880
FXUS63 KGRR 111915
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
315 PM EDT Tue Aug 11 2026

.KEY MESSAGES...

- Showers and storms moving to the South; Patchy fog overnight

- Chances for storms tomorrow

- Next chance for Showers/storms over the weekend

&&

.DISCUSSION...
Issued at 303 PM EDT Tue Aug 11 2026

- Showers and storms moving to the South; Patchy fog overnight

 The quasistationary boundary continues to sag southward and will
push any showers/storms in that direction. There has been some
light rain along the I 94 corridor, with the anvil from the
thunderstorms through southern Michigan bringing some rumbles of
thunder and vicinity lighting to that region. However, the storms
themselves continue their southward trek toward the southeast.
 Light winds, a moist surface layer and recent rainfall is a
recipe for patchy fog overnight into Wednesday morning. Expect
this fog to be dense at times and will linger through the morning
commute.

- Chances for storms tomorrow

Though there is a signal for decent CAPE values from the SFC
moisture and daytime temperatures into the 80s, the atmosphere is
fairly stable, especially since the boundary remains to the south.
Latest HREF does show the potential for a weak mid level trough
and some shear through northern lower Michigan in the afternoon.
That could take advantage of the 1K J/kg of CAPE Wednesday
afternoon. For those reasons, SPC has a ribbon of marginal risk of
severe storms through the central and northern half of Lower MI
tomorrow afternoon and evening.


- Next chance for Showers/storms over the weekend

The large upper level low over northern Canada continues to send
waves through Michigan through th week. However, we remain fairly
stable through the latter half of the week with temperatures at,
to below normal into the weekend.
 A large upper level low will move into the the Great Lakes
region through the area mid to late weekend with chance for rain
into Sunday.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 201 PM EDT Tue Aug 11 2026

While stratiform rain overspreads the region the anvil from the
storms over southern MI is spreading over the southern TAF sites.
This has allowed for VCTS at AZO and can`t rule it out for BTL.
Not expecting TSRA as the storms should move southward as the
boundary pushes in that direction. That said, can`t rule out VCTS
for the next few hours at AZO and BTL. Light showers will
overspread the region and there remains a chance for TSRA at the
southern TAF sites through 00Z.
 Another round of IFR cigs and vsbys in fog/mist and low stratocu
will be possible overnight into Wednesday morning. Expect showers
reducing cigs and vsbys from around 05Z until 13Z. Conditions
should improve from 13Z to 15Z Wednesday.

&&

.MARINE...
Issued at 312 PM EDT Tue Aug 11 2026

Showers and storms will move to the south this afternoon and
evening. A typical mid summer weather pattern will continue the
next few days. Light winds will continue. Expect sunshine and
some of our warmest water temperatures. Winds and waves will
remain fairly light through tomorrow.


&&

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

&&

$$

DISCUSSION...Ceru
AVIATION...Ceru
MARINE...Ceru