719 FXUS63 KGRR 130646 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 246 AM EDT Mon Jul 13 2026 .KEY MESSAGES... - Hot Temperatures through Wednesday - Rain Chances Return for Friday into the Weekend && .DISCUSSION... Issued at 246 AM EDT Mon Jul 13 2026 - Hot Temperatures through Wednesday High pressure will build over the area before the upper level ridge weakens Wednesday. Thunderstorms currently moving south into northern lower Michigan are anticipated to weaken as they move into a less favorable environment. Areas along and north of US-10 may see the remnants of these storms, otherwise dry conditions are expected. We`ll see temperatures in the low to mid 90s today with heat index values pretty close to air temperatures. Spots in Clare, Isabella, and Gratiot counties may see heat index values approach 100. Tuesday 925mb temperatures increase into the 27 to 30 C range. Based on sounding profiles this will result in high tempeatures around 96 to 100 degrees with the hottest temperatures in Clare, Isabella, and Gratiot counties. Dew points will also be higher tomorrow in the 60s to low 70s. This will result in heat index values in the 100 to 105 range. Locations along the US-127 corridor have the best potential to see heat index values of 105 or greater, therefore an Extreme Heat Watch is in effect for those locations. Wednesday areas along and south of I-96 have the best chance to see heat index values rise again into the 98 to 104 range. There will be some relief at night with lows in the upper 60s to low 70s, but these multiple days of hot temperatures will be dangerous to those outside and unable to cool off. Make sure to find air conditioning, avoid strenuous activities, wear light clothing, check on family members and neighbors, drink plenty of water, and watch for signs of heat exhaustion and heat stroke. - Rain Chances Return for Friday into the Weekend As mentioned, the upper level ridge is expected to weaken around Wednesday with northwest flow expected over the area. Within the northwest flow we`ll have to watch for shortwaves to track through the region which will bring chances for showers and thunderstorms. Overall confidence is not high at any one time for these chances. This is due to differences as seen in the cluster analysis of the strength of the overall ridge and trough. Depending on how the pattern sets up, we could see an active period of rain chances into next week. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 138 AM EDT Mon Jul 13 2026 VFR conditions continue with light westerly winds expected for Monday. Overall skies will be mostly clear, but some remnant clouds from thunderstorms to the north will track through Monday morning. Maybe briefly bring ceilings around 9,000 feet, otherwise ceiling will remain above 10,000 feet. && .MARINE... Issued at 246 AM EDT Mon Jul 13 2026 West to southwest winds develop today around 5 to 15 knots with waves of 0 to 2 feet. Similar conditions are expected Tuesday before winds shift to the northwest Tuesday night into Wednesday. Other than a stray shower near Ludington, dry conditions are expected through much of the week. && .CLIMATE... Issued at 246 AM EDT Mon Jul 13 2026 Here are the high temperature records for July 13, 14, and 15. Location July 13 July 14 July 15 Grand Rapids 108 (1936) 102 (1936) 95 (2013) Lansing 99 (1936) 101 (1936) 99 (1977) Muskegon 93 (1995) 94 (1995) 93 (1995) Kalamazoo 109 (1936) 108 (1936) 103 (1936) Battle Creek 103 (1936) 104 (1936) 100 (1977) Holland 99 (1936) 98 (1995) 98 (1932) && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Extreme Heat Watch from Tuesday afternoon through Tuesday evening for MIZ040-046-052-059-067-074. MARINE...None. && $$ DISCUSSION...RAH AVIATION...RAH MARINE...RAH CLIMATE...RAH

NWS GRR Office Area Forecast Discussion