800 FXUS63 KGRR 191035 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 635 AM EDT Sun Jul 19 2026 .KEY MESSAGES... - Dry With Smoke Today - Showers and Storms Monday Night into Tuesday - Dry Conditions Tuesday Night into Late Week && .DISCUSSION... Issued at 212 AM EDT Sun Jul 19 2026 - Dry With Smoke Today Surface high pressure and a dry atmosphere will keep conditions dry today as northerly post-cold frontal flow brings smoke back into the area. According to Michigan`s Dept. of Environment, Great Lakes, and Energy; The latest HRRR and RRFS smoke models show a band of smoke moving southward through Southern Lower Michigan. This will create a period of air conditions that will be Unhealthy for Sensitive Group period tomorrow morning and afternoon. Latest model trends, along with a pattern shift shows a reduction in smoke tomorrow evening. - Showers and Storms Monday Night into Tuesday Storms are expected to develop across the Upper Midwest Monday, driven east by a shortwave and an attendant cold front. There are questions given strong MLCIN as to the extent that these storms make it across the lake. Regardless, given the dynamics rainfall is likely. One thing we will have to watch is if a MCS can develop along the cold front. If it does, there is a risk of damaging winds given ample instability and shear. Thus the SPC`s slight risk across the area. - Dry Conditions Tuesday Night into Late Week Surface ridging and a dry moisture profile then return post cold- front Tuesday Night and continue through the rest of the work week. This looks to keep conditions dry. Highs fall into the 70s mid week as 850mb temps fall into the single digits before climbing back into the 80s by mid week. && .AVIATION /12Z TAFS THROUGH 12Z MONDAY/... Issued at 635 AM EDT Sun Jul 19 2026 As anticipated, visibilities have fallen to solidly MVFR as we approach daybreak due to smoke. GRR has already intermittenty reached IFR with the RRFS-Smoke (which has been the best performing guidance for this smoke outbreak) suggesting is likely to continue for the next few hours. Expectation is that visiblities will improve through the afternoon/evening favoring a return to VFR as smoke concentrations decrease. Expect winds aob 10 kts from the northeast, backing to westerly then southerly tonight. && .MARINE... Issued at 212 AM EDT Sun Jul 19 2026 May have to extend the southern portion of the Small Craft Advisory/Beach Hazards Statement for a few hours as waves at the South Haven spotter bouy have been slow to fall. Winds and waves then stay below hazardous levels during the day Sunday into the start of Monday. Winds then increase ahead of and behind a cold front later Monday into Tuesday. Thunderstorms are also possible across the waters Monday Night. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Air Quality Alert until midnight EDT tonight for MIZ037>040- 043>046-050>052-056>059-064>067-071>074. MARINE...None. && $$ DISCUSSION...Thomas AVIATION...Thomas MARINE...Thomas

NWS GRR Office Area Forecast Discussion