Assessment of wind speeds based on damage observations from the Angus (Ontario) Tornado of 17 June 2014

A tornado occurred in Angus, Ontario, during the late afternoon hours of 17 June 2014. The authors conducted a damage investigation on the morning following the storm. The damage indicators support the classification of the tornado as an EF-2 on the Enhanced Fujita Scale, including the observation of several complete roof failures of recently-constructed, wood-frame houses. Most of the damage to residential homes was contained along two streets, with the tornado appearing to have gone down the backyards between the two. In total, 101 houses were observed to have sustained some level of damage. The evidence suggests that the quality of construction likely affected the performance of failed roofs. A detailed fragility analysis was conducted to assess wind speeds associated with these failures of the roof-to-wall connections. An overturned and lofted box truck provided the opportunity to correlate this failure with adjacent, repetitive failures of roof sheathing, shingles, and garage doors. </jats:p

Observational Evidence For The Impact of the Lake Breeze Circulation on Ozone Concentrations in Southern Ontario

Very rapid increases in the concentrations of ozone and ozone precursors, in the late afternoon, have been observed at a rural and an urban site in southern Ontario. Ozone concentration increases of 30 ppbv in a few minutes have been observed. These increases occur simultaneously with the arrival of a Lake Ontario lake breeze front as identified from meteorological measurements and visible satellite imagery. This indicates that polluted air masses from over Lake Ontario are being transported inland by the lake breeze. Aircraft measurements of ozone, NOx, and hydrocarbons show such an air mass moving inland. Chemical measurements at the sites show that the polluted air masses are not of local origin, but are of similar age to those regularly encountered in rural area