077 FXUS63 KGRR 180457 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 1157 PM EST Sat Jan 17 2026 .KEY MESSAGES... - Lake Effect Snow Showers and Slick Roads Tonight - Impactful Snow and Blowing Snow Sunday Evening Through Monday - Subzero Wind Chills Monday/Tuesday, Then More Snow Midweek && .DISCUSSION... Issued at 326 PM EST Sat Jan 17 2026 - Lake Effect Snow Showers and Slick Roads Tonight Lake effect snow showers amid WSW flow increased earlier today and are helping maintain slick road conditions particularly in Muskegon, Ottawa, and Kent counties. These snow showers are aided by upstream low-level moisture in the DGZ which is producing snow over southern Wisconsin, along with augmented lift from 925-850 mb frontogenesis, as a tongue of relatively colder 850 air is advecting through northern Illinois, Indiana, and southern Michigan. Short term guidance favors an uptick in these snow showers this evening where both the lake effect and fgen-related lift is maximized, followed by a period of more concentrated but shifting heavier snow bands overnight in proximity to a sharp surface trough now moving south from northern Lake Michigan toward western Lower Michigan. As such, expecting an additional 2 to locally 5 inches over most areas west of US-131 through daybreak Sunday, along with continued slick roads. - Impactful Snow and Blowing Snow Sunday Evening Through Monday Snow intensity midday Sunday should be a little subdued prior to the arrival of the next Clipper-style low during the evening. Between about 4 pm and 10 pm Sun, southwest wind lake effect mostly within the DGZ and midlevel snow production above the DGZ will ramp up, followed by lake effect continuing as strengthening winds become more west then northwest with Arctic air on Monday. Upstream 850 mb air is favored to be around -20 to -23 C on Monday with lake induced convection climbing above 10 kft. Temperatures in the teens, powdery snow, and winds gusting 30-35 mph on Monday will create blowing snow and travel difficulty not just within the Lake Michigan adjacent counties (where snow totals should be greater) but also well inland. Amounts of 4 to 6 inches (with higher drifts) are possible near/west of US-131, and 1 to 3 are possible toward Mid Michigan. - Subzero Wind Chills Monday/Tuesday, Then More Snow Midweek Lighter lake effect snow showers continue Monday night and Tuesday. The core of coldest air will move through Monday night. Tuesday morning lows are expected to be in the single digits with wind chills -5 to -15 F. Temperatures warm up into the balmy 20s on Wednesday before dropping back into the teens Wed night and Thursday. The next clipper system and following lake effect snow during that time will be good for another few inches along with the increasingly familiar travel challenges. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1157 PM EST Sat Jan 17 2026 Variable conditions exist across the TAF sites at 05z...with IFR conditions near Lake Michigan and VFR conditions inland. MKG and GRR are down in lower ceilings and visibilities due to lake effect snow pouring off the lake in southwest flow. Inland towards LAN and JXN ceilings are VFR with no snow occurring. The thinking at this time as we will see at least MVFR ceilings spread out and affect most of if not all the TAF sites by 12z. The lake effect snow will continue to affect MKG and GRR overnight, but we may see it taper just a bit. A bit of a lull in the activity is expected during the morning on Sunday (MVFR conditions will continue to prevail due to ceilings). Sunday evening lake effect snow showers will ramp up once again with IFR conditions beginning to form once again. Southwest winds will be the dominant direction the next 24 hours with speeds often in the 10-20 knot range. && .MARINE... Issued at 326 PM EST Sat Jan 17 2026 Winds and waves hazardous for small craft persist through Sunday. West-northwest gales and heavy freezing spray are possible early Monday morning and through the day. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Winter Weather Advisory until 7 AM EST Sunday for MIZ037-038-043- 044-050-056-057-064-071. Winter Storm Watch from Sunday afternoon through Monday evening for MIZ037-043-050-056-064-071. MARINE...Small Craft Advisory until 1 AM EST Monday for LMZ844>849. Gale Watch from late Sunday night through Monday evening for LMZ844>849. Heavy Freezing Spray Watch from late Sunday night through Tuesday morning for LMZ844>849. && $$ DISCUSSION...CAS AVIATION...Duke MARINE...CAS

NWS GRR Office Area Forecast Discussion