441 FXUS63 KGRR 301024 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 624 AM EDT Wed Sep 30 2026 .KEY MESSAGES... - Rain through Thursday night - Cooler weekend, frost/freeze potential && .DISCUSSION... Issued at 238 AM EDT Wed Sep 30 2026 - Rain through Thursday night A fairly long duration light rain event is unfolding across Lower MI. Radar shows light rain from the central UP southwest to New Mexico along a cold front moving eastward across northern Wisconsin. This frontal boundary will sag south across the central cwa today and then remain quasi stationary until Thursday night. Meanwhile, abundant moisture moving north from the Gulf in conjunction with subtropical moisture from the Pacific will help to create light to moderate rainfall during the next 48 hours. We`ll wait until low pressure over the southern Plains finally gets kicked out by a northern stream short wave for the frontal boundary across the cwa to finally move south. That will allow cooler air to move into the region. Instability is somewhat anemic with this system and so we are expecting mostly rain. However, instability increases a bit tonight and we could see a non severe thunderstorm or two south of I-96. Total QPF 1-2 inches is possible...highest over the west central cwa. Rain will end from north to south early Friday once the cold front moves south, leading to some sunshine late in the day. .KEY MESSAGES... Highs will be in the mid to upper 60s today through Friday. - Cooler weekend, frost/freeze potential H8 temperatures fall from 16c to 6c between Thursday afternoon and Friday afternoon. If skies clear Friday, we could see subfreezing temperatures along US-10 Friday night and mid 30s south to M-46. Another cold front moves through Sunday night and sends sends h8 temperatures down to -2c by Monday morning. Lows Monday morning will be in the lower 30s across the northern cwa, but it`s Tuesday morning that will be the coldest of the season...so far...with temperatures in the mid to upper 20s over the northern cwa and lower to mid 30s elsewhere; frost/freeze headlines will most likely be needed Monday night. Highs Tuesday will be around 60...almost 10 degrees below normal. && .AVIATION /12Z TAFS THROUGH 12Z THURSDAY/... Issued at 618 AM EDT Wed Sep 30 2026 Radar shows a large area of light rain slowly moving across the region and currently falling at MKG. GRR will see light rain begin within the next hour. A cold front will slowly move south across the Lower Peninsula and stall over southern Lower later this afternoon before lifting north tonight as low pressure approaches from the southwest. IFR cigs will be noted north of the boundary. Once the front lifts north, the southern terminals will likely lift back up to VFR after midnight. && .MARINE... Issued at 238 AM EDT Wed Sep 30 2026 Based on latest wave height guidance, we`ve extended the headlines south to Holland. No change to the duration. Waves will increase to 3 to 7 feet today north of Holland and then diminish later tonight. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Beach Hazards Statement through Thursday morning for MIZ037-043- 050-056. MARINE...Small Craft Advisory until 8 AM EDT Thursday for LMZ846>849. && $$ DISCUSSION...04 AVIATION...04 MARINE...04

NWS GRR Office Area Forecast Discussion