844 FXUS63 KGRR 092302 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 702 PM EDT Thu Apr 9 2026 .KEY MESSAGES... - Showers and isolated thunder tonight - Much warmer this weekend into next week/ showers and storms possible && .DISCUSSION... Issued at 128 AM EDT Thu Apr 9 2026 - Showers and isolated thunder tonight Skies have cleared across most of the cwa early this afternoon. Observations reveal a warm frontal boundary near I-94. South of the front, dewpoints are in the mid 40s while lower to mid 30s dewpoints were noted north of the boundary. This boundary will slowly move north tonight as low pressure over the central Plains moves east. H8 dewpoints increase to around 7c along the frontal boundary by 06z. Cams show convection developing along the boundary near the MI/IN border around 00z and slowly lifting north, only to be overtaken around midnight by convection streaming northeast with the wave from the Plains. Instability is limited with MUCAPE only a couple hundred j/kg, but the most likely location of thunderstorms would be south of I-96 tonight; severe storms are not expected. - Much warmer this weekend into next week/ showers and storms possible High pressure will build into the state Friday afternoon followed by upper ridging Friday night. H8 temperatures will begin climbing Saturday going from 0c Saturday morning to 16c Monday morning. Highs in the mid 70s Sunday and Monday will rise to the mid to upper 70s by Tuesday before dropping to the 60s and 70s Wednesday and Thursday. With the warmer weather though, comes higher dewpoints and increasing chances of thunderstorms. While we have thunder chances Sunday through Tuesday, chances of severe storms climb Tuesday as a frontal boundary is progd to be draped over the cwa and short waves will be riding northeastward on the periphery of the ridge. && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 702 PM EDT Thu Apr 9 2026 Widespread VFR conditions at present are expected to deteriorate through the night. First, showers are expected to develop off of a front across the Michigan/Indiana border impacting all terminals except MKG late this evening into Friday morning. This shower activity is overtaken by widespread rainfall beginning late tonight from west to east. Conditions will deteriorate to MVFR than IFR as this activity moves through. Cannot rule out isolated TSRA, mainly in the leading shower activity at AZO/BTL/JXN but confidence is to low to warrant any TAF mention. Ceilings will slowly improve as the rain exits late Friday morning into the afternoon, with most if not all sites reaching VFR by 00z Saturday. Expect winds to become light and variable overnight, increasing to around 10 knots from the northwest Friday. && .MARINE... Issued at 128 PM EDT Thu Apr 9 2026 The small craft advisory and gale warning were canceled earlier this morning. Wind and waves will not be hazardous to small craft through Saturday as waves of low pressure will move across the region. However, as the high drifts east Saturday night, south winds will increase and a small craft advisory will likely be needed. && .HYDROLOGY... Issued at 128 PM EDT Thu Apr 9 2026 Six river flood warnings remain on the Grand River as the crest works downstream toward Robinson Township. The flood warning for the Grand River at Grand Rapids was canceled earlier this morning. Additional rainfall tonight from a third to half inch is expected across the Grand basin with lesser amounts over the Muskegon basin. This amount of rainfall will probably not send the river back to flood stage but instead slow the rate of fall. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...04 AVIATION...Thomas MARINE...04 HYDROLOGY...04

NWS GRR Office Area Forecast Discussion