107 FXUS63 KGRR 310441 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 1141 PM EST Tue Dec 30 2025 .KEY MESSAGES... - Accumulating Snow This Evening into Wednesday Night - Quieter for Late Week into Weekend && .DISCUSSION... Issued at 236 PM EST Tue Dec 30 2025 - Accumulating Snow This Evening into Wednesday Night Two quick hitting Canadian clipper systems move through the Great Lakes this evening into Wednesday night, each providing a bout of some accumulating snow to the region. Surface observations across MN and WI this afternoon indicate light snow is falling at many sites. While mid level WV imagery is not that impressive across the Midwest, 12z model guidance is showing a slightly more impressive steepness to the 500mb trough and associated PVA ahead of it as compared to yesterday's guidance. The combination of mid level lift, some light snow falling from the cloud deck upstream, and preexisting lake effect clouds across Lower MI will result in modest lake enhanced snow as this feature moves through tonight. 1000-700mb RH values look solid with 3-6 ubar/s of lift in the 925-850mb layer across the lakeshore tonight and stretching toward US 131. This is not major lift by any means but enough to aid in snow production. Actual lift within the DGZ is weak, so hourly snowfall rates won't be significant. 12z QPF from high resolution CAMs is suggesting 0.05"-0.15" through 12z Wednesday, but with 18:1-20:1 SLRs. This should yield 1"-3" of snow along and west of US 131 but could also stretch a bit further east potentially. A lull in lake effect snow intensity is expected Wednesday morning before picking up again midday through the afternoon. The second upper wave moves in Wednesday afternoon and as the mid level lift arrives there also looks to be better lift within the DGZ. At the surface, a cold front will be pushing through the region in the 18z Wed to 03z Thu time frame. Surface convergence along the front may provide a short burst of heavier snowfall as it pushes through. Additionally, WNW to NW wind gusts may exceed 25 mph which is enough to provide some risk for blowing snow mainly across the lakeshore but a nonzero threat exists inland as well. Model QPF near and west of US 131 is indicating another 0.10"-0.20" from 12z Wed through 12z Thu. Ratios continue to look like 20:1 via the Cobb SLR approach. Another 1"-4" looks likely for this region, impacting New Year's Eve travel. This will yield storm total snow amounts along the lakeshore of 3"-6" (isolated spots over 6") from this evening through Wednesday night and 2"-4" along US 131 (locally over 4") for grand totals. As a result, will be issuing a Winter Weather Advisory for the first two rows of counties adjacent to the lake from 21z today through 12z Thursday. East of there, grand totals of 1"-3" are expected but some adjustments to headlines may be needed (ie. possible inclusion of Osceola and Calhoun depending on trends). - Quieter for Late Week into Weekend NW flow pattern over the Great Lakes may help keep flurries and light snow showers going at times for the late week period into the weekend, though no significant accumulations are expected and areas away from the lake will likely be dry much of the time. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 1141 PM EST Tue Dec 30 2025 The first of two periods of light snow over the next 24 hours is in the process of diminishing from North to South across the terminals. It appears that the widespread snow will be south of the I-94 corridor by 06z. We will see some scattered snow showers hang on for a few hours, especially closer to the lakeshore. MVFR conditions are likely to hold. After a few hours break in the morning, light snow will quickly overspread the area between 16-19z from NW to SE. IFR is likely with the snow, with blowing snow due to wind gusts around 25 knots likely and increasing the chances of IFR. This snow will be short lived, and should be mostly gone by 00z Thu. Bands of lake effect will linger after, and migrate back closer to the lake with winds becoming more NNW. Conditions should improve with the snow and wind/blowing snow diminishing. For the GRR airport, the heaviest snow will be diminishing quickly by 1 am, leaving just some scattered snow showers with additional accumulations under an inch tonight. The next batch of light accumulating snow will begin roughly around 17-18z. Blowing and drifting will begin around the same time from around 240-250 degrees. The heaviest snow will be done then by around 21z, with snow showers lingering until 00z-01z Thu. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Winter Weather Advisory until 7 AM EST Thursday for MIZ037-038- 043-044-050-056-057-064-065-071-072. MARINE...Small Craft Advisory until 7 PM EST Wednesday for LMZ844>849. && $$ DISCUSSION...Hoving AVIATION...NJJ