Toronto Wind Rose
Much like Detroit and Chicago, the winds in Toronto are driven primarily by the ever changing synoptic forces. In addition, summertime winds in Toronto are often driven by the thermal gradients, as summer temperatures warm up and the lake waters stay cool creating frequent lake breezes. This makes wind prediction important and at times tricky, for sailing events on Lake Ontario. June is the first real month of summer in Toronto. The average day time high temperature is about 23 degrees C (low 70’s F) and June is neither a wet month nor a dry month, with an average of 68mm of rain. Thunderstorms are common as are rapid temperature changes that can be as much as 30 degrees simply depending on if the winds are off the water. However the slightly cooler temperatures in Toronto mean fewer thunderstorms. Toronto has an average of 5 thunderstorms a month (for June), which is a little less than the average of 6 for both Chicago and Detroit. If you have done the other NOOD events this year, the winds on average will be slightly less in Toronto than you have seen in either Detroit or Chicago. As the month of June progresses there are fewer synoptic events (frontal passages), and high pressure often takes hold, creating a predominant SW’ly gradient flow (with a monthly wind speed average of 8 knots). As the high takes hold the thermal gradients and lake breezes also become more important; especially considering that Toronto, like Chicago, is an urban heat island, acting as a magnet for these winds, and allowing lake breezes to last well into the evening. Knowing what forces are driving these winds is of great importance to gaining the edge on your competition. Sailflow.com provides real-time sensors as well as forecast products complimentary through the race period at www.sailflow.com/toronto. In cooperation with North Sails, Sailing Weather Service is offering free precision race forecasts for this event. Sign up at http://na.northsails.com/ew/ew_main.taf
