739
FXUS63 KGRR 071132
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
732 AM 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 /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 732 AM EDT Tue Oct 7 2025

Areas of IFR and patchy LIFR in low stratus will be found across
southern Lower Michigan this morning before drier air moves in
later this afternoon and VFR conditions return. Winds will be
north around 10 knots.

&&

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

North winds around 10 to 20 knots today with waves potentially
building to 3 to 5 feet for a few hours this evening. Will hold
off on a small craft advisory at this time given the marginal and
transient threat. High pressure building in will bring more
tranquil conditions for Wednesday and Thursday.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

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