787 FXUS63 KGRR 260528 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 128 AM EDT Fri Jun 26 2026 .KEY MESSAGES... - Scattered afternoon/evening storms north - Building heat && .DISCUSSION... Issued at 136 PM EDT Thu Jun 25 2026 - Scattered afternoon/evening storms north Radar shows scattered convection as developed over the northern cwa near US-10. We`ll continue to monitor for the potential for isolated severe storms as there is sufficient instability, moisture, but marginal shear values. These showers/storms will dissipate after sunset. - Building heat The developing story across the Great Lakes will be the building heat that will likely result in heat headlines next week. A deepening upper trough over the northern Rockies will result in a building ridge over the central US including the Great Lakes. H8 temperatures are expected to increase from 18C Monday to 24C late Tuesday. That type of heat will send surface temperatures into the lower to mid 90s for much of next week. Most models increase dewpoints into the lower to mid 70s during the heat wave which will make the air feel incredibly humid. The high heat and humidity may result in scattered convection if the cap doesn`t become too strong. Overall, though, we don`t anticipate much precipitation next week due to short waves riding over the top of the ridge well north of the cwa. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 126 AM EDT Fri Jun 26 2026 The clear skies and calm winds will lead to another round of low clouds that will settle over the region overnight. Expect MVFR cigs and vsbys with IFR possible, especially at LAN and potentially JXN. Best chance for reducing conditions will be from 09Z until 12Z. Expect improving conditions after sunrise with VFR from mid morning onward. && .MARINE... Issued at 136 PM EDT Thu Jun 25 2026 A weak pressure gradient will limit marine issues as we move toward the weekend. However, dewpoints in the 70s over cold water may result in dense fog by the end of the weekend through much of next week. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...04 AVIATION...Ceru MARINE...04

NWS GRR Office Area Forecast Discussion