Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
STORMS A tornado is a violently rotating column of air extending from a thunderstorm to the ground Change in wind direction Increase in wind speed Increasing height Rising air within a thunderstorm Tornado damage is measured by the Category Damage Wind F0 light 40–72 mph F1 moderate 73–112 mph F2 significant 113–157 mph F3 severe 158–206 mph F4 devastating 207–260 mph F5 incredible 261–318 mph Where do most tornadoes hit in the United States? In the United States, the area where the tornadoes hit the most is called Tornado Alley. The states which are in the tornado alley are: Danger! Texas Nebraska Colorado Iowa Illinois Indiana Missouri Arkansas Tornadoes! 5 What is a hurricane? • Violent cyclonic storm that develops in the tropical region • Wind speeds http://earthobservatory.nasa.gov/ are > 74 mph Source: Newsroom/NewImages/images.php3?img_id=680 Rotation and Pressure In which direction does a hurricane rotate? COUNTERCLOCKWISE Is the barometric pressure inside the hurricane high or low? LOW What conditions must be present for a hurricane to develop? Source: http://lwf.ncdc.noaa. gov/oa/reports/fran/fran.html 1. Warm ocean temperatures (>80˚ F) up to 60m deep 2. Little to no wind shear 3. Low pressure system at least 5˚ North or South of Equator 4. Rotation caused by winds What is the major source of energy fueling a hurricane? Heat Energy evaporating from the ocean surface Source: http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/hyd/evap.rxml Hurricane Anatomy Source: http://hurricanes.noaa.gov/prepare/structure.htm By what two factors is hurricane strength measured? Wind Speed Barometric Pressure What is the Scale Used to Categorize Hurricanes? Saffir-Simpson Scale Category Max Wind Speed (mph) Min. Surface Pressure (mb) Storm Surge m (ft) 1 74-96 > 980 1-1.7 (3-5) 2 97-111 979-965 1.8-2.6 (6-8) 3 112-131 964-945 2.7-3.8 (9-12) 4 132-155 944-920 3.9-5.6 (13-18) 5 > 155 < 920 > 5.7 (>19) Source: http://kids.earth.nasa.gov/archive/hurricane/saffir-simpson.html Thunderstorms and Rising Air • Thunder storms are started when air rises, cools and starts to loose its moisture. • T-storms are caused by rising humid air along either a warm or cold front • The greater the temperature differences, the more quickly the storm forms • T-storms are rather short-lived, usually the cycle lasts an hour or less 3 parts to a T-storm 1. Formation – rising air expands & cools; condensation occurs, clouds form 2. Mature – precipitation/bad weather 3. Dissipation – clouds disappear 1. A severe snowstorm with strong winds and poor visibility 2. Winds must exceed 56km (35 mi) per hour 3. Temperature must be -7 degrees celsius or lower When do Blizzards Occur • Blizzards occur anytime between late fall and early spring. How do Blizzards Form 1. When colder air meets warmer air and begin to twist. 2. Some type of precipitation must be present in the clouds. 3. Must be a combination of freezing temperature and heavy winds. Where Do Blizzards Occur Blizzards are most common in the: 1. 2. 3. 4. Northern Mississippi Basin Central Part of Canada Russia Central Great Plains