Presentation on theme: "Weather is the state of the atmosphere at any given time or place."— Presentation transcript:
1 Weather is the state of the atmosphere at any given time or place.
2 ClimateClimate is the average weather conditions that occur in a region over a long period of time.
3 How is weather measured and described? Temperature (0C)Precipitation (mm for rain) (cm for snow)Atmospheric Pressure or Air Pressure (kPa)Wind (km/hr)Relative Humidity (%)Clouds (type)U.V. Sunlight Rating (1 low to 11 extreme)
4 Atmospheric PressureThe amount of force pushing on you due to the weight of the air.High and Low Pressure SystemsWhen the air is compressed it is under “high pressure”.Weather forecasters measure air pressure with a Barometer.Standard Atmospheric Pressure is kPa
5 Atmospheric Pressure and Weather Air pressure can tell us about what kind of weather to expect as well.If a high pressure system is on its way, you can expect cooler temperatures and clear skies.If a low pressure system is coming, then look for warmer weather, storms and rain.
6 WindWind is air that is moving from a high pressure system to a low pressure system.The spinning of the Earth also creates wind (The Coriolis Effect). This causes the prevailing westerly winds in North America.
7 Clouds Most clouds are associated with weather. They are divided into groups based on the height of the cloud’s base about the Earth’s surface.
8 High Clouds (“Cirr”) 5 000 – 13 000m made of ice crystals due to the cold air in the upper skynot really associated with daily weather
9 Middle Clouds (“Alto”) Altostratus – covers whole sky, blue-gray appearance. They usually form ahead of storms with continuous rain or snow.Altocumulus – form in groups (grayish-white). They are about as wide as your thumb when you hold up your hand at arm’s length. If you see them on a warm humid morning, expect thunderstorms by afternoon.
10 Low Clouds (“Strat”) Surface – 2 000m Stratus – look like a fog that doesn’t reach the ground. Light mist or drizzle is sometimes associated with these clouds.Stratocumulus – are low, lumpy and gray. They can look like cells under a microscope.Nimbostratus – dark gray with a “ragged” base. They are associated with continuous rain or snow.
11 Clouds with Vertical Growth (“Cumu”) Surface – mThese clouds grow high up into the atmosphere rather than spreading out.Cumulus – cloud puffs that are about the size of your fist when you hold up your hand at arm’s length.Cumulonimbus – thunderstorm clouds