884
FXUS63 KGRR 201037
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
637 AM EDT Sat Jun 20 2026
.KEY MESSAGES...
- Cooler than normal with occasional rain
&&
.DISCUSSION...
Issued at 204 AM EDT Sat Jun 20 2026
- Cooler than normal with occasional rain
The Great Lakes region will continue to be in a fast quasi-zonal
flow regime on the southern edge of persistent upper troughing
across eastern Canada into next week. This will keep temperatures
below normal with fast-moving shortwave troughs bringing the
chance for rain late Sunday night and again on Wednesday.
The best chance for rain will be across southern Lower Michigan on
Sunday night as low pressure tracks across northern Indiana and
Ohio. An area of mid-level frontogenetic forcing should bring
steady rain across the I-94 corridor with QPF of around one inch
by the time the rain ends on Monday. There will be a sharp
gradient to the north with around a quarter inch along I-96 and
less than a tenth of an inch north of there.
A weaker low follows for Wednesday in northwest flow and precip
amounts will probably be less than a quarter inch.
&&
.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 637 AM EDT Sat Jun 20 2026
VFR conditions will continue through today and tonight. West winds
may gust over 20 knots at times this afternoon before decreasing
blo 10 knots this evening.
&&
.MARINE...
Issued at 204 AM EDT Sat Jun 20 2026
Fairly tranquil conditions into Sunday then winds and waves will
increase Sunday night as low pressure passes just south of Lake
Michigan. A SCA may be needed for Monday.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Ostuno
AVIATION...Ostuno
MARINE...Ostuno
NWS GRR Office Area Forecast Discussion
