Calculating wind speed using a pressure chart

[whitingjr]

Just a quick question on reading the wind speed from pressure charts. I can't recall which of the two methods should be used.

1) Measure the distance between the isobars with a ruler perpendicular to the isobars.

2) Measure the distance between the isobars with the ruler intersecting the centre of the weather system.

Which of the two methods should I use ?

Thanks,
Jeremy

Note, the cetre of the weather system is indicated by a cross on the following chart.
http://www.wetterzentrale.de/pics/brack0.gif

 

[burgundyben]

as per point 1, I think....




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[ccscott49]

There should be a little scale, on the pressure chart, which shows you the distances/wind speeds and method 1, I think aswell!!

 

[rickwat]

Yes I think as near perpendicular as possible and use the scale in top left corner of the met chart you quote using your own latitude. However I think it is important to bear in mind your position between the isobars and estimate the spacing with you in the middle so if the next space is much narrower you increase your assessment of speed and vice versa. Obviously you can't be super accurate but with the charts you quote for a particular place on a shortish forecast you can probably do better than other sources.

 

[halcyon]

There used to be three scale, Beaufort force, Warm front speed (knots), Cold front speed (knots), measure at right angles. This allowed you to measure wind speed, front speed and direction.

Most down load charts Iv'e seen do not have speed on, the Atlantic one I pick up have wind speed but not front speeds.

Who knows to downloadable charts with the three graphs on ?


Brian

 

[whitingjr]

Many thanks, the charts I reference are here by the way:

http://www.franksingleton.clara.net/essential_sites.html

Jeremy