488 FXUS63 KGRR 171157 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 657 AM EST Sat Jan 17 2026 .KEY MESSAGES... - Snow Showers Especially Near/North of Muskegon Through Tonight - Impactful Period of Snow and Wind Sunday Night Through Monday - Subzero Wind Chills Monday/Tuesday, Then More Snow Coming Midweek && .DISCUSSION... Issued at 339 AM EST Sat Jan 17 2026 - Snow Showers Especially Near/North of Muskegon Through Tonight A frontal boundary draped across west central Lower MI today will move very little as abundant low level moisture and lift remain in place for additional snow shower production especially from Muskegon to the north, eventually extending further south tonight. Regional radar early this morning indicates slow moving snow showers extending from the Milwaukee metro area ENE toward Oceana and Mason Counties. The RAP13 925-850mb omegas are frequently 5-10 ubar/s north of Muskegon today and tonight along with inversion heights around 10k ft. Lift is greatest below the DGZ but it does also extend into the DGZ as well. 00z HREF 24hr QPF LPMM indicates additional 0.25" to as much as 0.50" in the heaviest snow showers through 12z Sunday from Muskegon County to the north, yielding additional accumulations of 3"-5" with a localized bullseye of 5"-8" somewhere across Oceana or Mason County (difficult to pin down exactly where). As such, have opted to extend the Advisory through 7am Sunday now for Muskegon County to the north and have dropped the remainder of the Advisory as the greatest impacts are over for now, though snow showers are still expected at times today and tonight with some additional light accumulations possible. - Impactful Period of Snow and Wind Sunday Night Through Monday An Arctic front will be arriving Sunday night into Monday bringing impactful lake-enhanced snow and blowing snow especially for areas near and west of US 131. 1000-700mb trajectories indicate SW flow lake enhancement 21z Sunday through 03z Monday then a shift toward W to NW after that. Nam12 is indicating significant lift within the DGZ as the Arctic front approaches and after it moves through, with 10-20 ubar/s shown near/west of US 131. Bufkit soundings using Nam12 at Holland indicate very deep moisture up to 20k ft Sunday evening into Monday morning with significant lift located exactly in the center of the DGZ. The heaviest snowfall rates look to occur during this time frame. Additionally, wind gusts increase to the 25-35 mph range inland with higher gusts along the lakeshore. The powdery nature of the snow will be prone to blowing and drifting. White outs are looking likely along the lakeshore with hazardous travel conditions likely extending to the US 131 corridor and potentially east as bands blow inland. Temperatures of 10F to 15F along with blowing/drifting snow will make road treatment efforts a challenge. Additional winter headlines will be needed with future forecast updates. - Subzero Wind Chills Monday/Tuesday, Then More Snow Coming Midweek A wintry pattern continues into midweek. 850mb temperatures look to bottom out right around -25C Monday into Tuesday, yielding single digits and low teens for air temps and subzero wind chills. Those wind chill readings could get as cold as -10 to -20 across the area, lowest away from the lake. Snow showers continue into Tuesday but lighter, though poor visibility is possible given the finer grain snow. Medium range ensemble guidance is favoring an additional upper trough to swing through midweek. ECE/CMC guidance is similar in strength and timing of 500mb height falls on Wednesday. The GEFS also shows it but a bit weaker. Deterministic guidance is indicating a surface low tracking through the state on Wednesday with potential lake enhancement and gusty winds. The position of this forecast low is a bit in question and as such it is tricky to pin down which areas may get the most snow. At this point there is potential for several inches of additional snow with impacts to travel across the area. Lake effect snow may take over after that with additional amounts possible into Thursday. && .AVIATION /12Z TAFS THROUGH 12Z SUNDAY/... Issued at 645 AM EST Sat Jan 17 2026 Variable conditions are likely today in and out of snow showers mainly for MKG and GRR before spreading further south toward AZO/BTL especially after 00z. IFR is most likely to occur at MKG, due to visibility reductions. Can`t rule out ceilings briefly dipping below 1000 ft at MKG and GRR. && .MARINE... Issued at 339 AM EST Sat Jan 17 2026 A Gale Watch has been issued from late Sunday night through Monday evening as an Arctic front moves through. Gusts could exceed 40 kts during this period. In addition, heavy freezing spray is a near certainty as air temperatures plunge along with the gale force winds. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Winter Weather Advisory until 7 AM EST Sunday for MIZ037-038-043- 044-050. MARINE...Small Craft Advisory until 7 PM EST Sunday for LMZ844>849. Gale Watch from late Sunday night through Monday evening for LMZ844>849. && $$ DISCUSSION...Hoving AVIATION...Hoving MARINE...Hoving

NWS GRR Office Area Forecast Discussion