668 FXUS63 KGRR 240553 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 153 AM EDT Thu Sep 24 2026 .KEY MESSAGES... - Dry and warmer through Tuesday, then rain. && .DISCUSSION... Issued at 142 PM EDT Wed Sep 23 2026 - Dry and warmer through Tuesday, then rain. A large area of high pressure was noted over western Quebec this afternoon. Skies were clear to the north and west of the high. However, IR loop revealed cloudy skies to the south of the ridge axis where low pressure was located near the Ohio Valley. The northern edge of the cloud shield has encroached upon the southern row of counties. While much of the cumulus will dissipate with sunset, we`ll likely see some mid and high clouds overhead tonight and tomorrow...most numerous from I-96 southward. The medium range models are in good agreement through the weekend and confidence is high we`ll have dry weather with a slight warming trend through Monday. In fact, all of the ECMWF ensemble members show no precipitation until next Tuesday. Thus, comfortable early fall weather is upon us with highs in the upper 60s to lower 70s and dewpoints in the 40s and 50s. The blocking upper ridge will begin to break down early next week as a northern stream short wave phases with a southern stream wave. This combination will carve out a deeper upper trough over the Rockies which will push a cold front toward the Great Lakes early next week. We`ll see south flow pull some moisture northward resulting in rain showers when the cold front moves across Lake MI Tuesday night and Wednesday. This far out, the models aren`t showing much instability so we`ll go with mostly rain at this point Tuesday night and Wednesday. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 152 AM EDT Thu Sep 24 2026 VFR weather is expected the next 24 hours with zero restrictions to ceiling or visibility. There are some VFR cloud bases across Southwest Lower Michigan (around 5,000ft) at 06z, but we expect these to exit the state to the southwest before daybreak. Some cumulus development will occur today but we are not anticipating much more the FEW050 given high pressure firmly in control. Winds today will be from the east at 5 to 10 knots. && .MARINE... Issued at 142 PM EDT Wed Sep 23 2026 A persistent high over western Quebec will supply the region with an east wind through Saturday. The off shore wind combined with a weak pressure gradient will result in waves less than 2 feet...highest near the 5 mile mark off shore. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...04 AVIATION...Duke MARINE...04

NWS GRR Office Area Forecast Discussion