Grand Rapids, Michigan 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

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FXUS63 KGRR 130748
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
348 AM EDT Wed Aug 13 2025

.KEY MESSAGES...

- A Little Cooler and Drier Next Couple Days

- Hot This Weekend With Showers/Storms Possible

&&

.DISCUSSION...
Issued at 348 AM EDT Wed Aug 13 2025

- A Little Cooler and Drier Next Couple Days

Areas of fog and low stratus will lift and scatter out later this
morning. Dew points will drop today as drier air mixes down,
reaching the 50s in central Mich and mid 60s in southern Mich.
Temperatures will be near mid-August normals through Thu night.
Only spoiler may be some moderate AQI smoke infiltrating into
portions of Lower Michigan per upstream air quality monitors and
the (experimental) HRRR-Smoke.

- Hot This Weekend With Showers/Storms Possible

Large scale ridging will build over the central CONUS late in the
week, and 850 mb temperatures nearing 20 C return on Saturday. Dew
points are also expected to climb and the heat index should be
well into the 90s on Sat. Michigan will tend to be just downstream
of the 500 mb ridge with some ridge-riding shortwaves supporting a
round or two of scattered thunderstorms. Storm chances are
relatively higher up north on Saturday and may affect our part of
Michigan later Saturday into early Sunday.

Ensembles are split whether the cold front sags south enough to
provide a cooler and drier Mon-Tue, or if there will be another
surge of humid and unstable air with additional storm and heavy
rain chances during that time.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 153 AM EDT Wed Aug 13 2025

MVFR to IFR ceilings and/or visibility is likely to spread over
most of the area as humidity near the ground is high, winds are
light, and skies are partially clearing. Improvement is expected
13 to 16 Z as cloud bases lift and scatter MVFR into VFR.

&&

.MARINE...
Issued at 348 AM EDT Wed Aug 13 2025

Light north winds are expected to strengthen out of the northwest
to around 15-20 knots this afternoon, per high resolution models
which better capture the effects of high pressure nosing in paired
with the developing lake breeze. Generally 2 to 3 ft waves today,
with 3 to 4 ft waves and moderate swim risk later this afternoon
between Whitehall and South Haven.

The weekend into early next week will feature chances for
thunderstorms to occasionally cross Lake Michigan.

&&

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

&&

$$

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