Gathering and Analyzing Weather

 Surface Data ◦ Temperature  Thermometer  Enclosed liquid that expands or contracts  Measured in o C or o F ◦ Air Pressure  Barometer  Measured in millibars of mercury (mb)

 Wind Speed  Anemometer ◦ Cupped arms that rotate  Relative Humidity  Hygrometer ◦ Wet bulb/Dry bulb thermometers ◦ Use a chart & finding the difference of the 2 (pg 916) ◦ If you have a Dry bulb reading of 10 o C and a wet bulb reading of 14 o C, what is your relative humidity? ◦ 55%

 Rain Gauge  Amount of Rain Fall  Ceilometer ◦ Measures the height of clouds  It’s important for meteorologists to take data at the same time everyday to give accurate forecasts

 Radiosonde ◦ Weather Balloon ◦ Package of sensors that measures Temp, pressure, and humidity

 Weather Radar ◦ Radio Detecting And Ranging ◦ Transmits electromagnetic waves which bounce off surfaces ◦ Meteorologists can see images that appear  Doppler Radar ◦ Measures the change in frequency with movement ◦ Used to interpret speed of storms

 Satellites ◦ Taking high altitude pictures of storms  Infrared ◦ Monitors the temperature of clouds and storms ◦ Temp is important because it helps establish potential for a severe storm

 After weather is observed and gathered, data is plotted  S.M. is the weather data for a particular site  Use symbols to represent weather

 Isopeths: used to plot the data ◦ Lines that connect points of equal values ◦ Isobars  Lines for Equal Pressure ◦ Isotherms  Lines for Equal Temp  Distance between lines can determine differences ◦ Isobars  Lines close together indicate large pressure difference over a small area ◦ Causing strong winds

 Digital Forecasts Digital Forecasts ◦ Relies on numerical data ◦ Atmosphere can act like a fluid (pressure, temp, density) ◦ Use of technology can speed up process

 Analog Forecast ◦ Current weather patterns compared to years past ◦ Look for an analogous pattern over all levels of atmosphere and large area  *drawback to analog forecasting* ◦ Monthly and Seasonal patterns

 All things in nature can determine weather (mountains, cities, rivers, valleys)  Hard to be reliable for long term changes  Hourly Forecast ◦ Accurate due to small scale weather features ◦ Rain, clouds, Temp

 1-3 Day Forecasting ◦ Behavior of larger surface & Upper-level features  low pressure system ◦ Somewhat predict precipitation or dryness ◦ Not necessarily the temp or sky condition  4-7 Day Forecasting ◦ Predicting based on circulation patterns in troposphere ◦ Based on Analogous conditions