852
FXUS63 KGRR 071748
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
148 PM EDT Tue Oct 7 2025

.KEY MESSAGES...

- Showers linger today along slow-moving front

- Frost/Freeze for Tonight, Wednesday night

&&

.DISCUSSION...
Issued at 221 AM EDT Tue Oct 7 2025

- Showers linger today along slow-moving front

The upper ridging of the past week is being replaced by a trough
moving through the next couple days. For today, a band of showers
and isolated thunderstorms will be slowly sinking south and east
across the forecast area through this afternoon.

An axis of marginal instability along with deep layer shear of 25
to 30 knots will be along southern Lower Michigan early this
morning and transient bowing line segments could bring an
isolated wind threat before the surface cold front clears that
area. Showers and isolated post-frontal elevated thunderstorms
could persist until afternoon across the far southeast.

Northerly flow of drier air will result in clearing skies this
evening.

- Frost/Freeze for Tonight, Wednesday night

Surface high moves over the Great Lakes region bringing much
cooler temperatures. Lows tonight will fall into the 30s with
areas of frost across the northern interior. There could be
enough wind persisting to prevent widespread freezing
temperatures until Wednesday night when the surface ridge axis is
across Lower Michigan, allowing winds to decouple, providing more
optimal radiational cooling conditions.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 148 PM EDT Tue Oct 7 2025

IFR to MVFR conditions will gradually lift as the rain shifts east
this afternoon. Light northerly winds and clearing skies are
expected overnight into Wednesday. MKG and other areas along the
lakeshore may briefly gust toward 20 knots tonight around 6Z,
otherwise winds shift to the northeast at around 5 to 10 knots.

&&

.MARINE...
Issued at 148 PM EDT Tue Oct 7 2025

No changes are expected to the Small Craft Advisory for areas
south of Holland. Northerly gusts to 25 knots and wave heights 3
to 5 feet are expected. Further north winds and waves could
briefly approach Small Craft Advisory levels late tonight, but
light northeast winds and falling waves heights are expected by
Wednesday morning. Southerly winds and waves may approach Small
Craft Advisory levels again on Friday. Southeast winds Sunday may
be close to Small Craft Advisory levels as well, but the wind
orientation should help keep waves below criteria with the
highest waves beyond 5 NM.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 5 AM EDT Wednesday for LMZ844-845.

&&

$$

DISCUSSION...Ostuno
AVIATION...RAH
MARINE...RAH