464 FXUS63 KGRR 201730 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 130 PM EDT Sat Jun 20 2026 .KEY MESSAGES... - Chance of showers through Northeast Michigan late today - Showers Late Sunday into Monday - Showers and storms possible Midweek && .DISCUSSION... Issued at 1200 PM EDT Sat Jun 20 2026 - Chance of showers through Northeast Michigan late today A Weak trough continues to filter through the region today. While there is not a lot of instability overall, A PV anomaly should allow for enough through northeastern and north central MI for isolated storms late this afternoon. The northwesterly flow will keep temperatures cool with gusty winds upwards of 25 mph. - Showers Late Sunday into Monday So the upper level low that has been in discussion for the last few days continues to waffle based on the upper level pattern. Some runs have shifted the trough further south, NAEFS specific humidity and the EC ensembles continue has the upper level moisture further northward in Lower Michigan. Timing remains a Sunday evening into Monday morning event. ` Areas along and south of the I 96 corridor should receive some rainfall. The question remains where the highest axis of precipitation will be. The best moisture should remain in IN and Ohio. QPF should range around a half an inch along I 96 down to 1 to 1.5 inches along I 94 southward. - Showers and storms possible Midweek The forecast remains fairly consistent ahead. Upper level low remains on track to drop southward across the Upper Midwest with the low expected to track through Michigan Thursday. So mid week showers and storms are possible with Highs trending closer to normal with slightly more warm air advection. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 128 PM EDT Sat Jun 20 2026 Diurnal cu will dissipate around sunset leaving mostly clear skies overnight. Some patchy fog is possible around sunrise however. A mid cloud deck will advect over the terminals Sunday morning as low pressure approaches from the west. && .MARINE... Issued at 1200 PM EDT Sat Jun 20 2026 Fairly tranquil conditions into Sunday then winds and waves will increase Sunday night as low pressure passes just south of Lake Michigan. A SCA may be needed for Monday. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Ceru AVIATION...04 MARINE...Ceru

NWS GRR Office Area Forecast Discussion