National Weather Service Marquette MI
9:45 AM Sunday March 18.
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, a weakening 30.0 inch trough passed over far eastern lake superior this morning. a 30.5 inch high centered over northern manitoba will extend a 30.1 inch ridge into the upper great lakes late today. early next week, a 29.4 inch low will weaken as it moves across the mid mississippi valley, with a 30.4 inch high traversing slowly through ontario. lake superior will be sandwiched between these two systems monday and tuesday, and the high will extend a 30.3 inch ridge southward over our area on wednesday and thursday.