355 FXUS63 KGRR 281038 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 638 AM EDT Mon Sep 28 2026 .KEY MESSAGES... - Dry through Tuesday - Showers and isolated thunder Tuesday night - Friday - Mild through Thursday, then cooler && .DISCUSSION... Issued at 234 AM EDT Mon Sep 28 2026 - Dry through Tuesday We`re looking at some patchy dense fog again early this morning. Hart, Fremont, and Ludington are at or near a quarter mile and a couple other locations around a half mile. Any fog that does develop will burn off by mid morning. High pressure remains entrenched across the Great Lakes extending west to the upper MS Valley and being held in place by the Mid Atlantic low. A light north wind will keep dewpoints comfortably in the 50s through Tuesday and we`ll see quite a bit of sunshine; IR loop shows scattered high clouds to the east and west. Once the low begins to move northeast today, the high will also drift east and we should develop a south flow by Tuesday. Tuesday will be another sunny day, but may see some high clouds begin to move in from the west later in the day. - Showers and isolated thunder Tuesday night - Friday The blocking low off the East Coast has delayed the arrival of the next cold front until Wednesday. The GFS and ECMWF are in pretty good agreement in showing showers/storms along the cold frontal boundary, extending to the low in western Kansas. Instability is very weak with positive LI`s and MUCAPE a couple hundred j/kg at best Wednesday into Thursday. That said, most ECMWF ensemble members produce rain during this time frame with the average around a half inch. The cold front will move south across the cwa Friday and take the precipitation with it. High pressure quickly builds in behind it for Saturday and much of Sunday. - Mild through Thursday, then cooler Average highs around around 70 currently and we`ll be in the mid 70s through Thursday before cooling into the mid 60s Friday, behind the cold front as h8 temps fall to around 5c from 18c Thursday. && .AVIATION /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 630 AM EDT Mon Sep 28 2026 IR loop shows an area of IFR cigs and vsbys moving south across the region. This will mix out by mid morning leaving sct250 through the rest of the day. Another good radiational cooling night is expected again tonight, resulting in MVFR/IFR vsbys after midnight. && .MARINE... Issued at 234 AM EDT Mon Sep 28 2026 Wind will be relatively light through Tuesday due to high pressure overhead. After that, the high will drift east and south winds will increase ahead of the next cold front. A small craft advisory may be needed Wednesday north of Grand Haven. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...04 AVIATION...04 MARINE...04

NWS GRR Office Area Forecast Discussion