045 FXUS63 KGRR 311137 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 737 AM EDT Tue Mar 31 2026 .KEY MESSAGES... - Severe storm chances today - Freezing Rain Wednesday Night and Thursday && .DISCUSSION... Issued at 302 AM EDT Tue Mar 31 2026 - Severe storm chances today A wave of low pressure trailing a cold front will impinge on Lower Michigan this afternoon and evening with a chance for strong to severe storms ahead of the front. The best chance will be across the southern half of the forecast area where instability is available and the CAMs show two rounds of convection occurring between 18Z and 00Z as the front pushes south. Both of them have the potential to grow upscale from cellular to linear as they move southeast. The main threat will be hail in strong isolated updrafts or multicell clusters and severe wind gusts along bowing line segments. The storms will exit to the south as the front clears the forecast area by about 02Z. We will also have to watch for flooding issues if training of storms persists. - Freezing Rain Wednesday Night and Thursday Cold high pressure will build in for mid-week as Plains cyclogenesis gets underway with sfc low tracking through Wisconsin on Thursday. This will set up the northeast CWA for another icing event. At this point it looks like icing of a quarter inch is possible in Clare and Osceola Counties. Future trends in sfc low strength and path will be monitored closely. && .AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/... Issued at 737 AM EDT Tue Mar 31 2026 An active period of aviation weather is expected over the course of the next 24 hours. A stationary front is located across portions of Central Lower Michigan today stretching from near Ludington to near Alma. The TAF sites are all in the warmer air south of the front and are currently VFR. That will change as we move forward as the front is expected to move south bringing with it periods of showers and thunderstorms today. Storms are essentially possible from later this morning, 15z or so, through roughly 00z this evening. The front will also bring with it lower ceilings. MVFR and IFR ceilings will sag southward with the front invading all of the TAF sites this afternoon and evening. IFR ceilings will be most dominant between 00z and 04z. Overnight a slight improvement to MVFR will likely occur. Gusty southwest winds will continue today ahead of the front. && .MARINE... Issued at 302 AM EDT Tue Mar 31 2026 Hazardous winds and waves for small craft are expected much of this week. The current SCA goes through 12Z Wednesday. There will be a possible lull on Wednesday. Winds and waves will pick up again Wednesday night and persist into the weekend, && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory until 8 AM EDT Wednesday for LMZ844>847. && $$ DISCUSSION...Ostuno AVIATION...Duke MARINE...Ostuno

NWS GRR Office Area Forecast Discussion