Weather Forecasting & Maps

- Meteorologists make forecasts based on models that are produced by supercomputers which perform a large amount of calculations based upon a selection of equations.

- These models use information from:

- 1) Surface Observations (weather stations – barometer, anemometer, ships, buoys, radar stations)

- 2) Weather Balloons (carries radiosondes)- 3) Satellite Information (takes pictures)

Hurricane Sandy – Ensemble Models

Examples of what supercomputers look like…

Currently, the average model uses cubes with side lengths of 50 km

Weather Balloons are sent out twice a day around the world at exactly the same time 0:00 and 12:00 UTC (8 am and 8pm our time)

Radiosonde: a specialized piece of equipment that collects data such as temperature, humidity, pressure, elevation, wind-direction and speed.

Anemometer

- An instrument that measures the wind speed. (km/hr)

Barometer

- A scientific instrument used to measure atmospheric pressure. (mb)

LOW – is a sign of inclement/bad weatherHIGH – is a sign of fair weather

Furthermore, the faster the pressure drops, the more intense the storm is likely to be.

More Terminology

Radar Imagery – uses radio waves to detect, locate, and measure the amount of precipitation in the clouds.

Satellite Imagery – pictures taken from space that are used to observe clouds and in particular storm systems

** Very useful for hurricanes … (70 % of earth’s surface is water) …otherwise very difficult to gather surface information.

Infrared Satellite ImageryLow clouds – (warmer and emits more infrared energy)…denoted grayHigh clouds – (colder and emits less infrared energy)…denoted white, or orange

Result: can easily pick out stormy weather (zones of thick, heavy clouds)

Front – the leading edge of an air mass

Isobars – lines on a weather map of equal pressure (the contour lines of weather maps)

Weather map of a storm from 1998.

Weather Sources.

1) Environment Canada

Visit: http://www.weatheroffice.gc.ca/canada_e.html

2) The Weather Network

Visit: http://www.theweathernetwork.com/

3) Surface observation map

Visit: http://meteocentre.com/analyse/map.php?date=0&lang=fr&map=AmeriqueduNord&size=large

4) Computer Model Forecasts

Visit: http://wxforecaster.com/ncep/java/new/test/all.html

5) Numerical Weather Model Predictions

http://spotwx.com/

6) Accu Weather

http://www.accuweather.com/en/ca/canada-weather

Weather Forecast Homework activity

1) Choose a three day period.

2) Create your own weather forecast using the resources that I have provided you with. Record the time when you made the forecast. Also, record the weather source(s) that you relied on the most. Do not update it any! ** Do not directly copy a weather forecast on a particular site. Make it your own!

3) After each day, write a short summary of how well you forecasted the weather. (temperature, winds, precipitation, etc.)

4) Conclusion. At the end, summarize your experience as a meteorologist. Do you understand their job responsibilities more? Were there models that you used that seemed to be more accurate than others? Were your short term forecasts more accurate than your long range forecasts? Why or why not?

Top of a thunderstorm cloud. (cumulonimbus)

Weather map of a storm from 1993.

** The closer the isobars – the faster the wind speed!