790 FXUS63 KGRR 311028 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 628 AM EDT Fri Jul 31 2026 .KEY MESSAGES... - Increasing clouds today. Showers/storms tonight and Saturday. - Showers middle of next week && .DISCUSSION... Issued at 238 AM EDT Fri Jul 31 2026 - Increasing clouds today. Showers/storms tonight and Saturday. IR loop shows abundant high clouds moving over the top of the ridge and across the state. Clouds will increase today as low pressure over Iowa strengthens and moves east. Latest models are a little more bullish on rain chances and amounts across the cwa tonight and Saturday. The short wave accompanying the surface low is stronger which in turn is helping to draw moisture northward. Showers and scattered thunderstorms are expected to develop by late evening across the western cwa and then move eastward. Given bulk shear values 20-25kts, severe weather will likely remain south of the cwa where shear is greater. Locally heavy rainfall may be a bigger threat. Precipitable water values increase to over 2 inches after 06z tonight suggesting that a few of the heavier showers and/or storms could be prolific rain producers. WPC has painted the cwa in a slight risk for excessive rainfall for tonight and Saturday. Thus localized flooding isn`t out of the question. Total qpf from tonight through Saturday is in the half inch to inch range basin wide; locally higher. The low will move east Sunday and rainfall chances will diminish slowly throughout the day from northwest to southeast. Clouds and precipitation will hold highs in the mid 70s Saturday and Sunday. - Showers middle of next week Another cold front and upper trough will move across the state during the middle of next week generating some showers and storms. Despite the deterministic versions of the ECMWF and GFS being somewhat out of phase, the ensembles of both show precipitation during the middle of the week. Highs will be in the lower to mid 80s through next week. && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 625 AM EDT Fri Jul 31 2026 High clouds will lower throughout the day as low pressure approaches from the west. Light rain will develop after midnight too and cigs will fall to MVFR at MKG/GRR prior to sunrise. Elsewhere cigs will likely remain VFR through the period. && .MARINE... Issued at 238 AM EDT Fri Jul 31 2026 Wind and waves will not pose a threat to small craft today. However, as low pressure passes to the south Saturday, northeast winds will increase and a small craft advisory may be needed. Highest waves Saturday will be closer to the 5 mile point offshore. Gusty winds will continue into Sunday as high pressure builds in to the region again. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...04 AVIATION...04 MARINE...04

NWS GRR Office Area Forecast Discussion