506
FXUS63 KGRR 110826
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
326 AM EST Thu Dec 11 2025

.KEY MESSAGES...

- Lake Effect Snow into the Weekend

- Cold Temperatures this Weekend into Monday

- Potential Warm Up Next Week

&&

.DISCUSSION...
Issued at 326 AM EST Thu Dec 11 2025

- Lake Effect Snow into the Weekend

Northwest winds off of Lake Michigan will bring lake effect snow
and flurries to the area today. The better bands are to the north
with the combined moisture and fetch of Lake Superior and Lake
Michigan. Areas along and north of US-10 have the potential to
see the southern ends of these bands today, however accumulations
will be light with amounts of an inch or less.

Tonight a system will pass largely to the south, but far southwest
Michigan could get clipped with snow late tonight into Friday
morning. Little to no accumulation is expected.

A better shortwave moves through Friday evening into Saturday
morning bringing with better low level moisture and a colder air
mass over Lake Michigan. The dendritic growth zone will be closer
to the surface limiting synoptic lift in this area along with an
inversion preventing the moisture profile from becoming deep.
Lapse rates will be decent along the lakeshore with computed
instability off of the lake temperatures around 300 J/kg. The 25th
to 75th percentiles show most of the lakeshore seeing 1 to 3
inches, with a 30 percent chance of seeing 4 inches or more. The
better potential for these higher amounts will be in Ottawa
Allegan, Kalamazoo, and Van Buren Counties in the south and
Ludington County to the north. We`ll have to watch for a slight
change in the wind direction as that will impact where those
higher probabilities set up.

As we continue Saturday afternoon into Sunday the air mass
becomes colder with steeper laps rates, but the dendritic growth
zone will be at the surface. Shallower moisture and with lift
better above the dendritic growth zone will limit amounts.

- Cold Temperatures this Weekend into Monday

The bulk of our cold arrives Saturday with 925 mb temperatures
around -15C resulting in highs in the teens and lows in the single
digits with some spots potentially dropping below zero. Wind
chills will be in the single digits above and below zero
throughout the day Saturday. Temperatures slightly improve Sunday
with highs in the low 20s with wind chills in the single digits to
low teens. Similar conditions are expected Monday.

- Potential Warm Up Next Week

Temperatures look to warm after Monday with high temperatures
rising above freezing for Wednesday and Thursday. There is a
concern with these warmer temperatures as there are a few
shortwaves that move through the flow. Depending on timing will
impact the precipitation type. If we see any rain, there will be
a concern for freezing rain due to the cold ground temperatures.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1132 PM EST Wed Dec 10 2025

Radar continues to show light returns indicative of very light
snow showers/flurries across the terminals. Conditions will be
favorable for flurries much of the night before drier air moves in
toward sunrise.

Short range models also show several hours of MVFR cigs from mid
morning through early to mid afternoon and then lifting back to
VFR. There is a wave of low pressure that will move across Indiana
Thursday night but the precipitation will remain south of the
terminals.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 4 PM EST this afternoon for
     LMZ844>849.

&&

$$

DISCUSSION...RAH
AVIATION...04