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Forecasting the WeatherForecasting the Weather

WeatherWeather

• Weather: The daily conditions of a particular Weather: The daily conditions of a particular area: temp, rain, pressure, wind, etc.area: temp, rain, pressure, wind, etc.

• Climate: the measure of weather over a very Climate: the measure of weather over a very long period of time—at least 100 yearslong period of time—at least 100 years

• Meteorology- the science of studying Meteorology- the science of studying weatherweather

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What is a weather What is a weather forecast?forecast?

• Forecast: A prediction of weather over the next 3-5 days.

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What is a meteorologist?What is a meteorologist?• Meteorologist: A person who

observes the atmosphere, collects data, and makes predictions—forecasts—based on the data.

• Meteorologist = weather person

• You know them as weathermen and weatherwomen.

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What do meteorologists measure?What do meteorologists measure?

• Air pressure

• Humidity

• Precipitation

• Temperature

• Wind speed

• Wind direction

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Weather balloonsWeather balloonsPictures courtesy of http://www.srh.noaa.gov/epz/kids/balloon.shtml:Pictures courtesy of http://www.srh.noaa.gov/epz/kids/balloon.shtml:

Weather Weather InstrumentsInstruments

Anemometer

Wind Sock

Thermometer

Barometer

Doppler Radar

Weather Satellite 77

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Weather BalloonsWeather Balloons

• Weather balloons: Carry equipment as high as 30 km above the Earth’s surface

• Measure temperature, air pressure, relative humidity, wind speed, & direction

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ThermometerThermometer

• Thermometer: Used to measure:– air temperature

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BarometerBarometer

• Barometer: Used to measure air pressure

PsychrometerPsychrometer

An instrument used for measuring the An instrument used for measuring the water vapor content of the atmosphere; a type of hygrometer.

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AnemometerAnemometer

• Used to measure wind speed

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Wind SockWind Sock

• Used to measure wind direction

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Wind Vane/Weather VaneWind Vane/Weather Vane

• Used to measure wind direction

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RadarRadar• Used to find location, movement, kind &

amount of precipitation

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Weather SatelliteWeather Satellite

• Orbit the Earth & send information back to Earth; used to track storms, wind speed, humidity, & temperature @ different altitudes

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Collecting & Analyzing Weather Collecting & Analyzing Weather DataData

• 2 groups who gather information:

– National Weather Service (NWS)

– NOAA (National Oceanographic & Atmospheric Administration)

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NWSNWS

• Produce maps based on information gathered from over 1,000 weather stations nationwide

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Station ModelStation Model

• A small circle that shows the location of a weather station

• Surrounding the small circle is a set of symbols & numbers that represent weather data

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Example of a Station ModelExample of a Station Model

Weather Map SymbolsWeather Map Symbols

Cold Front

Warm Front

Occluded Front

Stationary Front

High Pressure

Clear Weather

Low Pressure

Cloudy Weather

Isobars:

Show equal

Lines of

Pressure.

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Cold FrontCold Front

• Represented by triangles on a line

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Warm FrontWarm Front

• Represented by half-circles on a line:

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High PressureHigh Pressure

• Usually brings clear, sunny weather

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Low PressureLow Pressure• Bring rainy weather

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IsobarsIsobars

• Lines that connect points of equal pressure on a weather map

ISOBARS- Certain weather maps allow us to view High and Low pressure systems that control the weather. An isobar is a line connecting locations of equal barometric pressure. Isobar maps show where pressures are relatively high and low, and show us where pressure changes are gradual or dramatic over a distance.

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