925 FXUS63 KGRR 251119 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 719 AM EDT Sat Apr 25 2026 .KEY MESSAGES... - Quiet weather conditions today through Monday morning - Showers and thunderstorms expected Monday night - Mainly dry and cooler for the remainder of the work week && .DISCUSSION... Issued at 350 AM EDT Sat Apr 25 2026 - Quiet weather conditions today through Monday morning Rain showers have moved east of the Lower Peninsula this morning as a low treks southeast away from the Great Lakes. A northerly push of wind in the wake of the low is bringing in low clouds early this morning. We expect the clouds to peak in coverage this morning and then gradually try to erode from west to east during the midday and afternoon. HRRR soundings would speak to a more pessimistic forecast though as a stout subsidence inversion is seen with moisture trapped below. Would not be surprised to hang on to some clouds through the entire day, especially towards JXN. Dry weather is expected tonight through the rest of the weekend with high pressure in control of the area weather at the surface. Precipitation with our next system looks to hold off through much of Monday. Temperatures will be near normal for this time of year. - Showers and thunderstorms expected Monday night Showers and storms are likely Monday night with some shower activity lingering into Tuesday morning. The main focus for Monday night is the chance for severe weather. The models lift a potent looking upper shortwave into the Great Lakes region with diffluence seen at 500mb indicative of the strength of the system. Down at the surface a deepening low will lift through Wisconsin which will bring a 50 knot low level jet into the area, which is quite strong even by April standards. Speeds in the mid levels are on the order of 60-70 knots. So, suffice it to say we will have plenty of deep layer shear in place...near 50 knots. The question remains how much instability we will have to work with as the activity will be coming in during the night. Models suggest we still may have 1,000 j/kg to work with. Given surface dew points rise to around 60F and PWAT values increase to around 1.5 inches, our feeling is the instability in the GFS and ECMWF is probably underdone. The NAM`s 1,000 to 2,000 j/kg looks more likely. Given the CAPE / Shear parameter space we feel severe weather is certainly possible. SPC`s day 3 outlook has us in a marginal at this point in the southwest corner of the CWA. Could see that expanding in coverage and possibly being bumped up a category as we draw closer to Monday night. Given the moisture and lift in play, we are looking at a locally heavy rain threat as well. Half inch to one inch amounts look reasonable. - Mainly dry and cooler for the remainder of the work week We remain in broad upper troughing through the remainder of the work week. Given a colder airmass and late April sun angles we probably can`t rule out some diurnal showers each afternoon, but the bulk of the time most areas will be dry from Tuesday afternoon through Friday. Partly cloudy skies and temperatures sliding back into the 50s for highs. && .AVIATION /12Z TAFS THROUGH 12Z SUNDAY/... Issued at 720 AM EDT Sat Apr 25 2026 Low clouds have spread over much of Southwest Lower Michigan as of 12z. Ceilings vary a few hundred feet either side of 1,000 feet making both IFR and MVFR ceilings present. Through the course of the morning we expect ceilings to scatter out across Western Lower Michigan. Through the center of the state, LAN and JXN, we expect the lower ceilings to persist into the afternoon. There is a chance that the lower ceiling remain in place even into the evening at JXN. Tonight VFR weather is expected at all sites. && .MARINE... Issued at 350 AM EDT Sat Apr 25 2026 Low pressure will pull away to the east of Lower Michigan today resulting in north winds over Lake Michigan. 10-20 knot winds are likely with a chance for slightly higher when looking at the mid lake buoy BUFKIT site. We should be looking at 2-4 foot waves today with the highest waves occurring from Grand Haven to the south. High pressure settles in for the rest of the weekend with winds going off shore given our base of the high location. Winds and waves will stay below Advisory levels tonight and Sunday. A strong low will lift northward across Wisconsin on Monday resulting in an increase in winds. Small Craft Advisory conditions are likely Sunday night into Monday. We may touch gale force winds Monday night. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...None. && $$ DISCUSSION...Duke AVIATION...Duke MARINE...Duke

NWS GRR Office Area Forecast Discussion