963 FXUS63 KGRR 090629 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 229 AM EDT Sat May 9 2026 .KEY MESSAGES... - Thunderstorms SE Lower Michigan this Afternoon - Frost/Freeze the Next Three Nights && .DISCUSSION... Issued at 228 AM EDT Sat May 9 2026 - Thunderstorms SE Lower Michigan this Afternoon A cold front pushes through today with modest moisture and instability across the southeast forecast area to initiate a line of storms in the afternoon. High resolution CAMS show most of the heavier storms will moves south and east of Ingham to Jackson Counties, but it will be a close call. The threat should end as the cold front clears the area by 5 pm. - Frost/Freeze the Next Three Nights Cool high pressure builds in for tonight with clearing skies and diminishing winds. This will allow good radiational cooling conditions and another night of frost and freezing temperatures for the northern forecast area. A Freeze Warning and Frost Advisory has been issued for that area. Sunday and Monday nights will be even colder with an expected expansion of the Frost/Freeze headlines for most or all of the forecast area. Low pressure will bring rain on Tuesday as a clipper type low moves through in fast northwest flow regime. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 228 AM EDT Sat May 9 2026 VFR conditions will continue into Sunday morning. South winds could gust to 20 knots at times this afternoon. && .MARINE... Issued at 228 AM EDT Sat May 9 2026 Winds and waves will increase late tonight and marginal SCA conditions are expected this morning ahead of the advancing cold front. Winds and waves will decrease this afternoon as high pressure builds in and remain fairly light until Tuesday when the high moves east and south winds increase. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Frost Advisory from 2 AM to 8 AM EDT Sunday for MIZ037-043>046. Freeze Warning from 2 AM to 8 AM EDT Sunday for MIZ038>040. MARINE...Small Craft Advisory until 1 PM EDT this afternoon for LMZ844>849. && $$ DISCUSSION...Ostuno AVIATION...Ostuno MARINE...Ostuno

NWS GRR Office Area Forecast Discussion