795 FXUS63 KGRR 232300 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 700 PM EDT Wed Sep 23 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 /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 700 PM EDT Wed Sep 23 2026 Ceilings around 5,000 feet in southern Michigan may tend to scatter overnight. From 01 until 06 Z, there may be about 20 knots of LLWS from 1,500 feet to ground as winds at 1,500 feet become approximately 09028KT. Daytime cumulus cloud development after 14 or 15 Z may initially be below 3,000 feet, scattered to broken, then after 18 Z should climb above 3,000 feet. && .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...CAS MARINE...04

NWS GRR Office Area Forecast Discussion