874 FXUS63 KGRR 160437 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 1137 PM EST Thu Jan 15 2026 .KEY MESSAGES... - Southwest Flow Lake Effect Snow Tonight and Friday - Lake Effect Plus Arctic Blast Next Week && .DISCUSSION... Issued at 248 PM EST Thu Jan 15 2026 - Southwest Flow Lake Effect Snow Tonight and Friday Classic southwest flow lake effect snow set up for tonight through Friday with clipper surface low tracking across northern Lower Michigan and surface ridge axis to the southeast over the Ohio Valley. A vorticity maximum at the base of the shortwave trough axis will aid in providing lift as inversion heights increase from around 5 kft this evening to over 10 kft by noon on Friday. Expect bands of heavy snow to be aligned from near South Haven to the northeast and clipping western Kent and Newaygo Counties. The flow goes more westerly Friday afternoon as the shortwave trough axis moves east and the heavier snow should taper off as inversion heights come down below 10 kft. - Lake Effect Plus Arctic Blast Next Week A longwave trough will persist through the weekend and LES will continue to flare up at times as weak, quick moving shortwave troughs rotate through. It will be cold through the week with 850 mb temps bottoming out around minus 25C on Monday and Tuesday. Right now our forecast apparent temperatures are only minus 10F during this time, but relatively unmodified arctic air coming around the southern part of Lake Michigan could penetrate into the southern half of our forecast area and deliver below zero air temperatures and wind chill/apparent temperatures of minus 20F or lower. This is something we will focus on the next few days to see if cold weather headlines will be necessary. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1137 PM EST Thu Jan 15 2026 A clipper system will move through the TAF sites over the next 24 hours. It is currently diving southeast out of MN. Snow associated with the clipper will move through all of the TAF sites late tonight and especially into the day on Friday. Lake enhanced snows will affect MKG and GRR the most. By 12z-13z MVFR ceilings will have spread into all of the TAF sites with MKG potentially dipping to near IFR. Snow will spread into MKG around 08z and into the other TAF sites between 10z and 14z. The most widespread snow and the worst of the conditions will occur between 15z and 21z as visibilities dip to IFR and below and ceilings bottom out around 1,000 feet. The snow will persist for the remainder of the TAF period, from 21z through 06z, with visibilities improving slightly. Ceilings will likely remain between 1,000 and 2,000 feet. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Winter Weather Advisory until 7 AM EST Saturday for MIZ037-038- 043-044-050-056-057-064-071. MARINE...Small Craft Advisory until 5 AM EST Monday for LMZ844>849. && $$ DISCUSSION...Ostuno AVIATION...Duke

NWS GRR Office Area Forecast Discussion