210 FXUS63 KGRR 211850 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 250 PM EDT Sun Jun 21 2026 .KEY MESSAGES... - Rain chances this afternoon and overnight - Cooler than normal temperatures persist through the week && .DISCUSSION... Issued at 208 PM EDT Sun Jun 21 2026 - Rain chances this afternoon and overnight Beneficial light rain for some with no significant impacts expected this afternoon and overnight. Focus for rain is near and south of I-96 with better chances for more rain the further south you go. Current ensemble probabilities for near I-94 show around 75% chance for one-quarter inch or more, 50% chance for one-half inch or more of rain by tomorrow and around a 10% chance of one inch or more. Up around I-96 those probabilities drop to around 35% chance for one- quarter inch or more, around 15% chance for one-half inch or more and near zero percent chance of one inch or more. Up around US-10, the probabilities for one-tenth of an inch or more and one- quarter inch or more are both near 0%. So most likely case is around a quarter-inch or less near I-96 and a half-inch or so near/south of I-94. Again...no significant impacts expected from this rain. Some lightning may be possible...though chances for that should be better closer to and south of the Indiana border than up in lower Michigan. - Cooler than normal temperatures persist through the week No change to the overall pattern expected this week with temperatures generally hovering in the mid 70s for highs and in the 50s for lows. We could see some warming to more summer like temperatures next weekend into the last few days of June with models indicating warming temps potentially through the 4th of July weekend. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 131 PM EDT Sun Jun 21 2026 Cloud bases will lower throughout the afternoon as rain moves toward the terminals. Light steady rain and MVFR/IFR ceilings are expected as the evening progresses through the overnight hours. Ceilings will improve Monday morning as low pressure moves east and takes the rain with it. && .MARINE... Issued at 208 PM EDT Sun Jun 21 2026 Winds and waves begin to increase midday Monday and continue through Monday evening. Small craft and beach hazards statement may be needed for some if not all of the coastal zones tomorrow. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Maczko AVIATION...04 MARINE...Maczko

NWS GRR Office Area Forecast Discussion