226 FXUS63 KGRR 012323 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 723 PM EDT Fri May 1 2026 .KEY MESSAGES... - Freeze Expected Tonight - Cool with Occasional Showers Next Week && .DISCUSSION... Issued at 247 PM EDT Fri May 1 2026 - Freeze Expected Tonight We have issued a Freeze Warning for tonight for the entire forecast area. A cold airmass is in place with sfc dew points in the 20s and model soundings, including the HRRR, showing enough drying to indicate stratus should diminish this evening, although clouds could return late tonight. Still, we expect temperatures to fall below freezing across all areas, even near Lake Michigan. If skies stay clear fore several hours, we expect temperatures to fall into the 20s. - Cool with Occasional Showers Next Week Upper troughing will prevail through next week across the Great Lakes region, bringing mostly cooler than normal temperatures and occasional showers as shortwave troughs pass through in fast northwest flow. Thunder along with gusty winds is possible on Monday afternoon and evening as a cold front moves through. The front stalls across the Ohio Valley with a surface low tracking northeast along the front. At this point it looks like the orecip shield stays east of Lower Michigan. Even so, showers are possible on Thursday as steep lapse rates would support diurnally-enhanced updrafts and it is cold enough at mid and low levels for them to produce graupel. Frost/freeze conditions will also persist for Sunday morning and much of next week. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 718 PM EDT Fri May 1 2026 Much of Lower MI is covered in bkn-ovc vfr stratocu, beneath an upper low/trough. This trough will keep clouds at the terminals throughout the period. Some clearing is trying to develop over eastern WI. As that moves east, we may see cigs scatter at MKG and perhaps GRR later tonight. Expect a sct-bkn VFR deck Saturday as the trough axis and cold temperatures aloft keep lapse rates sufficiently steep for stratocu development. && .MARINE... Issued at 247 PM EDT Fri May 1 2026 Winds and waves increase on Sunday and unless the forecast changes appreciably a SCA will be needed for Sunday and Monday. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Freeze Warning from midnight tonight to 9 AM EDT Saturday for MIZ037>040-043>046-050>052-056>059-064>067-071>074. MARINE...None. && $$ DISCUSSION...Ostuno AVIATION...04 MARINE...Ostuno

NWS GRR Office Area Forecast Discussion