morgy Posted June 12, 2009 Share Posted June 12, 2009 Hi I was looking at a pressure chart from the met office and i noticed little red dotted lines and i wondered what they were and what they ment. I know how to read a pressure chart although i am not a weather pro. My first thought is that they are upper surface winds or jet stream but i dont know!! Can any one clear this up for me http://www.metoffice.gov.uk/weather/uk/ ... ssure.html Thanks morgy Quote Link to comment Share on other sites More sharing options...
druffuk Posted June 12, 2009 Share Posted June 12, 2009 Does this help mate?? http://www.metoffice.gov.uk/weather/uk/ ... l#pressure To quote :: Thickness lines Pressure decreases with altitude, and thickness measures the difference in height between two standard pressure levels in the atmosphere. It is proportional to the mean temperature of this layer of air, so is a useful way of describing the temperature of an airmass. Weather charts commonly show contour lines of 1,000-500 hPa thickness, which represent the depth (in decametres, where 1 dam = 10 m) of the layer between the 1,000 hPa and 500 hPa pressure levels. Cold, polar air has low thickness, and values of 528 dam or less frequently bring snow to the UK. Conversely, warm, tropical air has high thickness, and values in excess of 564 dam across the UK often indicate a heatwave. Quote Link to comment Share on other sites More sharing options...
dantheman Posted June 12, 2009 Share Posted June 12, 2009 Morgy, you were right about being related to the jet stream, I won't elaborate however this PDF will help you understand a bit more.... http://www.weatherweb.net/WeatherSchool ... Stream.pdf Quote Link to comment Share on other sites More sharing options...
morgy Posted June 13, 2009 Author Share Posted June 13, 2009 Thanks guys Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.