683 FXUS63 KGRR 232315 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 715 PM EDT Sat May 23 2026 .KEY MESSAGES... - Showers and A Few Storms Sunday - Warmer With Low Precipitation Chances Early Next Week - Dry and Cool Late Next Week && .DISCUSSION... Issued at 214 PM EDT Sat May 23 2026 - Showers and A Few Storms Sunday Radar shows that ongoing showers continue to diminish this afternoon. A lull in precipitation is expected for the evening and overnight hours. Then, our next mid-level wave arrives driving a line of showers across the area. Forecast soundings show MUCAPE values of a few hundred J/kg which would be sufficient for some embedded thunderstorms. The other concern is for areas of fog development overnight given the high ambient moisture and light winds. The best signal is across the US-127 corridor where light north/northeasterly flow off of Huron may aid boundary layer moisture. - Warmer With Low Precipitation Chances Early Next Week We see large scale ridging move in early next week as an Omega Block pattern sets up across the Central CONUS. Rain chances are low given that this will force the polar jet north and east of the area. There are two chances worth mentioning, Monday and Wednesday, both with low chances. Monday will feature a low (less than 20 percent) chance of a shower or storm across our northeast CWA as a weak mid-level wave interacts with convergence off of Lake Huron with the ambient flow. The best chance will remain north and east of the area however. Wednesday will feature a backdoor cold front moving in from the north, a stationary front south of the area across the lower Ohio Valley, and a shortwave attempting to reach the area. Given these features don`t really overlap across the area, precipitation chances are low, maxing out at 30 percent across the I-94 corridor. 850mb temps also climb into the mid-teens early next week, allowing highs to climb well into the 80s. - Dry and Cool Late Next Week Once the back door cold front exits the area going into Thursday, an overall cooldown is expected. Some uncertainty exists in the placement of the polar jet and by extension the degree of the cooldown. However, confidence is higher in dry conditions given predominant surface and upper-level ridging and a drier ambient airmass. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 715 PM EDT Sat May 23 2026 Ceilings are holding on in most locations at or below 2,000 feet this evening, with some tendency for scattering possible over the next few hours. However, conditions will likely deteriorate again toward IFR ceilings or visibility later in the night as winds are light and lower atmospheric moisture is plentiful. Rain showers and a chance of thunderstorms will move through from west to east Sunday morning. Clearing to VFR is favored later in the day, from west to east. && .MARINE... Issued at 214 PM EDT Sat May 23 2026 A weaker pressure gradient and by extension lighter winds/more subdued waves is forecast over the next week. This means headlines are not expected through the rest of the Memorial Day weekend into early next week. Offshore flow continues through the rest of the day before coming back onshore going into Sunday. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Thomas AVIATION...CAS MARINE...Thomas

NWS GRR Office Area Forecast Discussion