Seasonal temperatures have prevailed during the last seven days. The last week also featured a number of thunderstorms. Most of these were of the “pop-up” variety, formed by daytime heating in the afternoon and generally of brief duration. Today and tomorrow promise much of the same – pleasant temperatures and scattered thunderstorm activity. Less cloud and warmer temperatures are likely in the following days.
Most of us are quite familiar with classic summer storms – darkening sky, abrupt freshening winds, quickly followed by flashes of lightning. Counting one thousand, two thousand and so on, (one mile for every count) gives us an estimate of how far away the strike was and how fast the storm is approaching. HINT: If you are on the water, it is time to seek safety on land.
Lightning is awe inspiring although the power and consequences can be ferocious. It can convert trees into shrapnel and in an average year starts more than 4,000 forest fires in Canada. Lightning can be fatal, although of the 110 people struck by lightning in Canada in a typical year, about 90 percent survive. However, it is said that most survivors are never the same again.
Lightning travels through the sky at about one thousand feet per second. At 50,000 F (28,000°C), lightning is considerably hotter than the surface of the sun causing air in the immediate vicinity of the strike to expand rapidly. This is immediately followed by compression and creates the sounds that we hear as thunder which travels outwards from the flash.