textproduct: Grand Rapids

KEY MESSAGES

- Rain focused on this morning; A few showers/storms Sunday

- Warmer with non-zero rain chances Monday through Wednesday

- Seasonable and dry for the end of next week

DISCUSSION

Issued at 246 AM EDT Sat May 23 2026

- Rain focused on this morning; A few showers/storms Sunday

The rain has steadily advanced north to around the I-96 corridor as of 2 am this morning. This is only the beginning with rain extending down to near the Ohio River Valley with the sfc low around there. The low will track steadily into Southern Ontario this afternoon. As it does, the backside of the rain will advance in from the west, and move east of the area by early evening. The rain will not move much further north with the dry flow from the NE eating away at the leading edge. As the rain ends this afternoon, plenty of low level moisture will hold in, possibly keeping some mist/drizzle in a bit longer. Then fog is likely tonight with the very moist lower levels and winds dropping off.

Early Sunday morning around sunrise, we will see a line of a few showers approach the area from the west. These are associated with the long wave low that shows up well on Water Vapor imagery over North Dakota this morning. This low will be making a run east, and will help the rain chances. There could be a few rumbles of thunder later morning and afternoon as we see some diurnal heating bump the instability up in addition to the cooling mid levels.

- Warmer with non-zero rain chances Monday through Wednesday

We see the upper air pattern evolve to more of a zonal flow for Monday and Tuesday behind the departing upper low. Deep moisture gets swept out, so most areas will be dry. A weak short wave is seen coming through Monday afternoon and evening. It is expected to not do much, other than maybe enhance the chance for a shower/storm along the Lake Huron shoreline where the light westerly wind converges with the easterly lake breeze. This should all stay east of our forecast area. Tuesday looks dry everywhere as the upper ridge sharpens up a bit and pushes closer to the area.

Once again, Wednesday should be mostly dry for most areas. However we have a couple of weak features that will bring very small rain chances.

The first feature is a weak short wave trying to lift to the NE from the Plains. This wave tries to also bring some better moisture around, of which most of it should stay just south. We also have a back door cold front poised to move through with the way the upper ridge is building over the area. These two features should not meet over Lower Michigan, so that should limit rain chances to around 20- 30% based on ensemble members showing light or no rain.

- Seasonable and dry for the end of next week

The back door cold front is expected to clear southward through the area by Thursday. This will usher in cooler and much drier air from the NE. The upper ridge and a building sfc ridge will then dominate the weather over the state Thursday and beyond. Temperatures will be near average levels with almost no rain chances.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 650 AM EDT Sat May 23 2026

Rain has now arrived at all terminals. IFR is in place along the I-94 terminals with MVFR to VFR further north. The northern terminals will see the IFR move in within the first few hours this morning. IFR is then expected to rule the rest of the period. Rain ends this afternoon from West to East, but low level moisture gets trapped in. Then tonight as temps cool and winds go light, low clouds will lower and fog will develop with the moist air mass in place.

MARINE

Issued at 246 AM EDT Sat May 23 2026

As we thought, there were a few gusts that touched the wind criteria of a SCA yesterday and last evening. Not quite frequent enough to need a headline with offshore flow and small waves. The offshore will continue today, and will diminish as the pressure gradient weakens.

After this morning, we will be entering a much quieter pattern with no bigger systems on the horizon. That translates to weaker winds, and no headlines likely for the next week.

GRR WATCHES/WARNINGS/ADVISORIES

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