Tools for Predicting Weather

Predicting Weather  Observation: process of watching and noting what occurs.  Prediction: proposed explanation based on reasonable observations of prior events.  Forecast: predicting expected weather trends by examining and analyzing available weather data.  Measurement: collection of quantitative data made by comparing a quantity with a standard unit. In science, the units are metric.

Thermometer  A thermometer is a weather tool used to measure the temperature, a measure of the average kinetic energy of a substance..

Wind Vane  Wind is the horizontal movement of air caused by heating from the sun and rotation of the planet.  Wind Vanes are tools used to measure wind direction.

Anemometer  An anemometer is a weather tool that measures wind speed in MPH.

Wind Chill  Wind Chill refers to the additional cooling effect resulting from wind blowing on bare skin. It is the temperature the body "feels" for a certain combination of wind and air temperature.  This is similar to Heat Index which combines air temperature and relative humidity.

Barometer  Barometers are used to measure air (barometric) pressure, or the force exerted on the Earth’s surface by overlying air.

Barometer  High pressure = light wind & clear skies  Low pressure = windy & overcast; cyclonic storms form

Hygrometer  A hygrometer is a weather tool used to measure humidity, or water content of a gas.  Maritime air masses have a higher humidity than continental air masses.

Hygrometer  Dew point is the temperature to which a given volume of humid air must be cooled, at constant barometric pressure, for water vapor to condense. Condensed water is called dew.

Rain Gauge  A rain gauge is a weather tool used to collect rain.  Using measurements on the side of the rain gauge, you can see how many centimeters it rained.

Upper Level Data  Surface weather data is important, but the weather that we experience is largely due to changes that occur high in the troposphere  Meteorologists gather weather data at heights of up to 30,000 m above the surface using ceilometers (to measure cloud height), weather balloons (measure temperature, air pressure, and humidity), Doppler radar (to measure rainfall and wind speed, especially during storms, and satellite imagery (to track clouds and precipitation)Doppler radar