Storms
What is a storm? A violent disturbance in the atmosphere.
What is a storm? Cause rapid air movement Involves sudden changes in air pressure Cause rapid air movement Conditions that bring one kind of storm in one area often cause other kinds of storms in the same area
A thunderstorm is a small storm often accompanied by heavy precipitation and frequent thunder and lightening. A thunderstorm forms when warm, humid air rises rapidly within a cumulonimbus cloud.
Types of severe storms Thunderstorms Tornadoes Snowstorms Hurricanes
Severe Thunderstorms Torrential Downpours Strong winds at greater than 58 miles per hour Hail ¾ inch diameter (or larger) Frequent lightning
Severe Thunderstorm Watch Issued by National Weather Service This means that conditions are favorable for a thunderstorm Length is multiple hours.
Severe Thunderstorm Warning Issued By Local Weather Service Means a severe storm has been spotted by doppler radar Usually lasts for only an hour
Lightning A sudden spark or energy discharge, caused when electric discharges jump between parts of a cloud, nearby clouds, or between a cloud and the ground. Because a lightening bolt can heat the air near to it close to 30,000 ̊ C, it causes the air to expand explosively. Thunder is the sound of the explosion. Since light travels faster than sound you see lightening flash then you hear thunder.
Properties of a Lightning Temperatures of over 30,000C (much hotter than Sun’s surface) Heated air expands suddenly and explosively making a sound of thunder.
Thunderstorm/Lightning Safety Stay indoors, away from doors and windows. Avoid objects that conducts electricity, such as metal objects and bodies of water. Do not seek shelter under the trees. Do not use phones with cords. Remember: Cars are pretty safe…
Why do we see lightning before we hear thunder? Because light travels much faster than sound.