011 FXUS63 KGRR 091859 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 259 PM EDT Thu Jul 9 2026 .KEY MESSAGES... - Scattered Thunderstorms Tonight - Upper High builds in Next Week && .DISCUSSION... Issued at 258 PM EDT Thu Jul 9 2026 - Scattered Thunderstorms Tonight Storms have remained below severe limits so far this afternoon. There is still a threat for hail and damaging winds this evening across the southeast zones where instability is greatest. A cold front slowly sinks south overnight then slows and stalls on Friday just south of Lower Michigan with a low chance of lingering showers across the far south. - Upper High builds in Next Week Heights rise early next week with an upper high centered across the upper Mid-west and Northern Plains extending into Michigan early in the week, bringing hot and dry weather. The details are still to be determined, but height falls are expected mid-week as upper troughing develops across eastern Canada. This could result in a cooling trend by mid to late week and possibly some much needed rainfall if MCS activity forms along the top of the ridge and advects into Michigan. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 126 PM EDT Thu Jul 9 2026 Scattered thunderstorms are likely through the afternoon, and based on development trends have gone TEMPO Thunder at LAN/JXN. Convective LLWS and microbursts with winds of 35+ knots are possible with any storms. Thunderstorms diminish this evening followed by a period of fog and low cloud development overnight. MVFR conditions are likely, with IFR possible mainly at LAN. Some discrepancy in guidance over the extent of low-level stratus vs fog coverage, but flight category forecast remains the same. Gusts to 15 knots, higher in thunderstorms, continue through the afternoon with light winds overnight. Then winds increase to 3-8 knots from the north to northwest Friday. && .MARINE... Issued at 258 PM EDT Thu Jul 9 2026 Scattered thunderstorms will be ending from north to south this evening with a low chance for gusty winds and small hail. Then high pressure builds in for the weekend and into next week. North winds could gust over 20 knots Friday evening as the high builds in then winds should be blo 15 knots for most of the weekend. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION... AVIATION...Thomas MARINE...Ostuno

NWS GRR Office Area Forecast Discussion