676 FXUS63 KGRR 071706 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI Issued by National Weather Service Detroit/Pontiac MI 106 PM EDT Thu May 7 2026 .KEY MESSAGES... - Cool with occasional chances for showers && .DISCUSSION... Issued at 234 AM EDT Thu May 7 2026 - Cool with occasional chances for showers Upper troughing across the Great Lakes will persist into next week. Temperatures will remain cool with a frost threat again Thursday night. Frost/Freeze potential increases for Saturday, Sunday and Monday nights as well. Clipper type lows will occasionally bring showers in a northwest flow regime. A shortwave trough moves through today and tonight with the diurnal increase in sfc-based instability this afternoon and evening resulting in isolated to scattered showers. The pattern repeats for Saturday and Tuesday. The Tuesday low should have deeper moisture to work with, but is moving fast enough to limit the chances of excessive rainfall. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 106 PM EDT Thu May 7 2026 Diurnal cumulus field is gradually increasing in coverage outside the Lake Michigan shaddow. Additional clouds with a few showers is working across northern Illinois. Clouds and showers are expected to increase in coverage through the afternoon and will traverse the airspace of the southern terminals early this evening. Ceilings will remain VFR with this weak system. The somewhat gusty west flow this afternoon will quell quickly this evening and become light and variable overnight. Patchy ground fog may affect a few inland terminals with a little bit more near surface moisutre in place tonight. High clouds with light westerly winds are expected on Friday. && .MARINE... Issued at 234 AM EDT Thu May 7 2026 West winds today could gust over 20 knots at times, otherwise winds and waves will remain relatively light into the weekend. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Ostuno AVIATION...Mann MARINE...Ostuno

NWS GRR Office Area Forecast Discussion