606 FXUS63 KGRR 232341 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 741 PM EDT Thu Apr 23 2026 .KEY MESSAGES... - Slight chance of showers/storms this afternoon/evening, better chance Friday - Chance of storms Monday - Cooler next week && .DISCUSSION... Issued at 224 PM EDT Thu Apr 23 2026 - Slight chance of showers/storms this afternoon/evening, better chance Friday There`s been a surge of moisture today across the cwa behind a warm front and surface dewpoints are near 60 in many locations. Additionally, a weak short wave is riding over the upper ridge across the state. As such, some of the CAMs are pointing toward some isolated convection developing later this afternoon after 3-4 pm, mainly southeast of Grand Rapids. SBCAPE is progd to increase to 1000-1500 j/kg this afternoon. Any storms that develop, however, are expected to be sub-severe as bulk shear is progd to remain below 20 knots which will limit storm organization. The next chance of storms will arrive Friday when a cold front moves through the region. RRFS-EMC progs point toward decaying showers/storms moving across the cwa Friday morning with a potential refiring Friday afternoon. The clouds and lingering precipitation Friday morning may keep a lid on instability through much of the cwa Friday. CAMs show this with storms redeveloping east of Lansing Friday afternoon where morning convection didn`t have as much of an influence on atmospheric instability. Nevertheless, CAMs also show some redevelopment along the cold front after 20z east of US-131, so there`s likely to be some recovery after the morning precipitation with a likelihood of strong storms southeast of the cwa. - Chance of storms Monday After a weekend featuring partly to mostly sunny skies, highs in the mid 60s and dewpoints in the 40s, the next system will arrive Monday night and Tuesday. The next cold front will move in Monday night. SBCAPE is progd near 500 j/kg early Tuesday morning. Thus storms are possible, but the late night arrival will diminish chances for severe storms. - Cooler next week Once the cold front moves through Tuesday, h8 temperatures will fall from 12c Tuesday to 0c Wednesday morning. That will set the stage for cooler weather mid to late week. We`ll see highs in the mid 50s Wednesday and Thursday. Surface high pressure will build in from the northwest, but zonal flow aloft will likely supply some high clouds. && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 741 PM EDT Thu Apr 23 2026 VFR conditions will continue into Friday morning then MVFR is possible in the late morning and afternoon as rain showers move in from the west. There could be an isolated thunderstorm in the afternoon but coverage is low enough that it has been left out of the forecast for now. South winds around 10 knots overnight will go southwest on Friday afternoon. && .MARINE... Issued at 224 PM EDT Thu Apr 23 2026 High pressure overhead is keeping wind and waves below advisory criteria. South winds will increase Friday ahead of the next cold front and waves will build to 2 to 4 feet north of Grand Haven. It`s not out of the question that a small craft advisory may be needed Friday, but confidence is`t high enough to issue yet. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...04 AVIATION...Ostuno MARINE...04

NWS GRR Office Area Forecast Discussion