034 FXUS63 KGRR 262355 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 755 PM EDT Thu Mar 26 2026 .KEY MESSAGES... - Showers & Chance of a Few Storms into This Evening - Colder Friday and Saturday with Some Snow Showers Possible - Rain Chances Increase Next Week && .DISCUSSION... Issued at 256 PM EDT Thu Mar 26 2026 - Showers & Chance of a Few Storms into This Evening Overall the severe weather threat is low for our area through this evening, but locations along and south of I-94 will need to be watched for a narrow window of time where some mainly elevated thunderstorms could develop, posing a hail risk. 12z HREF guidance indicates that surface based instability will exit the region by 21z, with MUCAPE exiting shortly thereafter. An assessment of 12z CAMs indicates there is little risk for any surface based convection developing in our region prior to FROPA. What may occur during the late afternoon and evening hours is some elevated convection near and south of I-94 with perhaps a hail threat continuing given 500-800 J/kg of MUCAPE, before this threat ends probably by 7pm-8pm. Elsewhere, showers will be progressing through the region this evening with a rumble of thunder possible near and south of I-96. - Colder Friday and Saturday with Some Snow Showers Possible Much colder air settles in Friday and Saturday with well below normal temperatures. Upper troughing moves through on Friday with some moisture and lift present within the DGZ mainly after dark Friday night, as shown in the 5k-10k foot layer (RH/lift) where the DGZ will largely be centered. Snow showers will be possible primarily during the 00z-12z Saturday time frame with a few tenths of an inch that may accumulate mainly near/north of I-96. Conditions dry out for Saturday. - Rain Chances Increase Next Week A typical late March / early April pattern takes shape next week. ECE/GEFS/CMC mean 500mb heights and vorticity continue to show a reorientation of upper ridging from the SW U.S. toward the SE U.S. by early in the week. This sets up a southwest flow regime over the Great Lakes with potential upper shortwave trajectories overhead. ECE mean PWAT values are shown to be 200% of normal at times. Deterministic guidance (ECWMF/GFS/GEM) suggests the potential for occasionally vigorous LLJ development into midweek. Surface warm frontal or stationary frontal development will be key to where storm development may occur, and hence the risk for heavy rainfall. Ensemble guidance shows spread on where potential frontal positioning may set up, but the general trend will be for increasing rain chances starting as early as Monday night with wet weather possibly into midweek. && .AVIATION /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 754 PM EDT Thu Mar 26 2026 A cold front has slipped south of the state as of 00Z. Ceilings have become highly variable with a trend though towards MVFR. We feel MVFR ceilings will become the dominant category as we move through the night. Rain should peel off to the east and come to an end in the 04Z to 06Z time frame. VFR weather is expected to prevail from around 12Z on Friday through the rest of the day. Winds will be north to northeast at 10-20 knots tonight. && .MARINE... Issued at 256 PM EDT Thu Mar 26 2026 Increasing northerly flow over Lake Michigan will build waves into the 4 to 7 foot range and hazardous conditions to small craft will persist into early Friday morning. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory until 6 AM EDT Friday for LMZ844>849. && $$ DISCUSSION...Hoving AVIATION...Duke MARINE...Hoving

NWS GRR Office Area Forecast Discussion