740 FXUS63 KGRR 251058 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 658 AM EDT Thu Jun 25 2026 .KEY MESSAGES... - Scattered showers and Isolated Storms Today - Fair Weather through the weekend - Heat With Storms Next Week && .DISCUSSION... Issued at 250 AM EDT Thu Jun 25 2026 - Scattered showers and Isolated Storms Today Any lingering showers and storms will continue to move eastward overnight. Calming winds, clearing skies and moisture at the surface from today`s rainfall should allow for patchy dense fog along with low clouds across lower Michigan this morning. That fog and any low clouds will lift and dissipate as the morning progresses. An upper level low will settle over the Upper Great Lakes today and should bring enough moisture and instability to allow for scattered showers and storms to Lower Michigan. The best chance will be through central and eastern Michigan this afternoon. - Fair Weather through the weekend Showers will lift eastward this evening as the low opens up and moves into eastern Ontario and northern New York. Zonal flow will then dominate the pattern through the weekend. A surface low is still on track to move through IN and Ohio Friday night into Saturday. The latest models have shifted the low slightly northward, which would bring some scattered showers to the southern tier of MI, which could include just south of the I 94 corridor. The mid range models and low position diverge on a solution, so while it is possible, it remains a low probability. If any precipitation that does occur, it will be light. North of the 94 corridor should remain dry. - Heat With Storms Next Week As discussed previously, a pattern shift is in store and the end of June brings us warmth, and the potential for tumult. A high pressure system will set up over the eastern USA, which will bring a cycle of warm air advection that will allow temperatures to vault into the 90s by Monday. Along with those highs will be dewpoints into the 70s. So a hot and humid airmass will be in store. So please plan for this heat accordingly as heat indices could get into the low 100s. While the heat and humidity will provide an environment favorable for storms, forcing remains a question. The high pressure could stifle any potential convection. Given that variability, afternoon and early evening convection from diurnal heating remains probable, but narrowing down on any specific location is difficult considering the uncertainty. So please, be prepared for heat and summertime scattered showers and storms. && .AVIATION /12Z TAFS THROUGH 12Z FRIDAY/... Issued at 651 AM EDT Thu Jun 25 2026 Periods of MVFR to IFR cigs and vsbys have formed over the region this morning. These will lift and dissipate mid to late morning. There is a chance for scattered showers and storms through northern and central lower but none are expected to intersect with any TAF locations. Another round of MVFR to IFR cigs and vsbys should develop this evening between 06Z and 12Z. && .MARINE... Issued at 330 AM EDT Thu Jun 25 2026 Southerly flow has slackened and winds and corresponding waves have calmed. Winds will shift to the north as the low moves eastward and the northerly flow will pick up slightly later today. However, it remains in the 10 to 15 kt range. There is a small potential very late in the day, just before sunset that waves could build into the 2 to 4 foot range just south of Muskegon and near Grand Haven. So far this is a low and brief probability but we will keep an eye on it. So overall not expecting issues for small craft or beach hazards. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Ceru AVIATION...Ceru MARINE...Ceru

NWS GRR Office Area Forecast Discussion