979 FXUS63 KGRR 161153 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 653 AM EST Fri Jan 16 2026 .KEY MESSAGES... - Accumulating Snow Through Tonight - Periods of Heavy Lake Effect Snow This Weekend - Bitterly Cold Monday and Tuesday with Snow Showers && .DISCUSSION... Issued at 330 AM EST Fri Jan 16 2026 - Accumulating Snow Through Tonight Well defined upper troughing moves in today with periods of synoptic lift as a surface low develops over northern Lake Michigan. Low level trajectories over the lake start off as S/SW and as such there will be some lake enhanced component to the synoptic snow today mainly from Holland to the north initially through early afternoon and then stretching inland mid afternoon through tonight as flow shifts westerly, though delta Ts are not great until we head into tonight. Lake induced CAPE via HRRR guidance shows 100-200 J/kg starting around 21z and that could lead to some heavier bursts of snow moving off the lake this afternoon and evening. 1000-700mb RH of 90-95% and associated lift of 5-10 ubar/s looks pretty solid for this event, with perhaps a limiting factor on higher SLRs materializing being occasionally lower RH and lift within the DGZ itself at times and greater lift occurring below the DGZ. Cobb SLRs are averaging 10:1-12:1 due to more of a riming factor which is a bit lower than WPC guidance at 14:1-15:1. Nevertheless, snow accumulations are expected and impacts to travel will be greatest across the Advisory counties today and tonight. Outside of the Advisory, travel impacts are still likely especially from Montcalm to Isabella/Clare and points west but just about everyone will get some accumulation today and tonight, so allow extra time to reach your destinations. Total accumulations through Saturday morning of 1"-3" (locally higher) are expected along the US 127 corridor, then increasing as you head west toward US 131 (2"-5") and finally the lakeshore with the greatest amounts across Ottawa/Muskegon/Oceana/Mason Counties where 4"-7" is expected. - Periods of Heavy Lake Effect Snow This Weekend While it may be snowing in general most of the time near/west of US 131 this weekend, the snow may get heavy later Saturday afternoon into Saturday night and then again Sunday evening through Sunday night. There are a few reasons for this. Upper vort lobes swing through at those times, especially Sunday night as an Arctic front arrives which will usher in some bitterly cold air. Surface convergence is noted via the RAP13 and NAM12 models to set up along and west of a LWA to LAN line during those periods, and with lift and saturation through the DGZ occurring during both windows. Low level frontogenesis can occur during times when truly Arctic air wraps around the southern end of the lake and southwesterly surface winds converge with westerly near/north of the LWA-LAN line. This could lead to some periods of significant snow, though exact placement and magnitude are still a bit in question. Current NBM QPF is likely underdoing the magnitude of this setup, and once high res models better define where the bands will develop we will get a better idea of amounts and if additional winter headlines are warranted. The Sunday evening/night snow event looks particularly impactful with the NAM12 indicating strong lift (10-15 ubar/s) in the DGZ near and west of US 131 for at least a 12 hour period. Blowing and drifting snow is expected as well with wind gusts of 25- 35 mph. Travel conditions look significantly impacted across our lakeshore region and into US 131. - Bitterly Cold Monday and Tuesday with Snow Showers The well advertised Arctic air arrives Monday morning and lasts through Tuesday as -25C air moves in at 850mb. High temperatures Monday will occur immediately after midnight, technically in the mid teens, but will be falling into the single digits during the day as wind gusts of 35-45 mph will lead to unpleasant wind chill readings of -10 to -20. As the DGZ crashes to the ground the snow production process will occur at temperatures colder than -18C and as such the snow will consist of columns and plates as opposed to the stackable dendrites. Nevertheless, while this type of snow doesn`t accumulate as significantly, it is more effective at impacting visibilities and when combined with strong wind gusts on Monday, travel conditions look poor. Wind chill readings into Tuesday morning may also bottom out in the -10 to -20 range. As such, Cold Weather Advisories may be needed Monday into Tuesday. && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 644 AM EST Fri Jan 16 2026 Light snow moving across eastern WI and Lake Michigan has produced visibilities of 1-2sm and that is generally expected here as the snow moves in. There is a risk for 3/4sm at MKG and GRR this morning into early afternoon. Expect a decrease in snow shower coverage and intensity late afternoon and evening but occasional snow showers redevelop later this evening into tonight with some visibility reductions. && .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...Hoving AVIATION...Hoving

NWS GRR Office Area Forecast Discussion