994
FXUS63 KGRR 102344
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
744 PM EDT Fri Oct 10 2025

.KEY MESSAGES...

- Chance of rain through tonight

- Mainly dry Saturday through Tuesday

- Above average uncertainty for Wednesday through Friday

&&

.DISCUSSION...
Issued at 335 PM EDT Fri Oct 10 2025

- Chance of rain through tonight

A few sprinkles or very light showers are in the process of passing
through the forecast area this afternoon. As of 3 pm, they extended
from Saginaw Bay, through Grand Rapids, and to Southern Lake
Michigan. These sprinkles are mainly the result of good forcing
aloft ahead of the incoming upper low, without much in the way of
moisture below 6k ft agl.

We will see low level moisture increase through this evening ahead
of the cold front, which stretches from near Manitowoc, WI to the
Tip of the Mitt as of 3 pm. However, as we increase the low level
moisture, the mid and upper level moisture is moving out quickly.
The bottom line to this is that there will be scattered light
showers around this evening until the front moves through late this
evening and overnight.

- Mainly dry Saturday through Tuesday

We are looking at dry conditions settling in over the area on
Saturday behind the sfc cold front. There has been a lot of
uncertainty regarding this low for the last week. Now that we are
looking at the whites of its eyes, it looks like it will end up well
east of the forecast area by tomorrow. This means that the coldest
of the air aloft will be also, and the threat of any showers has
diminished significantly. Can`t rule out maybe some lake effect
clouds or a few showers with the degree of colder air coming in at
the sfc with sfc-850 mb delta t`s in the mid teens C. The flow will
be from the NE, so anything from Lakes Michigan and Huron should
stay out of the area.

Upper ridging will build in then by Sunday, clearing out the area
nicely. The building upper heights, and low level flow becoming more
from the south will help max temps recover nicely to the 70s for
Sunday and Monday.

A weak cold front will be sinking SE into the area as the upper
ridge axis shifts east, and the upper jet approaches the area. This
will allow some weak short wave activity to clip the area across the
north. The front will approach, and will weaken with the lack of
sufficient upper support. In addition, any impacts in the way of
rain will be quite low as the low level feed of air comes from the
SE, downsloping off of the Appalachians. The small chance of rain
will linger into Tuesday when the front drops through.

- Above average uncertainty for Wednesday through Friday

Forecast certainty drops off significantly starting Wednesday and
beyond. This uncertainty all has to do with how long the slightly
lower heights and upper jet persist, before upper ridging builds
once again. NBM/the forecast has some small chances of rain at times
Wednesday-Friday. The bottom line is we should not see any
significant systems in that time frame, and temperatures will remain
seasonable to a little above average.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 744 PM EDT Fri Oct 10 2025

A cold front moving through the region this evening will bring a
period of mainly VFR ceilings to the TAF sites along with very
light rain showers that will not affect visibility. In the 06z to
14z time frame most of the TAF sites will become mostly clear.
Clouds will once again advance in from the north in the wake of
the front as the low passes off to the east. After 14z, 2500-4000
foot ceilings will spread in. The I-96 TAF sites stand the best
chance of seeing the lower/MVFR ceilings. These lower ceilings
will last into the early afternoon before lifting to VFR and/or
scattering out around 18z. Winds will veer to the north tonight
behind the front and northeast on Saturday during the day.

&&

.MARINE...
Issued at 335 PM EDT Fri Oct 10 2025

Waves of 4 to 6 feet are being reported at the buoys at 300pm. The
mid lake buoy west of Ludington reached 7.5 feet earlier today. Big
Sable Point is currently gusting to 30 knots. Webcams show whitecaps
to the horizon. The Small Craft Advisory (SCA) is working out well.

High end SCA conditions will continue this afternoon and early
evening. Winds will tone down a bit after 00z and especially after
02z. Wind direction will shift to the north this evening behind the
front, but winds decrease as the surface low is filling and we
remain in a slightly baggy gradient. The end time of our Small Craft
Advisory (11am Sat) still looks good as the winds will be veer
northeast/offshore. Winds into Saturday night and Sunday will remain
east/offshore and lighter, so we will remain at sub advisory levels
through the rest of the weekend.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 11 AM EDT Saturday for LMZ844>849.

&&

$$

DISCUSSION...NJJ
AVIATION...Duke
MARINE...Duke