375
FXUS63 KGRR 061040
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
640 AM EDT Sun Sep 6 2026

.KEY MESSAGES...

- Dry through Labor Day

- Chance of showers/storms Tuesday night/Wednesday

&&

.DISCUSSION...
Issued at 258 AM EDT Sun Sep 6 2026

- Dry through Labor Day

IR loop shows clear skies across the region as high pressure moves
overhead. A light east wind is advecting drier air in from Ontario
and we`ll see humidity levels lower today, along with cooler
temperatures; highs will be in the upper 70s. Low temperatures
tonight will fall into the mid 40s in the northeast cwa and lower
to mid 50s elsewhere. A building high over the central US will
begin to drift east on Labor Day and temperatures will rise a few
degrees, but still remain near normal highs in the upper 70s.

- Chance of showers/storms Tuesday night/Wednesday

The high will continue to be nudged eastward and flattened aloft
as an upper short wave pushes a cold front into the western Great
Lakes. We`re beginning to get into the time of year that cold
fronts from the west have stronger support aloft due to higher
temperature gradients between southern Canada and the northern
half of the US and thus create more lift as they collide with the
warmer, more humid airmass to the south. The models show this
occurring Tuesday night as a cold front moves south into Lower MI.
Precipitation chances rise to 70-80 percent Tuesday night and
Wednesday morning. Another half inch of rain looks possible as the
front moves through.

The latter half of the week looks dry as high pressure builds into
the Great Lakes. Highs in the upper 70s will be common Wednesday
through Friday.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 638 AM EDT Sun Sep 6 2026

Skies are clear across the region. Some VFR cu may develop later
this morning but will dissipate toward sunset. Light ENE winds are
expected through the period.

&&

.MARINE...
Issued at 258 AM EDT Sun Sep 6 2026

Wind and waves will continue to be fairly light through Labor Day
due to high pressure moving overhead. However, once the high moves
east Tuesday, winds will increase and a small craft advisory will
probably be needed.

&&

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

&&

$$

DISCUSSION...04
AVIATION...04
MARINE...04