textproduct: Grand Rapids

KEY MESSAGES

- Frost/Freeze Next Couple Nights

- Rain and Thunderstorm Chances Tue-Wed and Late Week

DISCUSSION

Issued at 310 PM EDT Sun May 10 2026

- Frost/Freeze Next Couple Nights

Temperatures this morning were a little colder than forecast under crystal clear skies. Tonight and Monday night will again have frost/freeze potential, widespread in Central Michigan and in the typically colder areas farther south. The NBM mean low temperatures for tonight have trended slightly warmer the past couple cycles, but still plenty cold to maintain the threat of impacts. Confidence in the southern frost threat tonight is just a little lower due to patches of midlevel clouds that should linger later in the night. Another chance of frost is possible in Central Michigan Wednesday night before the larger pattern breaks toward being warmer.

- Rain and Thunderstorm Chances Tue-Wed and Late Week

An Alberta Clipper low pressure system sliding through the region Tue-Wed will bring rain showers starting Tuesday morning. Elevated instability will increase later in the day Tuesday then persist into early morning Wednesday, so the thunderstorm chance will be confined to that time frame. The amount of instability looks to be fairly meager and the lower atmosphere will tend to be stable, thus reducing the chance of severe weather.

The cooler-than-normal pattern so far this month will trend warmer late in the week with the demise of the Greenland blocking high and Quebec low. The return of warmer temperatures and better moisture along with progressive shortwave troughs over the region will result in thunderstorm chances Friday and through the weekend to early next week. Members within each global ensemble system are not settled on which particular day or days are most favored at this time.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 143 PM EDT Sun May 10 2026

VFR conditions are highly likely at all terminals through 00Z this evening (95 percent chance) and through 06Z tonight (90 percent chance). Wind gusts mostly from the west and northwest are expected to diminish around 00Z this evening with winds eventually becoming light to calm. A cold surface airmass early Monday morning could result in the colder air draining to lower elevations, resulting in light winds having a direction more associated with local topography than with synoptic forcing.

MARINE

Issued at 310 PM EDT Sun May 10 2026

Expecting 1 to 3 ft waves through Monday, then a small craft advisory will likely be needed Tuesday as south winds strengthen to 30 knots (perhaps approaching gale force near the Sable points). Hazardous conditions with northwest winds will continue into Wednesday.

GRR WATCHES/WARNINGS/ADVISORIES

MI...Freeze Warning from midnight tonight to 8 AM EDT Monday for MIZ037>040-043>046. Frost Advisory from midnight tonight to 8 AM EDT Monday for MIZ050>052-056>059-064>067-071>074. MARINE...None.