628 FXUS63 KGRR 121130 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 630 AM EST Thu Nov 12 2026 .KEY MESSAGES... - Lake Effect Rain and Snow Showers && .DISCUSSION... Issued at 208 AM EST Thu Nov 12 2026 - Lake Effect Rain and Snow Showers Cyclonic flow continues across Lower Michigan through Saturday as an amplified omega block forms over the CONUS with upper troughing to the east and a sharp ridge to the west. Lake effect rain and snow showers will be confined to mostly near and off the Lake Michigan coast in north flow. Some light snow accums are possible across the northwest zones. The blocking regime breaks down over the weekend and showers end as heights rise. The amplified ridging flattens as it moves east bringing dry and mild weather into the middle of next week. && .AVIATION /12Z TAFS THROUGH 12Z FRIDAY/... Issued at 628 AM EST Thu Nov 12 2026 Areas of IFR conditions today with occasional rain and snow showers, improving to MVFR and then VFR by evening. North winds will gust to 20 knots at times today. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory until 7 PM EST Friday for LMZ844>849. && $$ DISCUSSION...Ostuno AVIATION...Ostuno

NWS GRR Office Area Forecast Discussion