On Tue, 4 Jan 2005 17:14:52 -0000, Stuart wrote in


What do the coloured lines reresent?

http://129.13.102.67/wz/pics/Rtavn1683.gif

Assuming you mean the green and blue lines - they indicate the thickness of
the 1000hPa to 500 hPa layer in decametres. The greater the value the
warmer the air is. Get some way below the 528 line and snow is
increasingly likely and at 510 is virtually certain.

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Mike 55.13°N 6.69°W Coleraine posted to uk.sci.weather 04/01/2005 17:22:59 UTC