FXUS63 KGRR 021740 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 140 PM EDT Wed Jul 2 2025 .KEY MESSAGES... - Scattered Showers/Storms Possible Today through Friday - A Better Chance for Showers/Storms Saturday night and Sunday - A Warmup into Saturday then a Slight Cooling Next Week && .DISCUSSION... Issued at 348 AM EDT Wed Jul 2 2025 - Scattered Showers/Storms Possible Today through Friday Several chances for showers and storms exist today through Friday with the first occurring this afternoon and evening. A weak surface boundary will sag south into the area this afternoon. That front combined with some convergence in the interior portion of the state will drive some scattered shower and thunderstorm activity. The eastern CWA towards Highway 127 has the best chance this afternoon and then Central and Western Lower get into the act in the late afternoon and evening. A shortwave will be working through the flow aloft so there will be some support for convection today. We are in the SPC marginal today, but any chance at severe looks pretty low. An outside chance at some localized stronger winds would be the main threat (50-60mph). Some of the activity will last until after sunset before fading. The boundary remains in the area on Thursday albeit very weak. It will be a location of some convergence however and with an unstable airmass not out of the realm that we may see some scattered showers and storms. The HREF is focusing on areas from Grand Rapids south and east through Battle Creek, Lansing and Jackson. We are in a day two Marginal as well, but again severe threat looks limited. We have gone dry for the Fourth, but would not be surprised to see some scattered showers and storms developing along a warm front. Agree with the previous discussion that the rising heights may put a lid on anything that tries to develop and actually that is what we are leaning on at this point. - A Better Chance for Showers/Storms Saturday night and Sunday A cold front pushes into the area Saturday night and progresses through on Sunday. We have 40-60 pct chances for rain in the forecast with this frontal passage. This will not be a washout by any means, but there will be some rain around. - A Warmup into Saturday then a Slight Cooling Next Week A steady warm up will continue into Friday and Saturday followed by a cooling back to normal into early next week. 850mb temperatures peak Saturday into Saturday night around +20C. This will result in highs on Saturday into the 90s. We will be well into the 80s to around 90 today through Friday, so summer like weather is certainly in the forecast for the Fourth weekend. Early next week we cool back into the lower teens C at 850mb which has our forecast highs around normals...near 80 to the lower 80s. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 135 PM EDT Wed Jul 2 2025 Diurnal cu will dissipate around sunset leaving mostly clear skies. However, a weak upper trough moving across the region may produce a shower near LAN/JXN after 19z; a thunderstorm is also possible but just mentioned a chance of showers at those terminals. Radar shows a few showers developing along/east of US-127 currently and those are moving ESE. It's also possible that MKG could see a shower/storm around 06z from convection moving southeast from northeast Wisconsin and northern Lower, but models are less than clear on that signal. Otherwise, VFR expected through the period. && .MARINE... Issued at 135 PM EDT Wed Jul 2 2025 Waves will remain aob 2 feet through Friday before southwest winds increase Saturday. Waves will increase to 2-4/3-5 ft north of Whitehall Saturday afternoon and a small craft advisory may be needed then. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None.MARINE...None. && $$ DISCUSSION...Duke AVIATION...04 MARINE...04