687 FXUS63 KGRR 131945 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 245 PM EST Tue Jan 13 2026 .KEY MESSAGES... - Snow Tonight Through Thursday Morning, Locally Heavy Near The Lakeshore - Accumulating Snow Likely Friday With Lake Enhanced System - Lake Effect Snow and Cold Continue Into The Weekend && .DISCUSSION... Issued at 237 PM EST Tue Jan 13 2026 - Snow Tonight Through Thursday Morning, Locally Heavy Near The Lakeshore The arrival of an arctic front after 06z tonight will cause a significant change in conditions by Wednesday morning. The setup will be favorable for snow squalls along the front with a brief burst of heavier snow, enhanced winds, and flash freezing of any roads that remain wet. Given the light snow amounts and progressive nature of this portion of the event, there is not enough to warrant headlines for this situation. Particularly with the bulk of the impacts occuring before the morning commute, this situation may be best suited for a Special Weather Statement. The front should clear the area by 6/7 am. Given the robust cold pool aloft with delta-Ts near 20C, lake effect will ramp up quickly post arctic frontal passage. Inversion heights in the afternoon Wednesday climb north of 10kft given the favorable instability, and BUFKIT progs show a very favorable environment with solid lift in the DGZ. Given the north-northwesterly flow regime the greatest impacts will be in the Mason, Oceana, northern Muskegon, western Allegan, and western Van Buren counties. The eastern shift noted yesterday in guidance continues with a strong signal among hi-res guidance for one or several heavier bands to develop across Southwest Michigan. Advisory level snow of 3-7 inches is likely, and if a band can become stationary, localized higher amounts will become likely. Will issue an advisory for these counties for now, but a warning may be needed in later updates if confidence increases in a stationary band developing and where it would develop. Gusty will may further cause travel impacts across this area with periods of blowing snow/reduced visibility. The rest of West Michigan is likely to see 1-3 inches of snow. The arrival of shortwave ridging Wednesday Night will lead to lake effect slowly winding down into Thursday morning. We`ll then see a short break for the day Thursday. - Accumulating Snow Likely Friday With Lake Enhanced System The break Thursday is short lived with the arrival of a potent shortwave and associated low pressure system Thursday Night into early Friday morning. Southwest flow with favorable over-lake instability will result in lake enhanced snow across West Michigan starting early Friday morning and continuing through the day. Snow is likely areawide with LREF ensemble mean QPF from 0.1" near US127 to 0.3" west of US131. Several inches of accumulating snow are possible, especially near and west of US131. Amounts will need to be fine-tuned over the next several days. - Lake Effect Snow and Cold Continue Into The Weekend The trough that will center over the eastern CONUS persists over the area into mid next week. Very cold air aloft associated with this will support continued lake effect potential. This pattern fits the classic "Hudson Bay Low" setup with several reinforcing shortwaves providing bursts of heavier lake effect through the weekend and into early next week. These frequent shortwaves and associated clippers will re-orient low-level winds making it difficult to pin down amounts at this range. The greatest potential for travel impacts will be near and west of US131 where the greatest lake enhancement will be. Accumulation over several days will quickly add up through early next week, in addition to persistent cold. Highs early next week may not make it out of the teens. && .AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/... Issued at 1233 PM EST Tue Jan 13 2026 Visible satellite imagery shows clearing moving across the terminals. VFR expected through the afternoon. A strong cold front will move through after midnight tonight and snow showers will develop along the frontal boundary. Cigs/vsbys will fall in conjunction with fropa. Expect snow showers in it`s wake. && .MARINE... Issued at 237 PM EST Tue Jan 13 2026 A Small Craft Advisory remains in effect this afternoon with wind gusts of 25-30 knots being seen at many of our lakeshore observation platforms. A Gale Warning goes into effect late tonight with wind gusts to 40 knots likely across the nearshore waters along with moderate freezing spray. Winds subside below gales early Thursday morning with conditions hazardous to small craft likely continuing into the weekend. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Winter Weather Advisory from 4 AM Wednesday to 7 AM EST Thursday for MIZ037-043-050-064-071. MARINE...Small Craft Advisory until 4 AM EST Wednesday for LMZ844>849. Gale Warning from 4 AM Wednesday to 1 AM EST Thursday for LMZ844>849. && $$ DISCUSSION...Thomas AVIATION...04 MARINE...Thomas

NWS GRR Office Area Forecast Discussion