849 FXUS63 KGRR 120548 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 148 AM EDT Sun Jul 12 2026 .KEY MESSAGES... - Hot and Dry Monday through Wednesday - Rain Chances Return End of Week && .DISCUSSION... Issued at 148 AM EDT Sun Jul 12 2026 - Hot and Dry Monday through Wednesday High pressure will build into the region today through Tuesday. A weak shortwave may bring a stray shower late tonight or Monday morning north of I-96, otherwise dry conditions are expected through midweek. As pressure heights increase so will temperatures. We`ll see high temperatures in the mid to upper 80s today increasing into the upper 80s to mid 90s Monday. 925 mb temperatures peak around 28 C Tuesday resulting in highs in the mid to upper 90s with some areas in central lower Michigan potentially hitting 100. Wednesday the upper level ridge begins to weaken overhead resulting in slightly lower temperatures in the low to mid 90s. The best chance for heat index values at or above 100 (Heat Advisory criteria) will be Tuesday. Long range ensemble members highlight areas east of US-131 with a 30 to 60 percent chance of heat index values greater than or equal to 100 on Tuesday. Temperatures are expected to improve overnight with lows in the 60s to around 70. - Rain Chances Return End of Week Northwest flow moves in for the second half of the week with lower pressure heights. Within the northwest flow shortwave troughs will move through bringing chances for rain and thunderstorms. At this time confidence is higher in the Thursday night into Friday timeframe with a 20 to 40 percent chance for showers and thunderstorms. There is variability in the overall atmospheric pattern into the following weekend resulting in continue chances for rain and thunderstorms. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 148 AM EDT Sun Jul 12 2026 VFR conditions are expected today with light easterly winds. A lake breeze is expected to develop this afternoon with winds shifting to the northwest at MKG around 17Z. && .MARINE... Issued at 148 AM EDT Sun Jul 12 2026 Offshore winds are expected early today before the lake breeze develops this afternoon. Winds then become more westerly for Monday and Tuesday then turn more northwesterly Wednesday. Winds may briefly approach Small Craft Advisory levels Wednesday afternoon. Otherwise winds and waves are expected to remain below Small Craft Advisory and Beach Hazard Statement levels. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...RAH AVIATION...RAH MARINE...RAH

NWS GRR Office Area Forecast Discussion