173
FXUS63 KGRR 021740
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
140 PM EDT Wed Jul 2 2025

.KEY MESSAGES...

- Scattered Showers/Storms Possible Today through Friday

- A Better Chance for Showers/Storms Saturday night and Sunday

- A Warmup into Saturday then a Slight Cooling Next Week

&&

.DISCUSSION...
Issued at 348 AM EDT Wed Jul 2 2025

- Scattered Showers/Storms Possible Today through Friday

Several chances for showers and storms exist today through Friday
with the first occurring this afternoon and evening. A weak
surface boundary will sag south into the area this afternoon. That
front combined with some convergence in the interior portion of
the state will drive some scattered shower and thunderstorm
activity. The eastern CWA towards Highway 127 has the best chance
this afternoon and then Central and Western Lower get into the act
in the late afternoon and evening. A shortwave will be working
through the flow aloft so there will be some support for
convection today. We are in the SPC marginal today, but any chance
at severe looks pretty low. An outside chance at some localized
stronger winds would be the main threat (50-60mph). Some of the
activity will last until after sunset before fading.

The boundary remains in the area on Thursday albeit very weak. It
will be a location of some convergence however and with an
unstable airmass not out of the realm that we may see some
scattered showers and storms. The HREF is focusing on areas from
Grand Rapids south and east through Battle Creek, Lansing and
Jackson. We are in a day two Marginal as well, but again severe
threat looks limited.

We have gone dry for the Fourth, but would not be surprised to see
some scattered showers and storms developing along a warm front.
Agree with the previous discussion that the rising heights may put
a lid on anything that tries to develop and actually that is what
we are leaning on at this point.

- A Better Chance for Showers/Storms Saturday night and Sunday

A cold front pushes into the area Saturday night and progresses
through on Sunday. We have 40-60 pct chances for rain in the
forecast with this frontal passage. This will not be a washout by
any means, but there will be some rain around.

- A Warmup into Saturday then a Slight Cooling Next Week

A steady warm up will continue into Friday and Saturday followed
by a cooling back to normal into early next week. 850mb
temperatures peak Saturday into Saturday night around +20C. This
will result in highs on Saturday into the 90s. We will be well
into the 80s to around 90 today through Friday, so summer like
weather is certainly in the forecast for the Fourth weekend. Early
next week we cool back into the lower teens C at 850mb which has
our forecast highs around normals...near 80 to the lower 80s.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 135 PM EDT Wed Jul 2 2025

Diurnal cu will dissipate around sunset leaving mostly clear
skies. However, a weak upper trough moving across the region may
produce a shower near LAN/JXN after 19z; a thunderstorm is also
possible but just mentioned a chance of showers at those
terminals. Radar shows a few showers developing along/east of
US-127 currently and those are moving ESE.

It`s also possible that MKG could see a shower/storm around 06z
from convection moving southeast from northeast Wisconsin and
northern Lower, but models are less than clear on that signal.
Otherwise, VFR expected through the period.

&&

.MARINE...
Issued at 135 PM EDT Wed Jul 2 2025

Waves will remain aob 2 feet through Friday before southwest winds
increase Saturday. Waves will increase to 2-4/3-5 ft north of
Whitehall Saturday afternoon and a small craft advisory may be
needed then.

&&

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

&&

$$

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