227 FXUS63 KGRR 241042 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 642 AM EDT Fri Jul 24 2026 .KEY MESSAGES... - Northwest Flow Regime Continues with Low Confidence for Rain Chances && .DISCUSSION... Issued at 204 AM EDT Fri Jul 24 2026 - Northwest Flow Regime Continues with Low Confidence for Rain Chances A persistent western CONUS upper ridge and eastern CONUS upper trough will keep the Great Lakes region in northwest flow with occasional chances for rain/thunderstorms, but low confidence on coverage and QPF amounts...and perhaps similar to the under- performing events from the past week. A weak shortwave trough moves through Saturday night. Not much moisture available and the best lift is off to the east, so low/slight chance POPs at best. Another trough moving through late Monday into Tuesday has better moisture to work with and is amplifying as it moves though, so high chance to likely POPs in NBM appear possible if not reminiscent of the convectively-lacking event of last Monday. The longwave upper trough amplifies late in the week with a cold front bringing another chance of rain on Friday followed by another cool down for next weekend. && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 642 AM EDT Fri Jul 24 2026 VFR conditions will continue through Saturday morning. Winds will be light and variable. && .MARINE... Issued at 204 AM EDT Fri Jul 24 2026 Calm conditions today then a SCA may be needed for Saturday and Saturday night and again Monday and Tuesday as a couple low pressure centers quickly move through with southwest flow on Saturday and Monday and northerly flow on Tuesday. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Ostuno AVIATION...Ostuno MARINE...Ostuno

NWS GRR Office Area Forecast Discussion