Gowen, Michigan Weather Forecast Discussion

891
FXUS63 KGRR 222325
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
725 PM EDT Mon Sep 22 2025
.KEY MESSAGES...
- Scattered Showers/Storms Much of This Week
- Dry Weather Likely for the Weekend
&&
.DISCUSSION...
Issued at 300 PM EDT Mon Sep 22 2025
- Scattered Showers/Storms Much of This Week
An upper trough located across WI into the U.P. this afternoon
will slowly move east into tomorrow before slowing down and
closing off as an upper low directly overhead the region
Wednesday into Thursday. What this will lead to is pretty
extensive cloud cover for a few days but also scattered, mainly
diurnally driven showers and thunderstorms across the Lower
Peninsula.
For tonight, a weak LLJ initially oriented SW to NE will start
angling more eastward and then southeastward across the region,
perhaps touching off scattered showers/storms overnight near and
east of where today`s convective activity developed (which was
over Lake Michigan into west central Lower MI). This scenario is
favored by most CAMs. Currently the most likely region to receive
some rain tonight is near and north of I-96, though given timing
and location differences by the CAMs most probabilities are
30-50%.
Tuesday doesn`t look much different than today in terms of morning
low cloud cover and scattered diurnal showers and a few storms
developing. Widespread rain is not expected. For Wednesday, given
the upper low placement overhead we`ll see 850 mb winds converge
across the eastern half of the region as PWAT values likely reach
their peak for this event, getting close to 1.50" which is about
175% of normal for late September. What this equates to is
whatever showers and thunderstorms do develop, they could be heavy
rain producers with slow storm motions. Certainly wouldn`t be
surprised to see areas especially near and east of US 131 pick up
an additional inch or more of rain. The upper low takes its sweet
time moving out on Thursday so we can`t drop rain chances until
that exits the region.
- Dry Weather Likely for the Weekend
Good ensemble agreement exists on a dry weekend. Upper heights
build into Friday, and upper troughing is expected to stay
primarily north of the state on Saturday as heights resume
building into Sunday. Looks like a fair amount of sunshine as
well, along with light winds. Highs should reach the mid to upper
70s.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 725 PM EDT Mon Sep 22 2025
Ongoing VFR conditions will notably deteriorate overnight after
05z-09z. Dewpoints in the 60s this afternoon will support
elevated crossover temperatures, which in combination with light
winds, will lead to the development of fog and low stratus
overnight. JXN looks to see the worst conditions with LIFR chances
near 50 percent. IFR is likely LAN, GRR, AZO, and BTL with lower
(around 20-30 percent) chances of LIFR. Some uncertainty exists
however with fog and low cloud development. Assuming IFR and lower
stratus develop as expected visibilities should hold mainly in
the IFR range with periods of LIFR possible at JXN. However, if
stratus coverage is less than expected LIFR and lower visibilities
are possible. Have tailored the TAFs towards the first scenario
but satellite trends will need to be monitored.
MKG will see conditions a bit better than the other sites with
MVFR favored though around a 30-40 percent chance of IFR
conditions exists. Scattered showers are likely to develop in the
early part of the overnight, and these showers may clip GRR as
well. Isolated thunderstorms are possible but will not include
thunder in the TAFs at time.
&&
.MARINE...
Issued at 300 PM EDT Mon Sep 22 2025
Fairly tranquil conditions expected on the lake this week with
light winds expected and as a result, little in the way of wave
activity. The highest waves will likely occur on Thursday south of
the Holland area with some 2 to 3 footers possible.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Hoving
AVIATION...Thomas
MARINE...Hoving

NWS GRR Office Area Forecast Discussion