384 FXUS63 KGRR 262328 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 728 PM EDT Sun Oct 26 2025 .KEY MESSAGES... - Fair weather will dominate the pattern into mid week - More active pattern the latter half of the week into the weekend && .DISCUSSION... Issued at 257 PM EDT Sun Oct 26 2025 - Fair weather will dominate the pattern into mid week High pressure that is resting over Ontario and Quebec will dominate the weather pattern for at least the next few days. A large upper level low remains just off the east coast with a low traversing through the Tennessee Valley and a large upper level trough is setting up over the intermountain west. That will allow for dry weather with clear skies causing slightly below normal min temperatures and around normal Max Temps through the first half of the week. - More active pattern the latter half of the week into the weekend The second half of the week is when things begin to get interesting. The interplay from the three previously mentioned low pressure systems will dominate the forecast period. By Tuesday evening, the trough to the west should infiltrate down through central Canada and through the Great Plains as a High pressure system builds over the West Coast. The weak low moving through the Tennessee valley will move eastward and get enveloped by low off the east coast that should begin to retrograde west ward into the Mid Atlantic region. The upper level ridge should lift northward due to this and the upper level low from the west will get pushed southward through Illinois and through Indiana, Ohio, etc. By Wednesday the High will continue to get pushed northward and the strong low from the west will move through central US and into the Ohio Valley area. The main caveat in the models is their handling of the retrograding low. However, They are all in good agreement on the High pressure and the low from the west. That interaction should keep Michigan dry through Wednesday, though there is a low chance for showers if the low shifts to the north. The mid to long range models and ensembles are in fair agreement that he upper level low will shift northward through the Mid Atlantic Thursday into Friday, and into Quebec, Friday into Saturday. What that means for Michigan, is that we will be on the backside of the low, with the easterly flow then shifting to northerly flow with lake enhanced showers possible late Thursday through Friday. There remains quite a bit that could shift but it could be a wet Halloween. The good news, is that the dewpoints should be above freezing with an unsaturated DGZ, so snow is not likely. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 728 PM EDT Sun Oct 26 2025 VFR conditions will continue through Monday, except for some shallow ground fog at JXN late tonight which should quickly dissipate after sunrise. East winds tonight AOB 5 knots will increase to around 10 knots on Monday. && .MARINE... Issued at 303 PM EDT Sun Oct 26 2025 Offshore winds will continue the next several days, so waves will generally be a foot or less close to the coast, and about 2 to 4 feet a couple miles out. Winds will get stronger on Monday night into Tuesday as low pressure tracks south and then east of Lower Michigan. East to northeast winds will continue to gust 25 knots or greater Tuesday through Thursday and a Small Craft Advisory will be needed during that time. The highest winds, gusting to 30 knots, are expected south of Grand Haven. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Ceru AVIATION...Ostuno MARINE...Ostuno

NWS GRR Office Area Forecast Discussion