A severe thunderstorm watch is issued by the National Weather Service when the weather conditions are such that a severe thunderstorm (damaging winds 58 miles per hour or more, or hail three-fourths of an inch in diameter or greater) is likely to develop. This is the time to locate a safe place in the home and tell family members to watch the sky and listen to the radio or television for more information.
A severe thunderstorm warning is issued when a severe thunderstorm has been sighted or indicated by weather radar. At this point, the danger is very serious and everyone should go to a safe place, turn on a battery-operated radio or a television, and wait for the storm to pass.
Estimating Distance From A Thunderstorm: Because light travels much faster than sound, lightning flashes can be seen long before the resulting thunder is heard. Estimate the number of miles you are from a thunderstorm by counting the number of seconds between a flash of lightning and the next clap of thunder. Divide this number by five.
Important: You are in danger from lightning if you can hear thunder. Knowing how far away a storm is does not mean that the danger is only when the storm is overhead.
The 30/30 Lightning Rule: Go inside or get in your vehicle if, after seeing lightning, you cannot count to 30 before hearing thunder. Stay inside 30 minutes after hearing the last clap of thunder.
Winds: Summer storm formations always bring winds with them here, even though they sometimes drop little rain. Winds of anywhere from 15-40 mph are common, and up here in the mountains, they seem to blow in every direction. If you or your children are outdoors, avoid as much as possible being near dead or dying trees when winds are strong. These trees can fall without warning anyway, and high winds only increase the potential for tree falls.