241 FXUS63 KGRR 200604 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 204 AM EDT Sat Jun 20 2026 .KEY MESSAGES... - Cooler than normal with occasional rain && .DISCUSSION... Issued at 204 AM EDT Sat Jun 20 2026 - Cooler than normal with occasional rain The Great Lakes region will continue to be in a fast quasi-zonal flow regime on the southern edge of persistent upper troughing across eastern Canada into next week. This will keep temperatures below normal with fast-moving shortwave troughs bringing the chance for rain late Sunday night and again on Wednesday. The best chance for rain will be across southern Lower Michigan on Sunday night as low pressure tracks across northern Indiana and Ohio. An area of mid-level frontogenetic forcing should bring steady rain across the I-94 corridor with QPF of around one inch by the time the rain ends on Monday. There will be a sharp gradient to the north with around a quarter inch along I-96 and less than a tenth of an inch north of there. A weaker low follows for Wednesday in northwest flow and precip amounts will probably be less than a quarter inch. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 204 AM EDT Sat Jun 20 2026 VFR conditions will continue through today and tonight. West winds may gust over 20 knots at times this afternoon before decreasing blo 10 knots this evening. && .MARINE... Issued at 204 AM EDT Sat Jun 20 2026 Fairly tranquil conditions into Sunday then winds and waves will increase Sunday night as low pressure passes just south of Lake Michigan. A SCA may be needed for Monday. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Ostuno AVIATION...Ostuno MARINE...Ostuno

NWS GRR Office Area Forecast Discussion