Presentation on theme: "Mrs. Passells Weather Test Review revised 2.9.14 The test will assess your understanding of clouds, precipitation, water cycle, fronts, high & low pressure."— Presentation transcript:
Mrs. Passells Weather Test Review revised 2.9.14 The test will assess your understanding of clouds, precipitation, water cycle, fronts, high & low pressure areas, weather maps, weather instruments, heat transfer & storms. It will not cover the layers of the atmosphere or air as a mixture.
WHOS STUDYING THE WEATHER? Besides Mrs. Passells students? METEOROLOGISTS! TV weatherpersons usually dont have a degree in meteorology, the study of weather.
CLASSIFYING TYPES OF CLOUDS Clouds are classified by their shapes and their altitude. You will need to be able to identify stratus, cirrus, and cumulus clouds and describe the kind of weather each one brings.
COMMON TYPES OF CLOUDS.
STRATUS CLOUDS Stratus clouds are not individual units. These are the lowest clouds. They produce widespread rain or snow that may last days longer than a thunderstorm. Fog is a stratus cloud close to the ground.
CUMULUS CLOUDS Puffy clouds like the ones you drew in first grade Fair weather clouds
CUMULONIMBUS CLOUDS Bring heavy rains, lightning, thunder May bring violent weather Also called Thunderheads http://www.crh.noaa.gov/images/ilx/swop/clouds.jpg
CIRRUS CLOUDS High altitude, thin clouds Wispy, like feathers Made of ice crystals Sometimes called mares tails http://www.met.tamu.edu/class/Metr304/Severedir/CirrusCl ouds.jpg
FRONTS An AIR MASS is the large body of air that has the characteristics of the land over which it develops. The whole air mass will have the same temperature, pressure and humidity. A FRONT is the place where two air masses meet.
SYMBOLS FOR FRONTS think of cold pointy icicles think of the warm sun rising in the east - not on the test think of a stationary exercise bike - - youre pedaling but not going anywhere!
MOVEMENT OF FRONTS The front is moving in the direction of the points or half-circles. Stationary fronts are stationary so they are not moving!
MOVEMENT OF FRONTS Remember that COLD AIR IS MORE DENSE than WARM AIR. Because WARM AIR is less dense, it doesnt push under the cold air. It rises up over it. When the COLD AIR approaches warm air, it pushes under the warm air. Think of a cotton ball (less dense warm air) approaching a stone (more dense cold air). Cant push under, got to go over!
WARM FRONT Remember that warm air is less dense than cold air so it will slide up over the more dense cold air.
WARM FRONT The weather is rainy or snowy as the front approaches and the temperature starts to rise. Warm Front. Image Credit: NOAA; http://tinyurl.com/c3o9gtu
COLD FRONT A cold front pushes under the less dense warm air. Violent storms can occur.
STATIONARY FRONT The WARM FRONT and COLD FRONT come together along a stationary front. The weather will be unsettled and for a few days.
WATER CYCLE/ HOW CLOUDS FORM.
During CONDENSATION the moisture that has evaporated and becomes water vapor cools as it rises in the atmosphere. The water vapor condenses to form clouds. Water drops that form in the clouds fall back to earth as precipitation. WATER CYCLE FOR KIDS Think about a cold window. If you breathe on the window, your warm breath will form water droplets on the cold surface.
PRECIPITATION : RAIN & SNOW Rain – liquid water; most common form of precipitation Snow - - Just like rain except it passes through layers of freezing air as it returns to Earth
PRECIPITATION : SLEET, HAIL & FREEZING RAIN Sleet - - rain passes through cold air close to the ground Hail - - ice crystals rise & fall within the thunder- cloud; when they become too large, they fall to Earth Freezing Rain – regular land that freezes when it lands on surfaces that are 32 º or lower
ISOBARS These lines connect places that have equal air pressure. The closer together the lines are, the stronger the winds will be.
HIGH PRESSURE AREAS High pressure is indicated with an H The weather will be fair with clear skies & maybe some puffy cumulus clouds..
HIGH PRESSURE = rising barometric pressure.
LOW PRESSURE AREAS Low pressure systems are marked with an L. Cloudy weather & precipitation is found in low pressure areas. The center of all storms, including hurricanes, are low pressure areas.
LOW PRESSURE = falling barometric pressure.
WINDS Energy from the sun causes uneven heating of Earths surfaces. This causes winds. http://astronomy.nmsu.edu/tharriso/ast110/convection3.gif
WINDS Air moves from areas of high pressure to areas of low pressure.
HURRICANE OR TORNADO? Tornadoes are very different from hurricanes even though they are windstorms that cause much destruction. A hurricane is a large low pressure system that covers a wide area. A tornado is a a more localized storm that lasts a shorter amount of time. http://www.phe.gov/Preparedness/planning/playbooks/hurricane/Page s/default.aspx http://graphics8.nytimes.com/images/2013/05/24/us/Tornado1/Tornado1-superJumbo.jpg
HURRICANES These storms form along the warm tropical waters near the equator. http://spaceplace.nasa.gov/hurricanes/
HURRICANES If you could slice into a tropical cyclone, it would look something like this. The small red arrows show warm, moist air rising from the ocean's surface, and forming clouds in bands around the eye. The blue arrows show how cool, dry air sinks in the eye and between the bands of clouds. The large red arrows show the rotation of the rising bands of clouds.(http://spaceplace.nasa.gov/hurricanes/)http://spaceplace.nasa.gov/hurricanes/
TORNADO A tornado forms from a thunderstorm. Warm moist air meets cool dry air. Changes in wind speed and direction at different altitudes cause the spinning to begin.
DROUGHT Drought occurs when there is little or no precipitation for a long time. http://en.wikipedia.org/wiki/2012–2013_North_American_drought
HOW LARGE BODIES OF WATER AFFECT WEATHER Large bodies of water hold their heat longer than areas of land far from water. 56 ° 68 °
WEATHER INSTRUMENT: ANEMOMETER *measures the speed of the wind; strong winds cause the cups to spin faster
WEATHER INSTRUMENT: BAROMETER measure air pressure in inches or mercury or millibars
WEATHER INSTRUMENT: HYGROMETER or PSYCHROMETER measures the humidity (the amount of moisture in the air)
WEATHER INSTRUMENT: WEATHER VANE or WIND VANE shows the direction the wind is blowing Nevit Dilmen
WEATHER INSTRUMENT: THERMOMETER measure the temperature
WEATHER INSTRUMENT: RAIN GAUGE measure the amount of rainfall
How Does Air Pressure Change With Altitude? As you climb higher up the mountain the air pressure is less than down at sea level and it becomes more difficult to breathe.
HEAT TRANSFER: CONVECTION When air or water is heated, the molecules move faster and farther apart, reducing their density and causing them to rise. Cooler air or water molecules move more slowly and are denser than warm air or water. The cold air sinks down. When it warms up again, it will rise again. Remember the rising air helps sailplanes & eagles to soar.
HEAT ENERGY TRANSFER: CONDUCTION http://commons.wikimedia.org/wiki/File:Cup_for_Heat_Conduction_2010-08-17.png Conduction is heat transfer by direct physical contact. The object has to be touching the heat source! Conduction can happen in solids, liquids and gases. Example: An ice cube will melt in your hand because the heat from your hand is absorbed by the ice.
HEAT TRANSFER : RADIATION Radiation is energy transfer through empty space. It travels in the form of light waves. Sunlight is a form of radiation.