


Great Lakes Forecast
Issued by NWS
Issued by NWS
759 FZUS63 KDTX 181347 GLFSC Lake St Clair Forecast National Weather Service Detroit/Pontiac MI 947 AM EDT Mon Aug 18 2025 Waves are the significant wave height - the average of the highest 1/3 of the wave spectrum. Occasional wave height is the average of the highest 1/10 of the wave spectrum. .SYNOPSIS...High pressure, 30.30 inches, over Ontario slowly advances east through today. In response, Great Lakes winds ease just slightly as they veer around to the east-southeast. The next low pressure system arrives Tuesday, triggering showers and thunderstorms across the region. LCZ460-182200- Lake St Clair- 947 AM EDT Mon Aug 18 2025 .REST OF TODAY...East winds 10 to 15 knots diminishing to 5 to 10 knots late in the afternoon. Mostly sunny. Waves 2 feet or less. .TONIGHT...East winds 5 to 10 knots. Mostly clear. Waves 2 feet or less. .TUESDAY...Southeast winds 5 to 10 knots. Partly sunny. A chance of showers. A chance of thunderstorms early in the afternoon. Waves 2 feet or less. .TUESDAY NIGHT...Southeast winds 5 to 10 knots backing to the north after midnight. Partly cloudy. A chance of thunderstorms early in the evening. A chance of showers until early morning. Waves 2 feet or less. .WEDNESDAY...North winds 10 to 15 knots increasing to 15 to 20 knots in the evening. Partly cloudy then clearing. Waves 1 to 3 feet. .THURSDAY...Northeast winds 15 to 20 knots. Mostly clear. Waves 2 feet or less. .FRIDAY...South winds 5 to 10 knots. Clear. Waves 2 feet or less. $$ JA Experimental modernized open lake forecast is available online at weather.gov/dtx/glftablesc Graphical marine forecasts are available at weather.gov/greatlakes