144
FXUS63 KGRR 060640
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
240 AM EDT Sun Jul 6 2025

.KEY MESSAGES...

- Fairly quiet weather pattern continues with weak shortwave
 troughs moving through quasi-zonal flow, bringing occasional
 chances for rain through mid-week.

&&

.DISCUSSION...
Issued at 330 PM EDT Sat Jul 5 2025

- Fairly quiet weather pattern continues with weak shortwave
 troughs moving through quasi-zonal flow, bringing occasional
 chances for rain through mid-week.

A few scattered showers have formed this afternoon along
horizontal roll circulations over the east central zones and these
should remain isolated and then diminish this evening in a regime
of general subsidence in upper ridging. Heights fall overnight as
the ridging breaks down and showers and storms currently across
Wisconsin advance east.

These showers will arrive across the northwest zones after
midnight then slowly advance southeast as the baroclinic zone
becomes aligned with the upper flow. The showers should persist
from Sunday then push off to the southeast by Monday morning.

Mostly dry weather then prevails into Tuesday under weak high
pressure before the next shortwave trough approaches and brings
another round of scattered convection for Tuesday night and
Wednesday. The potential for organized convection is limited by
relatively weak deep layer shear of around 25 knots or less.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 240 AM EDT Sun Jul 6 2025

MVFR to IFR ceilings from the north will spread into MKG this
morning. MVFR ceilings will gradually spread southeastward,
reaching GRR later in the morning (approximately 15Z) and JXN by
no later than this evening (approximately 02Z), per a consensus of
short-term models. But flight category is liable to drop to
temporary IFR sooner than ceilings would suggest due to moderate-
heavy rain showers and scattered thunderstorms. These should
affect MKG and GRR vicinity this morning then GRR vicinity and
many areas south and east of GRR this afternoon.

&&

.MARINE...
Issued at 330 PM EDT Sat Jul 5 2025

Winds and waves today will continue to build, becoming hazardous to
small craft and to beach goers late this afternoon and into the
evening. The main beaches of concern will be north of Grand Haven.
Winds and waves will subside overnight but will increase again
tomorrow. Winds and waves will be out of the north behind the
cold front and should be hazardous to beach goers along all
beaches tomorrow afternoon and evening, north facing beaches and
the north side of piers will be particularly dangerous.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through this evening for MIZ037-043-050-
     056.
MARINE...Small Craft Advisory until 8 PM EDT this evening for LMZ846>849.

&&

$$

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