455 FXUS63 KGRR 291746 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 146 PM EDT Wed Apr 29 2026 .KEY MESSAGES... - Scattered Showers Today and Thursday - Relative lull Friday through Saturday - More unsettled next week with higher chances for rain && .DISCUSSION... Issued at 308 AM EDT Wed Apr 29 2026 - Scattered Showers Today and Thursday We have now completed the pattern shift for the CONUS to that of strong ridging building along the western U.S. Coast, and an upper low closing off just north of the U.S./Canadian border border. What we have here is a return to the pattern from this past winter with the upper flow from the W/NW, now combined with the late April tendency for upper lows to cut off and a stronger sun angle. We will see chances for scattered showers each of the next couple of days We have a couple of decent upper short waves aimed at our area. These short waves are of decent strength, but do not have any good moisture to work with at this time. The best concentration of showers will be during the daylight hours, as the sun contributes to some diurnal instability. The thunder chances look low enough to leave out of the forecast at this time. - Relative lull Friday through Saturday We will keep the lower heights and cold pool aloft over the area for the foreseeable future. In the large picture, we see a blocking pattern taking shape in the for of an Omega and REX block. The Omega block is made up of lows over the Pacific and the upper midwest. This will continue the wave train rotating through, although they will not be as direct on our area, and should allow for mainly dry conditions friday and Saturday. We can not rule out a brief shower, but dry weather will dominate Thursday and Friday. Friday will be cool with highs possibly remaining in the 40s. One thing for Thursday and Friday is there may be a potential for each of these nights for some frost, or even a freeze. We will be watching for those, and issue headlines accordingly. - More unsettled next week with higher chances for rain We will become under better influence of the upper low early to mid week next week once again, with rain chances increasing accordingly. The upper low once again stays over our area, and becomes more favorable for diurnal shower activity once again. We will see the short waves move through once again beginning late Sunday, and going through mid week next week. These waves are expected to be a bit more favorable for rain for a couple of reasons. The first being the systems being a bit stronger in the flow, almost closing off as they approach Michigan. The second items is that with the systems being stronger, they will have better opportunity to tap moisture from the Gulf. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 142 PM EDT Wed Apr 29 2026 Light rain associated with an upper trough moving through the region will continue to fall this afternoon before ending late in the day. IFR cigs are expected overnight due to abundant low level moisture. Some improvement is expected Thursday morning as slightly drier air advects in from the west. && .MARINE... Issued at 308 AM EDT Wed Apr 29 2026 The potential for marine headlines over the next few days is on the lower side. Even though we will be in an unsettled weather pattern with many mini-lows/waves, the pressure gradient does not look strong enough at this time to require headlines.We will see periods where winds may get up to 20 knots, and corresponding waves at 2-3 feet, but nothing too strong at this time. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Freeze Warning from 2 AM to 9 AM EDT Thursday for MIZ038>040-045. Frost Advisory from 2 AM to 9 AM EDT Thursday for MIZ044-046-051- 052-057>059-065-066. MARINE...None. && $$ DISCUSSION...NJJ AVIATION...04 MARINE...NJJ

NWS GRR Office Area Forecast Discussion