458
FXUS63 KGRR 061138
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
638 AM EST Sat Dec 6 2025

.KEY MESSAGES...

- Chance of freezing drizzle remains this morning south

- Snow amounts for tonight-Sunday trending a little higher

- Multiple chances for some accumulating snow next week

&&

.DISCUSSION...
Issued at 324 AM EST Sat Dec 6 2025

- Chance of freezing drizzle remains this morning south

Latest radar imagery this morning shows the more widespread light
snow earlier is steadily tapering off. What is left is an arc of
light snow extending from Mt. Pleasant, to Holland, to near Battle
Creek. This area is progressing east, and losing its steam likely as
it moves away from the warmer and moist air from Lake Michigan.

As this area of better echoes moves east, it will be when this moves
out that there will be a short window of opportunity for some
freezing drizzle. This will be the result of the loss of deeper
moisture, where the DGZ may become unsaturated briefly before all
precipitation ends, or flurries develop as cooler air moves in and
the DGZ becomes saturated. Thankfully this should not last long if
it occurs, and will be happening during a lower impact period as
compared to rush hour during the weekdays. So far, there has not
been anything reported upstream over Wisconsin. We will monitor this
situation for any extra messaging that might be needed.

The rest of the day should be mainly quiet. There may be some
flurries with the moisture layer in the dgz for the rest of the day.
No accumulations are expected through this evening.

- Snow amounts for tonight-Sunday trending a little higher

What looked like yesterday as another light accumulation of snow for
the lakeshore later tonight and Sunday morning, has now evolved to
looking a little more favorable for more of the forecast area to see
some accumulations, albeit light still.

We are still watching the next short wave coming at the area from
the WNW over British Columbia early this morning. What has become
more apparent is upper jet forcing, and even some possible coupling
of a departing jet to our ENE and the incoming jet streak.

This added forcing is helping to bump snow totals up a bit for this
next system, and to bring it in a little earlier. The lakeshore is
still looking like 1-2 inches, but now much of the forecast area is
looking at that amount, and maybe even a tad higher across the
southern half of the area where the forcing from the coupling jets
looks to be maximized. For the most part right now, it looks like we
will not need headlines. If amounts trend much higher, we may need
to consider some headlines down south.

- Multiple chances for some accumulating snow next week

We will see a fairly decent break in the snow potential from Sunday
afternoon through Monday evening. The next wave in the series misses
us to the south, and takes the associated forcing with it. The air
is cold enough for lake effect, but the flow will be offshore
initially on Sunday ahead of the incoming sfc ridge. Then, the flow
becomes from the SSW on Monday, and may clip Little and Big Sable
points with a few snow showers on Monday.

We will see enough warm air advection take place by the overnight
hours Monday night for light snow to break out for much of the area.
This is out ahead of a short wave heading straight for the area, and
associated sfc low riding along the U.S./Canadian border. This will
be another system in which the NW portion of the area will see the
best accumulations with the flow from the SW off of the warmer lake
in addition to the moisture boost. Those areas could see up to 4
inches or so, where the rest of the area would see 2 inches or less.

After a brief break on Tuesday in the wake of the low passing NE of
the area, the next system will bring in snow beginning Tuesday
evening and lasting into Wednesday morning. Right now, the core of
the precipitation would come pre-daybreak Wednesday as the upper
wave and sfc low pass across far Southern Lower.

The best snow accumulations with this system will likely occur just
north of the track of the sfc low. Right now, the track of the low
is expected to cross far Southern Lower, putting the heaviest snow
axis near the I-96 corridor. The track of this low and the wave are
expected to be tweaked a little since we are still 4 days away. That
is looking to be the system that has the best chance to bring the
most snow to the area. Areas near the track of the low and south are
likely to see rain mix in with sufficiently warm enough temperatures
present.

It looks like that once the late Tue/early Wed system departs the
area, we will see a relatively quiet period then through Friday with
small to no chance of snow.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 638 AM EST Sat Dec 6 2025

Based on radar trends and the latest observations, it seems that
the threat of freezing drizzle is diminishing. KGRR and KLAN have
had some 4SM BR, which is likely some freezing drizzle/freezing
mist, but nothing significant. The radar had some light echoes
which looked like freezing drizzle also earlier, but it too has
diminished. Based on these trends, we have kept it out of the
forecast at this time.

We will see winds veer from the WSW to NW this morning as a weak
front moves through. Any reduction to visibility will improve, and
ceilings will lift some. MVFR conditions will rule through the day
and into the evening.

We will see light snow break out from West to East overnight. The
MVFR ceilings are likely to persist until the snow starts. Then
the visibilities and ceilings will drop to IFR just before the end
of this forecast period.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 7 PM EST this evening for LMZ844>849.

&&

$$

DISCUSSION...NJJ
AVIATION...NJJ