697 FXUS63 KGRR 092347 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 747 PM EDT Wed Sep 9 2026 .KEY MESSAGES... - Showers and Storms End This Afternoon/Evening - Low Chance Of Weekend Rain - Additional showers and storms Monday/Tuesday && .DISCUSSION... Issued at 230 PM EDT Wed Sep 9 2026 - Showers and Storms End This Afternoon/Evening Radar shows ongoing showers shifting to the south/east ahead of a cold front expected to pass in the coming hours. The passage of this front will cause showers and storms to come to an end. HREF mean SBCAPE shows a few hundred joules through the afternoon which supports isolated thunderstorm potential until precipitation clears the area. - Low Chance Of Weekend Rain Our next chance of precipitation arrives over the weekend as a cold front and weak shortwave cross the area. Weak moisture return is expected to keep much of the weekend dry and PoPs low. For those that see precipitation, amounts should be less than 0.10". - Additional showers and storms Monday/Tuesday A stronger system takes aim at the region Monday as the upper-level jet moves south into the region. A deepening low associated with this will lead to potentially breezy conditions as well as the chance for showers and storms. NBM probabilities suggest a 30-40% chance of over 1" of rainfall, highest across the northwest CWA, so will need to monitor for potential heavy rainfall. Given a modeled ample LLJ in place, even with questions on available instability, we`ll have to monitor potential for storm development. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 747 PM EDT Wed Sep 9 2026 Scattered to broken clouds at 2,000 feet may persist for the next couple hours but should dissipate as drier air flows in. Kept the potential for IFR visibility with mist or patchy fog Thursday morning, as skies partially clear out and surface winds go light. The consensus of short-term models favor some reduced visibility vicinity and E, SE, and S of GRR affecting most of the TAF sites. However, some factors potentially inhibiting fog include drier low-level air flowing in with 15-20 knots of wind at 500 feet, though some models relax those winds slightly just prior to sunrise. && .MARINE... Issued at 230 PM EDT Wed Sep 9 2026 Observations suggest the Small Craft Advisory/Beach Hazards Statement may be underperforming a bit bit given webcams do show some elevated waves will let the headlines ride until expiration this evening. Another Small Craft Advisory may ne needed Saturday associated with a cold frontal passage. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Beach Hazards Statement until 8 PM EDT this evening for MIZ037- 043-050-056-064-071. MARINE...Small Craft Advisory until 8 PM EDT this evening for LMZ844>849. && $$ DISCUSSION...Thomas AVIATION...CAS MARINE...Thomas

NWS GRR Office Area Forecast Discussion