Anatomy of thunderstorm
It’s near the end of spring and many areas have already seen more thunderstorms in 2007 than in all of 2006. Last Monday, much of the Idaho Panhandle, including Coeur d’Alene, experienced one of the largest thunderstorms in recent memory. That storm had an incredible number of lightning strikes and lasted for more than two hours. Considerable damage was seen throughout the region.
Lightning is simply a discharge of electricity, or a giant spark. It can take place between clouds or between a cloud and the ground. Lightning results from various charge lead separations. The first stage of a flash of lightning brings down a negative charge of electricity from the cloud base which is met near the ground by a return stroke that takes a positive charge upward along an already formed channel or pathway.
Additional leads and returns may occur, but the duration of a particular lightning flash is about one-fifth of a second. The rapid expansion of the super-heated air at more than 50,000 degrees Fahrenheit produces an explosive shockwave that we hear as thunder. The typical bolt of lightning is actually four times hotter than the surface of the sun.
A cloud-to-ground strike can be 2 to 10 miles long. The voltage is an incredible 100 million to 1 billion volts. Around the Earth, there are 100 lightning strikes per second, or 8,640,000 times a day. In the United States, there are approximately 100,000 thunderstorms each year. Most of them occur east of the Rockies, but every state usually sees this phenomenon each year. The normal number of days with thunderstorm activity in the Inland Northwest is 11.
Lightning is the most dangerous and frequently encountered weather hazard that people experience. It is the No. 1 cause of storm-related deaths, and Americans are twice as likely to die from lightning than from a hurricane, tornado or flood. Twenty percent of all lightning victims die from the strike while 70 percent of survivors will suffer serious long-term effects. Many survivors of lightning strikes report immediately before being struck that their hair was standing on end, and they also had a metallic taste in their mouth.
Damage costs from lightning are estimated at $4 billion to $5 billion each year in the United States And, there are more than 10,000 forest fires caused by lightning. Many large fires in the summer and early fall in the Inland Northwesthave been caused by dry thunderstorms that generated numerous lightning strikes.
If you find yourself in a thunderstorm, get inside as soon as possible. Stay way from large windows and metal doors. Do not use a land-line telephone as electricity can literally travel through phone lines. Do not bathe or shower and unplug all TVs, VCRs and sensitive electronic appliances.
As for the near-term weather outlook, there should still be warmer temperatures along with scattered showers and a few thunderstorms into next week. Hot and dry weather should arrive by late this month or early July. Another round of big heat is also expected in late July in early August. Temperatures may soar into the 90s and near the 100-degree mark during these times.
Most of July, August and early September will likely be quite warm, even hot at times, with limited precipitation, mostly resulting from scattered afternoon and evening thunderstorms.
The fall may turn wet and cool again, especially if the current La Nina sea-surface temperature event in the Pacific Ocean waters gains strength or even maintains its current level of intensity off the West Coast of South America. Stay tuned.