457 FXUS63 KGRR 070609 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 209 AM EDT Sun Jun 7 2026 .KEY MESSAGES... - Next Chance For Thunderstorms Monday into Tuesday - Hot and Midweek with Chances (30-50 percent) for Thunderstorms && .DISCUSSION... Issued at 209 AM EDT Sun Jun 7 2026 - Next Chance For Thunderstorms Monday into Tuesday High pressure today will result in pleasant summer weather with highs in the upper 70s to mid 80s. Winds will be light and variable before becoming more easterly this afternoon. Thunderstorm chances return Monday as the upper level low over Oklahoma tracks northeast along the upper level ridge. Most of Monday will likely be dry, but could see some pop up thunderstorms develop during the afternoon before the better lift arrives Monday night into Tuesday with the trough axis and positive vorticity advection. With precipitable water values approaching 2 inches and slow storm motions localized heavy rain is possible. We remain in WPC`s marginal risk for rainfall exceeding flash flood guidance on Tuesday. Soundings also support that we could get some stronger winds with any isolated or multicell clusters of thunderstorms. - Hot and Midweek with Chances (30-50 percent) for Thunderstorms Dew points will be in the 60s and 70s through much of the upcoming week creating a humid environment. Temperatures will be on the rise each day as well with Wednesday and Thursday expected to be the hottest days of the week. It is these days we`ll need to monitor for heat indices approaching or exceeding 100. However there will be chances for thunderstorms both of these days that could impact temperatures and limit heat index values. Wednesday chances are lower in the 20s and 30s and mainly focused in the morning with lift at 850mb. Thursday chances are better (40 to 60 percent) during the late afternoon and evening. This could be another period to watch for severe thunderstorms. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 122 AM EDT Sun Jun 7 2026 VFR conditions are expected today with light and variable winds becoming easterly this afternoon and evening. && .MARINE... Issued at 209 AM EDT Sun Jun 7 2026 Light east to northeast winds today become more north to northwesterly along the lakeshore as the lake breeze develops this afternoon. Easterly winds then return this evening and become southeasterly for Monday. Thunderstorms will be possible late Monday afternoon with better chances Monday night into Tuesday. Additional chances for storms exist for Wednesday and Thursday. Small Craft Advisory conditions may be possible in the southwest winds expected Wednesday into Thursday and also may result in high swim risk conditions for areas north of Grand Haven. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...RAH AVIATION...RAH MARINE...RAH

NWS GRR Office Area Forecast Discussion