I notice on the link below there is a reading of 1000mb layer thickness. I assume this is generated with the data from the
Vantage Pro using javascript. The question is, how is it done and is it accurate. They are apparently using virtual temps.
If anyone knows I'll have a go at displaying the reading on our college weather site
http://users.adelphia.net/~gary.oldham/ashburnwx.html

Regards,

Rob
Chester, UK
http://www.west-cheshire.ac.uk/weather/

Look in the source. As to the accuracy of the algorithms, maybe
someone else with the right background can comment.

JGD
www.weatherstations.co.uk

On Wed, 24 Nov 2004 19:35:02 -0000, "Rob Bale"
wrote:

I notice on the link below there is a reading of 1000mb layer thickness. I assume this is generated with the data from the
Vantage Pro using javascript. The question is, how is it done and is it accurate. They are apparently using virtual temps.
If anyone knows I'll have a go at displaying the reading on our college weather site
http://users.adelphia.net/~gary.oldham/ashburnwx.html

Regards,

Rob
Chester, UK
http://www.west-cheshire.ac.uk/weather/

What that site is displaying is the 500 to 1000 mbar layer thickness. To
calculate this, you need to know the mean temperature of the atmosphere
between the two levels, and this can only be reliably done by flying a radio
sonde instrument. However, next best is to use the 500 mbar height obtained
from a current or forecast chart. The 1000 mbar height can be calculated
approximately from a knowledge of the station altitude above MSL, the
station level pressure, and an estimate of the temperature between station
level and sea level. In the UK this is taken as being isothermal at the
station level temperature. It is not possible to calculate the 500/1000
thickness from surface readings alone.

--
Bernard Burton
Wokingham, Berkshire, UK.

Satellite images at:
www.btinternet.com/~wokingham.weather/wwp.html
"Rob Bale" wrote in message
...
I notice on the link below there is a reading of 1000mb layer thickness.
I assume this is generated with the data from the
Vantage Pro using javascript. The question is, how is it done and is it
accurate. They are apparently using virtual temps.
If anyone knows I'll have a go at displaying the reading on our college
weather site
http://users.adelphia.net/~gary.oldham/ashburnwx.html

Regards,

Rob
Chester, UK
http://www.west-cheshire.ac.uk/weather/