Thunder Bay Weather: Gusty Winds and Showers Give Way to SunshineTHUNDER BAY – Thunder Bay begins Tuesday with mostly cloudy skies, strong west-northwest winds and a chance of additional showers. Thunder Bay Three-Day ForecastTuesday, Aug. 4Morning showers will end before mainly cloudy skies settle over the city. West winds will reach 30 km/h, gusting to 50 km/h. West winds of 20 km/h, gusting to 40 km/h, will become light. West winds will increase to 20 km/h, gusting to 40 km/h, late in the morning.