textproduct: Grand Rapids

KEY MESSAGES

- Northwest flow regime with occasional chances for rain but low confidence in convective details

UPDATE

Issued at 953 AM EDT Sun Jul 26 2026

Latest forecast trends suggest a low risk of showers and storms this afternoon. However with the lack of a robust forcing source, storm coverage looks to be isolated. With strong deep layer shear and ample DCAPE could see strong to damaging winds, and maybe large hail, if we can get robust thunderstorm development. However, given limited forcing uncertainty remains as to if/where any storms can develop.

Water Vapor satellite imagery also shows a mid-level wave across the Northern Plains. Expectation is for this wave to initiate storms across northern Minnesota/Wisconson this afternoon/evening, which then track southeast along the advancing instability gradient. Model solutions do vary with the eastward extent of this instability plume, which could keep storms west of our area, or see them reach areas mainly west of US-131 late this evening into tonight. Expectation would be upscale growth into clusters with damaging winds as the main concern and large hail as a secondary concern. Mesoscale trends will continue to be monitored into the evening to evaluate whether storms will reach West Michigan or miss us to the west.

DISCUSSION

Issued at 211 AM EDT Sun Jul 26 2026

- Northwest flow regime with occasional chances for rain but low confidence in convective details

The Great Lakes region remains in between an upper high across the western CONUS and longwave troughing across the eastern CONUS with occasional shortwave troughs passing through and bringing the chance for some much-needed rain.

A weakening shortwave trough moving through early this morning has yet to initiate any showers, which is not surprising given limited moisture and lift. Isolated showers are possible through the afternoon.

Still low confidence in the details of how things play out tonight through MOnday night in terms of organized convection, but instability and shear are sufficient for a slow-moving front and weak midlevel vorticity max to focus convection across Minnesota and into Wisconsin this afternoon which eventually moves southeast across Lake Michigan and perhaps western Lower Michigan.

The hi-res convective allowing models take the bulk of the storms west of our forecast area, but there is a chance an MCS could impinge on the western or southwest zones late tonight or early Monday morning. Additional convection is possible across the rest of the forecast area during Monday and Monday night as the front pushes south.

The front moves through by Tuesday with fair weather for mid to late week before the longwave upper trough amplifies with a cold front bringing another chance of rain by next weekend.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 704 AM EDT Sun Jul 26 2026

Patchy IFR/MVFR conditions with low stratus this morning should go over to VFR by 18Z. There could be some rain moving in tonight across western Lower Michigan, with MKG having the best chance late tonight. Winds will be from the southwest AOB 10 knots.

MARINE

Issued at 211 AM EDT Sun Jul 26 2026

Today should see a continuation of southwest winds around 10 to 15 knots then thunderstorms could bring strong wind gusts over Lake Michigan tonight. A cold front moves through Monday night and north winds increase to near 30 knots with waves building over 4 feet on Tuesday and continuing into Wednesday.

GRR WATCHES/WARNINGS/ADVISORIES

MI...None. MARINE...None.