728 FXUS63 KGRR 130841 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 441 AM EDT Fri Mar 13 2026 .KEY MESSAGES... - Rain and Snow, Briefly Heavy Snow in Central Michigan This Morning - Windy Today - Winter Storm Possible Saturday Night Through Monday && .DISCUSSION... Issued at 412 AM EDT Fri Mar 13 2026 - Rain and Snow, Briefly Heavy Snow in Central Michigan This Morning No changes to the existing winter weather advisory. Robust clipper system moving through today will bring a shot of 1 inch per hour snowfall rates to Central Michigan for the morning commute (SPC mesoscale discussion 236 for more details). The HREF has been signaling this to occur especially between 6 and 9 AM for areas near and north of Ludington, White Cloud, Big Rapids/Canadian Lakes, and Mount Pleasant. Around 6 inch totals are most favored in Lake, Osceola, and Clare counties. Farther south toward I-96 and I-94, a tendency for more of a snow to rain and back to snow with more minor accumulations. - Windy Today No change to the high wind warning. Upstream observations in northern Illinois suggest strong wind gusts up to 60 mph possible this morning with onset of precipitation. May be a bit of lull in the peak gusts later in the morning given limited mixing due to clouds and precipitation. Also with a slight southward adjustment to the low`s track, a midday lull may be more pronounced in the northernmost row of counties. But additional strong wind gusts are possible throughout the warning area during the afternoon with modest cold air advection. End time of the high wind warning might need to be bumped a couple hours later in the evening, closer to 10 PM. - Winter Storm Possible Saturday Night Through Monday Matching up with APX on a winter storm watch for Saturday night through Monday for areas near/north of M-20. While much of APX will be square in the threat for a significant winter storm, our southern portion of Central Michigan has some potential (50 to 60 percent) to catch moderate storm-level impacts but it is not quite settled. Our area`s weather on Sunday will be especially sensitive to the exact track of the low pressure center, and the latest ECMWF ENS envelope has shifted slightly north, which reduces our winter storm potential slightly. However, there remain solutions within the envelope that do have the low passing through SE Michigan which would entail higher impacts still possible in the watch area. WSSI-P indicates about a 20-30 percent chance of major impacts given those solutions. Expecting snow late Saturday night ahead of the developing low, followed by warming (especially in southeastern locations near and southeast of the low`s track) on Sunday. Can`t rule out a thunderstorm on Sunday but MUCAPE is progged to be fairly weak. If storms do occur, there is a marginal risk near and south of I-96 for severe wind gusts given the strengthening low-level wind field. There is potential for ice accretion from freezing rain in Central Michigan Sunday through Sunday night, and some of the southern model solutions have been producing over a quarter- inch of ice. Behind on the backside of the low on Monday, a change over to lake- enhanced snow and strong winds is expected, with more of Southwest Michigan getting in on winter impacts. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 143 AM EDT Fri Mar 13 2026 Low confidence in these TAFs verifying perfectly hour by hour, but high confidence in this being a difficult and unideal day for flying. The weather will be as ugly as these TAFs look, with temporary changes to flight categories around MVFR/IFR as visibilities and ceilings vary along with precipitation intensity and rain/snow type. The wind will also gradually veer from southeast to southwest to northwest throughout the course of the day. LLWS will be present this morning. Sustained winds today will often be 20 to 25 knots with gusts 35 to 45 knots, perhaps peaking once or twice around 50 knots. && .MARINE... Issued at 441 AM EDT Fri Mar 13 2026 Storm force gusts from the southwest are occurring now and remain possible through the day from the west, especially south of Pentwater to St Joseph. A gale warning is also in effect to the north of Pentwater. Winds subside below gale by 11 PM, then a small craft advisory will be needed through mid Saturday morning. Hazardous conditions for small craft develop again late Saturday night. Gales are likely and storm force winds are possible Sunday night and Monday. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...High Wind Warning until 8 PM EDT this evening for MIZ037-043>046- 050>052-056>059-064>067-071>074. Winter Weather Advisory until 2 PM EDT this afternoon for MIZ037>040-043>046-051-052. Winter Storm Watch from late Saturday night through Monday evening for MIZ037>040-043>045. MARINE...Storm Warning until 11 PM EDT this evening for LMZ844>848. Gale Warning until 11 PM EDT this evening for LMZ849. && $$ DISCUSSION...CAS AVIATION...CAS MARINE...CAS

NWS GRR Office Area Forecast Discussion