booya
31/08/2003, 10:45 PM
We have received a couple of emails from members wanting to know a bit about reading the weather charts. We have gathered some information and links to good pages to read for those who wish to know a little more about weather maps and predicting local swells.
Analysis and forecast charts are developed by scientists with the workable knowledge of algorithms and access to various sources of weather related data. Our knowledge is based on experience with Gold Coast surf and swells and a combined general understanding of reading and interpreting weather analysis and prognostic forecast charts.
Predicting and forecasting swell is not easy to do accurately all the time but a basic understanding of reading weather maps and following the local swells can make anyone a reasonable surf forecaster.
The weather maps surf forecasters are mainly interested in are the mean sea level synoptic analysis and prognostic forecast charts. Thanks to various organizations around the world we also have the added benefit of access to model generated swell forecasts, which have proved to be reasonably reliable and are becoming an integral element of all surf forecasters tools.
Analysis charts represent the real state of conditions using currently recorded weather data. Prognostic or forecast charts represent the future state of conditions formulated from predictions based on the analysis charts and other historic weather data.
Current Analysis Chart for Australia:
http://www.bom.gov.au/weather/national/charts/synoptic.shtml
Tomorrow Morning Quality Controlled Forecast Chart for Australia:
http://www.bom.gov.au/weather/national/charts/24hour_man.shtml
Tomorrow Night Computer Generated Forecast Chart for Australia:
http://www.bom.gov.au/weather/national/charts/24hour_cgen.shtml
Various factors influence the size, speed and direction of swell. The two main things surf forecasters analyse on the weather charts are the High and the Low pressure systems. High pressure systems turn anti-clockwise in the southern hemisphere and form upward air flows. Low pressure systems turn clockwise in the southern hemisphere and form downwards air flows. Low pressure systems are the real swell generating systems.
A great 1 page description by the Bureau of Meteorology about High and Low pressure systems for Australia can be found at the following link. The text and the animated graphics easily explain how they work and how they can work together.
High and Low pressure systems:
http://www.bom.gov.au/lam/Students_Teachers/pressure.shtml
The following link explains more about the Australian Bureau of Meteorology’s weather map and how it relates to Australia.
http://www.bom.gov.au/info/weathmap/weathmap.htm
Having an understanding of High and Low pressure systems enables the surf forecaster to identify the hot spots for swell generation, or in technical terms, the “fetch”. Once you have an understanding of High and Low pressure systems you need to learn how they affect the surf in the area. The following link provides a good explanation of the different elements you need to think about when interpreting and forecasting the height, period, wavelength and direction of swells.
http://www.goldcoastwx.com/swellfcst/fcst.html
Analysis and forecast charts are developed by scientists with the workable knowledge of algorithms and access to various sources of weather related data. Our knowledge is based on experience with Gold Coast surf and swells and a combined general understanding of reading and interpreting weather analysis and prognostic forecast charts.
Predicting and forecasting swell is not easy to do accurately all the time but a basic understanding of reading weather maps and following the local swells can make anyone a reasonable surf forecaster.
The weather maps surf forecasters are mainly interested in are the mean sea level synoptic analysis and prognostic forecast charts. Thanks to various organizations around the world we also have the added benefit of access to model generated swell forecasts, which have proved to be reasonably reliable and are becoming an integral element of all surf forecasters tools.
Analysis charts represent the real state of conditions using currently recorded weather data. Prognostic or forecast charts represent the future state of conditions formulated from predictions based on the analysis charts and other historic weather data.
Current Analysis Chart for Australia:
http://www.bom.gov.au/weather/national/charts/synoptic.shtml
Tomorrow Morning Quality Controlled Forecast Chart for Australia:
http://www.bom.gov.au/weather/national/charts/24hour_man.shtml
Tomorrow Night Computer Generated Forecast Chart for Australia:
http://www.bom.gov.au/weather/national/charts/24hour_cgen.shtml
Various factors influence the size, speed and direction of swell. The two main things surf forecasters analyse on the weather charts are the High and the Low pressure systems. High pressure systems turn anti-clockwise in the southern hemisphere and form upward air flows. Low pressure systems turn clockwise in the southern hemisphere and form downwards air flows. Low pressure systems are the real swell generating systems.
A great 1 page description by the Bureau of Meteorology about High and Low pressure systems for Australia can be found at the following link. The text and the animated graphics easily explain how they work and how they can work together.
High and Low pressure systems:
http://www.bom.gov.au/lam/Students_Teachers/pressure.shtml
The following link explains more about the Australian Bureau of Meteorology’s weather map and how it relates to Australia.
http://www.bom.gov.au/info/weathmap/weathmap.htm
Having an understanding of High and Low pressure systems enables the surf forecaster to identify the hot spots for swell generation, or in technical terms, the “fetch”. Once you have an understanding of High and Low pressure systems you need to learn how they affect the surf in the area. The following link provides a good explanation of the different elements you need to think about when interpreting and forecasting the height, period, wavelength and direction of swells.
http://www.goldcoastwx.com/swellfcst/fcst.html