FXUS63 KGRR 240534 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 134 AM EDT Fri Oct 24 2025 .KEY MESSAGES... - Lake Effect Showers Ending Tomorrow - Mostly Dry and Cool Next Week && .DISCUSSION... Issued at 337 PM EDT Thu Oct 23 2025 - Lake Effect Showers Ending Tomorrow The big upper low that has brought the cyclonic flow and lake effect rain showers will be slowly moving east on Friday and rising heights along with warm advection will bring the rain showers to an end. Cloud should prevent temperatures from falling below freezing tonight despite cold air mass, but clearing on Friday night could allow widespread freezing temperatures by Saturday morning. - Mostly Dry and Cool Next Week Shortwave trough topping the longwave western CONUS ridge damps out across the Great Lakes on Saturday and a closed upper low over the Southern Plains moves east and forms a rex block for Sunday into next week. This is a complex pattern that models have been handling in different ways, but the rex block appears to be maintained by an upper low or lows retrograding into the Great Lakes from the NE CONUS by Tuesday. This may bring a slight chance of showers, but the higher precip chances appear to remain south of Lower Michigan, in an area of f-gen on the northern periphery of a sfc low tracking across the Ohio Valley and into the NE CONUS. This is followed by an upper trough axis and strong cold advection by the end of the week with cold rain and snow showers possible. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 134 AM EDT Fri Oct 24 2025 VFR conditions should rule through this forecast period, however we will maintain clouds for most of the period. We currently have a deck of clouds mainly between 5-6k ft agl across all of the terminals. These should persist, and maybe even lower slightly by daybreak. They will be reinforced by diurnal development through late afternoon. The clouds should then slowly clear out from SW to NE this evening into the early overnight hours, and winds will go light and variable. && .MARINE... Issued at 337 AM EDT Thu Oct 23 2025 No changes needed to the ongoing SCA that remains in effect through 2 pm Friday. Cold pool remaining over the area along with a continued solid flow from the NW over the warmer waters will keep winds and waves up through tonight. We will see winds diminish early Friday, and waves should come down sufficiently by the current end time of 18z Friday. Waterspouts will continue to be possible today, before tapering off tonight. We should have a decent break in the winds and waves then from Friday afternoon through the first part of Sunday. Winds will come up by Monday, bringing the possibility of another SCA at that time. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory until 2 PM EDT this afternoon for LMZ844>849. && $$ DISCUSSION...Ostuno AVIATION...NJJ/Thomas MARINE...Thomas