textproduct: Grand Rapids

KEY MESSAGES

- Thunderstorm Potential this Afternoon/Evening

- Quiet Weather the rest of the Week

DISCUSSION

Issued at 217 AM EDT Wed May 27 2026

- Thunderstorm Potential this Afternoon/Evening

Hi res models are picking up on the potential for afternoon convection along the southward moving cold front this afternoon and evening. The potential has been indicated for a few days by model soundings showing 500 to 1000 J/kg of CAPE across the southeast forecast area. Limiting factor appears to be a lack of deep moisture as seen in forecast soundings, but this also indicates a strong downdraft potential with a pronounced dry wedge beneath the LCL.

For POPs this afternoon, the Hires ARW forecast POPs were smoothed out and the timing, which is a bit later than the NBM, was followed. Expect the showers and storms to be weakening with the loss of insolation as they depart the SE zones by around 9 pm. Isolated severe winds and hail are possible with any sustained updrafts.

- Quiet Weather the rest of the Week

High pressure building in on Thursday with generally dry northwest flow regime into the weekend as the Omega block across North America finds the Great Lakes in between the upper high over central Canada and a trough across eastern Canada into the NE CONUS. Another cold front moves through from the north on Saturday but limited moisture suggests chance for any rain will be less than 20 percent with that fropa.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 217 AM EDT Wed May 27 2026

VFR conditions will prevail through Wednesday evening except for isolated MVFR and even a low chance of brief IFR in thunderstorms late this afternoon into early evening. Strong gusty surface winds greater than 30 knots and hail are possible with these storms but coverage should be limited and most likely between LAN and JXN around 21Z to 01Z.

MARINE

Issued at 217 AM EDT Wed May 27 2026

Still looks like a SCA will be needed Wednesday night into Thursday evening with a tight surface pressure gradient as a high builds in producing north winds to 25 knots.

GRR WATCHES/WARNINGS/ADVISORIES

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