701
FXUS63 KGRR 301737
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
137 PM EDT Thu Jul 30 2026

.KEY MESSAGES...

- Rain Chances Return Friday Night into Saturday

- Additional Rain Chances Tuesday Night into Wednesday

&&

.DISCUSSION...
Issued at 137 PM EDT Thu Jul 30 2026

- Rain Chances Return Friday Night into Saturday

Dry conditions continue through most of Friday, but an advancing
mid level trough and surface low will move in Friday night into
Saturday. There is a 20 percent chance of an isolated shower
before 8pm, otherwise chances increase to around 70 to 80 percent
by Saturday morning. There is the potential (20 percent) for
thunder with the rain into Saturday. Overall probabilities are
higher that amounts will remain under an inch, however there is a
30 to 40 percent chance of amounts over an inch across the area,
with an isolated 20 percent chance of greater than 2 inches
through Saturday. WPC currently has the area in a marginal risk
for excessive rainfall Friday night into early Saturday morning.
If we see more low to mid level support with the low pressure
system tracking to the south, higher rainfall amounts will be
possible and may cause some minor flooding. Showers slowly clear
Saturday night into Sunday morning with dry conditions expected
through Tuesday.

- Additional Rain Chances Tuesday Night into Wednesday

Pressure heights fall again with another shortwave trough moving
through midweek next week. Overall the wave is rather open and
shallow, therefore not expecting any significant rainfall or
thunderstorm potential. Probabilities for rain are 20 to 30
percent with the best chances for any thunder Wednesday afternoon.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 137 PM EDT Thu Jul 30 2026

VFR is expected through Friday morning with winds between SW and
NW 5 to 10 knots. Scattered to broken cumulus bases around 6,000
feet are developing with daytime heating in Mid Michigan.

&&

.MARINE...
Issued at 137 PM EDT Thu Jul 30 2026

High pressure continues bringing pleasant conditions on the water
and on the beach. Waves today are a foot or less with westerly
winds 5 to 10 knots. Winds shift to the southwest tonight and
continue through Friday before a low pressure system tracks to our
south bringing northeast winds. Saturday winds and waves may
approach Small Craft Advisory conditions, but wave heights will be
lower right along the lakeshore due to the offshore flow. Breezy
northeast winds will continue into Sunday before light easterly
winds return for Monday.

Rain is expected to move in Friday night and continue through
most of Saturday. A few rumbles of thunder are possible, but the
overall chance is low. Lower visibilities are likely with moderate
to heavy rain.

&&

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

&&

$$

DISCUSSION...RAH
AVIATION...CAS
MARINE...RAH