textproduct: Grand Rapids

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.