Measuring the Weather

The Measurement and Recording of Local Weather Aims: 1) To understand how weather is recorded and the limitations of the methods used. 2) Appreciate how weather data is used to forecast future weather.

What is weather data? Data Type Units used Instrument Used Temperature °C or °F Thermometer Precipitation mm or inches Rain Gauge Pressure Mb or Hp Aneroid Barometer Wind Speed Kts / Km/h / Mph / Beaufort Scale Anemometer Wind Direction NESW Wind Vane Sunshine Hrs / Mins Sunshine Recorder Humidity % Wet and Dry bulb Thermometer

Weather information is also obtained from: Buoys floating in the sea Weather balloons Land based recording stations (some are equipped with RADAR) Satellite data Ships and aircraft making reports as they move along their routes

Buoys floating in the sea

Weather balloons

Land based recording stations (some are equipped with RADAR)

Satellite data

Ships and aircraft making reports as they move along their routes

In a little more detail: http://www.hko.gov.hk/aviat/edu_inst/inst_e.htm

http://www.hko.gov.hk/aviat/edu_inst/inst_e.htm

What’s the data used for? Forecasting. Definition? Helped by: Large quantities / past data ICT improvements

Forecasting. Definition?

Helped by:

Large quantities / past data

ICT improvements

Presentation of Weather Data Synoptic charts. These are isoline maps that show pressure differences allowing forecasters to see such things as depressions and anticyclones for a particular time. They also show wind speed and direction.

Synoptic charts. These are isoline maps that show pressure differences allowing forecasters to see such things as depressions and anticyclones for a particular time. They also show wind speed and direction.

RADAR Images . These are pictures created from RADAR scans showing cloud formations

These are pictures created from RADAR scans showing cloud formations

Increasingly, computers are used to display a variety of data sometimes as time lapse (or sometimes real time) images. Click here or on the RADAR picture below to see a time lapse animation for the UK. Click here is to see Typhoon Selma in Australia

Click here or on the RADAR picture below to see a time lapse animation for the UK.

Satellite Images Similar to RADAR images but the benefit of satellite images is the fact that temperature differences can also be shown. Time lapse and real time viewing is also possible using these images.

Similar to RADAR images but the benefit of satellite images is the fact that temperature differences can also be shown. Time lapse and real time viewing is also possible using these images.

Computer Models These are used to forecast likely weather behaviour. Data is inputted into the model which is loaded with detailed information relating to weather patterns and behaviour. Based on the data inputted , the model will forecast likely weather conditions for a particular place at a particular time.

These are used to forecast likely weather behaviour. Data is inputted into the model which is loaded with detailed information relating to weather patterns and behaviour. Based on the data inputted , the model will forecast likely weather conditions for a particular place at a particular time.

Precipitation

Temperature

HUMIDITY

Cloud Height Ceiliometer

Ceiliometer

VISIBILITY

Sunshine

Cloud Type

Wind Direction

Wind Speed

Forecasting Information about the forecasting process: http://www.bom.gov.au/lam/forecast.shtml Seeing forecasting in action: Video: 4 Days in August.

Information about the forecasting process: http://www.bom.gov.au/lam/forecast.shtml

Seeing forecasting in action:

Video: 4 Days in August.