"Col" wrote in message
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"Will Hand" wrote in message
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"Col" wrote in message
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"Rob Brooks" wrote in message
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At long last A High of significance - had a quick look back at my
pressure readings this year and today has seen the highest pressure in
Leeds since 17 March. It's now 1038mb and still rising.

Is this really surprising, though?
In terms of pressure readings isn't a winter anticyclone likely to be
more
'intense' than a summer one?

dynamics lesson
Why? And don't say because the air is colder as that would not be the
right answer, this high has 552DAM air entrained. The reason is all in
the dynamics - this high developed at the left entrance of a confluent
relaxing upper trough and right exit of an Atlantic jet both regions of
upper level convergence due to ageostrophic wind components. Also we had
a deep low with a lot of wind and kinetic energy which has been converted
to potential energy helping to raise pressure substantially. This is a
warm and intense high.
/dynamics lesson

Will, I don't understand any of that
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Sorry Col, I forgot you hadn't done an advanced forecasting course or the
Met. degree at Reading :-)

To put it more simply, two upper air flow patterns occurred close together
where the wind flows were such that they produced a coming together of air
high up in the atmosphere at around 30000 feet. This air was forced to come
down as the tropopause higher up was acting as a lid. This downward motion
transported masses of air into one place and pressure began to rise at the
surface. Meanwhile at the same time a very deep low began to fill up and the
kinetic energy of the fast moving air was converting to potential energy
(energy is never lost) reinforcing the effect of the coming together of the
air flows.

Is that better?

Will
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