198 FXUS63 KGRR 250929 CCA AFDGRR Area Forecast Discussion...CORRECTED National Weather Service Grand Rapids MI 429 AM EST Sun Jan 25 2026 .KEY MESSAGES... - Snow in Southern Michigan Today - Lake Effect Snow Showers Monday - Additional Snow Accumulation and Breezy Tuesday && .DISCUSSION... Issued at 415 AM EST Sun Jan 25 2026 Three phases of impactful snow in quick succession in the short term through Tuesday, not even counting the continuing cold with some lingering lake effect snow Wed through Fri... - Snow in Southern Michigan Today On the northern fringe of the significant multi-region winter storm, isentropic lift above 700 mb and embedded transient fgen bands near the top of a deep saturated DGZ will produce light to briefly moderate snow mostly south of Holland, Grand Rapids, and Alma. Good model agreement for 1 to 3 inches in the vicinity of a St Joseph to Lansing line, and 3 to 5 inches southeast of Battle Creek-Mason. NBM probabilities give southeast Jackson county about a 60-70 percent chance of 6 inch totals assuming 17:1 ratio, and the mean of the HREF also approaches 6 inches in southeast Jackson. Greatest opportunity for over a half-inch per hour snowfall rates in south-central MI will be from about mid day to late afternoon, and the majority of the snow is likely to have fallen by 7 PM. Temperatures will remain cold with highs in the mid teens. - Lake Effect Snow Showers Monday As north winds become increasingly northwest tonight, the mid- lake convergence band of lake effect snow may be very near the shoreline of Mason and Oceana counties after 7 PM this evening. A band of relatively heavy snow showers is likely down much of the lakeshore by daybreak Monday, given sustained surface convergence with stronger winds over the lake and lighter winds over Lower Michigan. The snow showers will spread inland and weaken by afternoon. HREF mean snow suggests another advisory will need to be considered for western Allegan and Van Buren, plus western Mason and Oceana counties, for Monday morning with 3 to locally 6 inches possible. Local snowfall rates there could exceed an inch per hour with moist convection off the lake ascending through a saturated DGZ in the low levels. - Additional Snow Accumulation and Breezy Tuesday Clipper system with a surface low tracking through Lk Superior to northern Lk Huron will swing through Tue morning. Ironically, the "warm" advection side of it occurring Mon night may warrant cold weather advisories southeast of Grand Rapids, with temperatures near zero and breezy southwest winds bringing wind chill down to around 15 below overnight. Lake enhanced snow totaling 1 to 3 inches appears favored near/west of US-131, after midnight Monday night through afternoon Tue. Winds gusting around 25 mph with temperatures staying below 20 degrees may result in areas of blowing/drifting on Tue. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1158 PM EST Sat Jan 24 2026 IFR cigs have begun to infiltrate some TAF sites, GRR and AZO. Winds have shifted to the Northeast. MVFR has spread to JXN and BTL. Conditions will continue to deteriorate between 06Z and 09Z as the weather system continues to pass through Indiana and Ohio. The worst of the showers will be after 12Z with IFR to LIFR cigs and vsbys at the southern TAF sites continuing until around 00Z. Conditions will then slowly improve as the system moves eastward. VFR should develop between 00Z to 06Z Monday. && .HYDROLOGY... Issued at 347 PM EST Sat Jan 24 2026 Bitterly cold temperatures will continue to increase the ice forming on our rivers. An ice jam has developed along the Muskegon River near Bridgeton and Newaygo as of Saturday Afternoon. Observations suggest the ice jam is beginning to stabilize but water fluctuations may continue for at least the next 6-12 hours. The ongoing flood advisory has been extended until Sunday Evening across this area. Most other trouble spots for ice jams are already mostly or completely frozen over. However, river ice is notoriously unpredictable, and the rarity of our ongoing cold snap may create additional minor ice jam issues in places that don`t typically have to deal with river ice. The bottom line is that when we expect very unusual cold conditions, it`s not unreasonable to expect some very unusual river ice issues somewhere. Water levels around ice jams can go up/down much faster than usual, so anyone living near a river should pay extra attention to water levels over the next few days and have a plan to respond if conditions change quickly. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Winter Weather Advisory until 10 PM EST this evening for MIZ065>067-071>074. MARINE...None. && $$ DISCUSSION...CAS AVIATION...Ceru HYDROLOGY...Thomas

NWS GRR Office Area Forecast Discussion