802
FXUS63 KGRR 150739
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
239 AM EST Sat Nov 15 2025

.KEY MESSAGES...

- Windy and 20 Percent Chance for Showers Today

- Potential for Rain/Snow Mix Tuesday

- Additional Rain Chances Toward the End of Next Week

&&

.DISCUSSION...
Issued at 239 AM EST Sat Nov 15 2025

- Windy and 20 Percent Chance for Showers Today

High clouds are streaming overhead within the ridge axis. Lower
clouds are expected to move in later this morning and afternoon as
warm air advection 850mb low level jet convergence, and positive
vorticity advection move in with the shortwave trough. The one
limiting factor is moisture. Even with precipitable water values
around 0.80 inches, soundings have a hard time becoming saturated
as the shortwave moves through. Therefore PoPs are limited to 20
percent this morning and afternoon for light rain.

However gusty winds are more likely during the afternoon and into
tonight with the 30 to 40 knot winds aloft. We should start to mix
some of these gusts down to the surface during the late morning
and afternoon initially from the southwest then turning to the
northwest during the afternoon and evening. Gusts of 30 to 40 mph
are expected so make sure to secure any loose objects or
decorations.

With the northwest flow areas around US-10 and north could see
some light lake effect showers. Lake Superior will be feeding
moisture into the northern Lower Peninsula. Best chances (20 to
30 percent) for light snow will be in Clare County with the
expected orientation of the bands.

- Potential for Rain/Snow Mix Tuesday

A weak mid level low will move from Colorado into the southern
Great Lakes area Tuesday. A tight gradient of precipitation is
expected along the low level warm air advection and frontogenesis.
This is also seen in the low to mid level moisture fields. There
are signals in the ensembles that this axis of precipitation could
remain just south of the area, however there are still solutions
that have the wintry mix across southwest Michigan. Therefore
there are no adjustments to the NBM PoPs. If we see this axis of
precipitation it will likely be snow initially then transition to
rain as we lose cloud ice. There is a slight chance (20 percent)
for a brief period of freezing rain Tuesday night before the rain
ends.

- Additional Rain Chances Toward the End of Next Week

Looking at the cluster analysis a strong low pressure system is
expected to move through the Great Lakes Region. There is a bit of
uncertainty with the timing and track as seen in the varying
cluster groups. There could be some instability to work with along with
a strong low level jet. Overall the signal is there for wet
weather late in the week especially with wind flow originating
from the Gulf. We`ll just need to monitor the trends for the exact
timing and where has the best chance for some rain.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1213 AM EST Sat Nov 15 2025

South to southwest winds will increase as we head from tonight
into Saturday in advance of an approaching cold front. The front
at 05z stretches across portions of Minnesota and South Dakota
surging southeast. The front will move into Lower Michigan after
12z on this morning. Clouds will thicken Saturday morning as the
front moves in with MVFR ceilings becoming dominate after 12z.
There is the potential for IFR cigs with MVFR vsbys mainly from
12Z to 18Z with another period possible 19Z to 21Z. There is the
chance for a few showers, but the trend looks to be that most TAF
sites will remain dry.

Winds will be the main item of note as southwest winds increase to
12-25 knots with gusts towards 30 knots. Winds will be shifting to
the west and northwest in the afternoon with similar speeds. A few
gusts in the afternoon may exceed 30 knots.
 Have added LLWS as a strong LLJ is ahead of the front This will
bring winds out of a more westerly direction around 1KFT to 2KFT.
That jet will affect the western TAF sites primarily . After
Frontal passage the jet will move eastward.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 1 PM EST Monday for LMZ844>849.

&&

$$

DISCUSSION...RAH
AVIATION...Ceru