925
FXUS63 KGRR 181730
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
1230 PM EST Sun Jan 18 2026
.KEY MESSAGES...
- Snow, Blowing Snow, and Whiteouts Tonight into Monday
- Multiple Snow Events Possible Mid to Late Week
&&
.DISCUSSION...
Issued at 345 AM EST Sun Jan 18 2026
- Snow, Blowing Snow, and Whiteouts Tonight into Monday
A hazardous travel period sets up later this evening and lasts into
Monday as lake enhanced snow and some significant blowing and
drifting snow develops particularly near and west of US 131. Prior
to this, we still have some leftover snow showers and localized
accums to deal with early this morning mainly from Muskegon to the
north. This activity will gradually subside. Not much has changed
with previous forecast reasoning regarding the setup this evening
into Monday. An Arctic front arrives tonight as upper heights fall
and lake aggregate troughing and surface low development occurs
across Lakes Superior and Huron. As the Arctic front approaches, SW
flow lake enhancement develops in the 21z-00z time frame this
evening. Nam12 is showing strong omegas in the DGZ from BIV to GRR
and MKG and points northward this evening and early tonight. The SW
flow shifts westerly 03z-09z and then WNW to NW after that. Expect
lake effect bands to orient themselves accordingly.
The worst travel conditions look to occur from very early Monday
morning through Monday afternoon as boundary layer winds increase
and surface gusts reach 30-40 mph with some gusts of 40-50 mph along
the immediate lakeshore. This occurs with fairly prolific lake
effect snow coverage across the region. 00z WPC guidance gives areas
near and west of US 131 0.25"-0.50" through Monday evening with snow
ratios of 17:1 to 20:1. This will yield 4"-8" of snow during the
bulk of the event with some additional light accums Monday night
into Tuesday. Combine this with gusty winds and blowing/drifting
snow will be problematic. Particularly hazardous conditions are
expected to develop along N/S roads like US 31 and US 131 where
whiteouts are expected at times with potentially disorienting travel
conditions with loss of visibility. 00z HREF guidance is indicating
a 50% probability for blizzard conditions to develop along and west
of US 131. While this certainly could be true at times in open
areas, we historically have a very difficult time sustaining true
blizzard conditions solely from a lake effect event. As such, we are
not considering a Blizzard Warning at this point but will go ahead
with an upgrade to a Winter Storm Warning for the existing Watch
area plus some additional counties based on a combination of
accumulating snow, strong winds with blowing/drifting snow, and
hazardous travel. A Winter Weather Advisory will be issued further
inland as amounts will be lower but travel impacts will still occur.
Further eastward expansion of headlines may occur with future
forecast updates.
Snow intensity is expected to decrease late Monday into Monday night
as inversion heights decrease, though light accumulations and poor
visibility are still likely to occur with snow production continuing
above the DGZ (at temps colder than -18C). The wind factor does drop
off, though some travel impacts are likely to continue into Tuesday
morning. As such, have extended headlines into early Tuesday to
cover this threat. As for wind chills, still looking likely that
most areas will get into the -5 to -15 range Monday into Tuesday
with a possibility that areas inland may dip colder than -15.
- Multiple Snow Events Possible Mid to Late Week; More Cold Coming
A very active winter pattern continues mid to late week with
potentially multiple impactful snow events with hazardous travel
conditions possible at times. The Wednesday through Friday period
may feature a couple of lake enhanced snow events with some gusty
winds as well given a few pronounced deep troughs that swing
through providing some synoptic lift over the lake. It`s not
impossible that lake effect snow showers may be nearly continuous
during this period.
ECE guidance for multiple cycles has been showing even colder air
arriving next weekend compared to what`s coming Monday into
Tuesday. Highs may not even get out of the single digits
potentially. This may be a reflection of the increasingly negative
Arctic Oscillation developing.
&&
.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1230 PM EST Sun Jan 18 2026
Bottom line up front... significant impacts to aviation are
expected over the next 24 hours as a winter storm crosses the area,
with the worst conditions at MKG and GRR.
Light snow showers continue through the afternoon with
intermittent drops to IFR possible over the next few hours at
MKG/GRR. Deteriorating conditions begin after 21z at MKG/GRR with
light snow expected and moderate to heavy snow possible as lake
enhanced snow increases in coverage and intensity. After 00z snow
expands across the rest of the terminals with moderate to heavy
snow at MKG/GRR and light to moderate snow at the other terminals.
An arctic front crossing the terminals after 11z will result in
further deterioration as winds increase and BLSN develops.
Visibilities could be significantly impacted, with widespread
LIFR conditions. Periods of near blizzard conditions are likely at
MKG after 11z, and potentially at the other terminals as well
(with GRR having the best chance of the other terminals). Expect
southwest winds today to become westerly Monday with gusts of
30-35 knots during the day on Monday.
&&
.MARINE...
Issued at 345 AM EST Sun Jan 18 2026
Gales are expected along with freezing spray Monday into Tuesday.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Storm Warning from 4 PM this afternoon to 7 AM EST
Tuesday for MIZ037-038-043-044-050-056-057-064-071.
Winter Weather Advisory from 4 PM this afternoon to 7 AM EST
Tuesday for MIZ039-040-045-051-058-065-072.
MARINE...Small Craft Advisory until 1 AM EST Monday for LMZ844>849.
Gale Warning from 1 AM to 7 PM EST Monday for LMZ844>849.
Heavy Freezing Spray Warning from 1 AM Monday to 7 AM EST
Tuesday for LMZ844>849.
&&
$$
DISCUSSION...Hoving
AVIATION...Thomas
MARINE...Hoving
NWS GRR Office Area Forecast Discussion
