textproduct: Grand Rapids

KEY MESSAGES

- Snow Returns Saturday into Sunday

- Mild Break Monday into Tuesday

- Falling Temps Wednesday, Wintry End to Week

DISCUSSION

Issued at 315 PM EST Fri Jan 9 2026

- Snow Returns Saturday into Sunday

An upper low is forecast to impact the Great Lakes Saturday into early Sunday with cooling temperatures aloft allowing for some snow production to occur. The upper low will be in the process of deepening on Saturday, with weak surface low development over Lower Michigan Saturday afternoon and some signal for lake aggregate troughing over Lake Huron to aid the cause as the low tracks overhead.

1000-700mb wind streamlines via the NAM12 and RAP13 indicate low level southwest flow is favored from 12z-18z Sat, then W to NW flow after that. Initially this will be a synoptic snow, likely wet to start. Precipitation begins Saturday morning as either a rain/snow mix or, more likely near and north of I-96, just snow. Air temperatures and road surface temperatures in the low to mid 30s to begin the event (likely starting in the 7am-9am timeframe on Saturday) will probably aid in some initial melting of what falls on the ground, thus 100% snow accumulation efficiency is unlikely initially. Cobb SLRs early on are between 5:1 to 10:1, especially when looking at the 12z HRRR and GFS. Therefore, this snow is likely to be on the wetter side of normal during the morning to early afternoon hours Saturday.

As low level flow shifts more WNW to NW Saturday evening into Saturday night and cold air advection aloft is underway, the lake enhanced component begins, transitioning to lake effect. SLRs will be higher during this time frame. Moisture depth and omegas look good for this period with 1000-700mb lift on the order of 3-6 ubar/s with high RH. NAM12 lift within the DGZ looks locally significant across our lakeshore counties from 03z Sun through 15z Sun. Bufkit soundings reveal deep moisture in place during this time. The current expectation is for the region along and north of a Muskegon to Big Rapids line to have the highest probability of 4" or greater, where odds are as high as 75%. South of this region, areas are unlikely to receive 4" or greater but will still get some accumulating snow. As a result, have decided to issue a Winter Weather Advisory from Muskegon to the north and northeast for the expectation of 3"-5" of total snow from Saturday morning through Sunday morning, locally 6" or greater possible. Areas south and east of the Advisory should top out in the 1"-3" range with locally 4" possible.

- Milder Monday into Tuesday

Upper heights build on Monday with 850mb WAA as temperatures at that level are favored to get above 0C. Highs should top out in the mid to upper 30s each day. However, upper troughing will be in the process of reclaiming the pattern across the Great Lakes on Tuesday and rain showers are in the forecast Tuesday morning and afternoon as a weak surface cold front moves through.

- Falling Temps Wednesday, Wintry End to Week

The primary cold front that ushers in colder temperatures is favored by ensemble guidance to move through sometime Wednesday. This looks to be a pretty sharp boundary that moves through with mid 30s ahead of it and teens to around 20 behind it. NBM washes out the temperature gradient signal at this range, but realistically this may be a case where temperatures drop 10 to 20 degrees in a few hours. Given a sharp upper trough moving in and a tight low level thermal gradient along and behind the front conditions may be conducive for rain showers quickly changing to snow showers and possibly heavier bursts of snow as the front moves through.

Ensemble guidance favors a more typical mid January setup by the end of next week into the weekend with some deeper upper troughing settling in and likely periods of lake enhanced or lake effect snowfall.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 650 PM EST Fri Jan 9 2026

A restriction filled TAF period will continue through tomorrow. Northwest flow continues but has slackened. MVFR cigs will continue with a drop to IFR towards morning. There remains a chance for FZRA/FZDZ between 07Z and 13Z before precipitation slowly transitions to snow. Wet heavy snow which will allow for a rain snow mix will bring periods of IFR cigs and vsbys at times through 00Z Sunday. Between 16Z and 23Z Periods of LIFR cigs and vsbys are possible in heaviest snow showers, especially if the snow is melting and if there is any RASN mix lingering. These conditions will affect all TAF sites west to east. Another round of snow due to lake effect will set up tomorrow night.

MARINE

Issued at 315 PM EST Fri Jan 9 2026

The Gale Warning will be ending this evening as the worst of the winds are over, but another gale event is possible by Sunday morning. Will allow current headlines to expire before going into another potential set for late in the weekend as strong NW flow develops between 06z-12z Sunday.

GRR WATCHES/WARNINGS/ADVISORIES

MI...Winter Weather Advisory from 7 AM Saturday to 1 PM EST Sunday for MIZ037>039-043>045-050. MARINE...Gale Warning until 7 PM EST this evening for LMZ844>849.