. However, an approaching disturbance will lower ceilings to MVFR levels after Sun 00Z at both IWD and SAW, followed by CMX closer to Sun 06Z. Further deterioration to IFR/LIFR at CMX and SAW after Sun 06Z will be highlighted with PROB30s for now. Meanwhile, expect light and variable winds at all sites through sunrise when southerly winds of 5-10 kt become predominant.

Marine

Issued at 1241 AM EDT Sat Oct 31 2026

Lake Superior: Light winds of 20 kts or less continue through this weekend into early next week as high pressure ridging today only gets interrupted by a weak lower atmospheric shortwave tonight into Sunday morning before returning early next week. The calmer conditions continue until Monday night into Tuesday, when a warm front moving in from the south brings southeasterly winds of 20 to 25 kts back over the eastern half of the lake. While we could see southerly winds gust up to 30 kts by Tuesday night (highest over the eastern open lake), expect winds to remain elevated at 20 to 25 kts behind the cold front as the wind direction turns northwesterly behind it for the middle of next week.

Northern Lake Michigan and northern Bay of Green Bay: Light winds of 15 kts or less continue today until late Monday as high pressure ridging generally remains overhead (save the weak shortwave moving through the Upper Great Lakes tonight into Sunday morning). As a warm front moves into the area late Monday, expect the winds to increase from the south and southeast, increasing to 15 to 25 kts late Monday night into Tuesday; some gusts up to 30 kts will be possible between Washington Island and Garden Peninsula on Tuesday. Expect the winds to weaken slightly behind the warm front into the middle of the week, before picking up from the west and eventually northwest to around 15 kts by no later than next Thursday.

Watches, warnings and advisories

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