704
FXUS63 KGRR 281715
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
115 PM EDT Sat Jun 28 2025

.KEY MESSAGES...

- Sunday Heat

- Main Precipitation This Week Occurs Monday into Monday Night

- Otherwise...Mainly Dry and Seasonably Warm

&&

.DISCUSSION...
Issued at 342 AM EDT Sat Jun 28 2025

- Sunday Heat

Sunday looks to be a hot day with 850mb temperatures pushing to
+21C per the ECWMF. High temperatures will likely range from 88 to
93. Dew point temperatures will be around 70 which will push heat
index values towards 100 in spots in the afternoon. For now
holding off on a Heat Advisory as it looks like conditions for
most of the area will be just shy, but not out of the realm of
possibilities of needing a headline for Sunday afternoon.

- Main Precipitation This Week Occurs Monday into Monday Night

The main precipitation chances in the 7 day forecast comes Monday
into Monday night as a cold front pushes through the state. The
upper pattern shows a shortwave trough pushing our direction from
the Northern Plains which slides through our area during this
time. Showers and thunderstorms are likely on Monday and we have
chances for precipitation increasing to 60-90 pct in the afternoon
from GRR to the south and east. Not out of the realm of
possibilities to see a few strong storms Monday afternoon and
evening as it looks like the front moves through at peak heating.
There is some signal for a decent low level jet in the models on
the order of 30 knots with a mid level jet of 40 knots. There
should be solid instability around combined with deep layer shear
approaching 40 knots. The focus for any severe potential in the 7
day forecast is certainly Monday into Monday night.

- Otherwise...Mainly Dry and Seasonably Warm

The remainder of the forecast...this weekend and then Tuesday into
the end of the work week looks pretty uneventful. Temperatures
look seasonable to slightly above normal but nothing out of the
ordinary. Highs should mainly be in the 80s. As for precipitation
chances we look dry this weekend with another small chance at
showers and storms mid week. There is a weak stationary boundary
in the area Wednesday night into Thursday and we could see some
spotty precipitation during this time frame. At this point our
blend of models has a 20 pct chance in the forecast.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 115 PM EDT Sat Jun 28 2025

SCT to BKN cumulus around 3-3.5kft impacting most terminals will
diminish into the afternoon. Skies clear out tonight before mid-
level clouds increase Sunday. West to Southwest winds today become
light overnight and Southerly Sunday. High confidence in VFR
conditions through the TAF window.

&&

.MARINE...
Issued at 342 AM EDT Sat Jun 28 2025

The main story is that we are not expecting any significant beach
or boating weather issues this weekend. Surface ridging will be in
place today and tonight which will keep winds on the light side
(less than 10 knots) which will keep waves small. On Sunday,
southerly return flow begins, but it is not expected to reach
advisory type levels.

Winds strengthen a bit Sunday night into Monday ahead of a cold
front, but at this point we are not expecting conditions to reach
Small Craft Advisory or Beach Hazards Statement criteria.

&&

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

&&

$$

DISCUSSION...Duke
AVIATION...Thomas
MARINE...Duke