"Hugh Newbury" wrote in message
...
On 27/07/10 18:12, Martin Rowley wrote:
"Len Wood" wrote ...
On Jul 27, 4:08 pm, Hugh Newbury wrote:
I know the diagrams of fronts in the books, showing the sloping
boundary
between the warm and cold air, etc. But what do they look like
when
they
pass over my garden (a) as seen from the ground, and (b) on the
data
from the AWS?
... as Len has hinted, you've asked a question to which entire
chapters of elementary text books are devoted - and still you
wouldn't
get the definitive answer!
If you look at this link first (US based, but a good 'primer', and
based on the 'Norwegian' frontal theory which of course has
developed
considerably over the past 100 years), then you'll get an idea of
the
'ideal' .... then it's a case of looking at each 'real' example in
turn and working out how they behave by comparing your data (and
observation) with the ideal ....
http://ww2010.atmos.uiuc.edu/(Gh)/gu...rnts/home.rxml
then click on each front etc. .... it's called 'cardboard'
meteorology
(from the cut-out models that used to be used in MET training
schools
to demonstrate fronts etc.), but you've got to start somewhere :-)
Martin.
Len, Martin, thanks for that. I suspected as much, but there's
always a
chance that there's a cunning way of looking at these mysterious
things.
Hugh
--
Hugh Newbury
www.evershot-weather.org
.... whatever you do, don't be put off! These 'ideal' cases are a good
way to start - then you can pick up on some of the variations later.
For example, this evening's cold front should show strong elements of
the diagrammatic 'ideal', with a wind veer, drop in dew point, and
change in cloud character as the colder, post-frontal air kicks in -
possibly complication (aren't there always), is that Exeter have drawn
*two* cold fronts on the 12Z ASXX - the rearward one marks the
'proper' polar maritime air mass, though again, at this time of year
it's heavily modified. There probably won't be much (if any) rain on
it though - a short burst of drizzle is all I'm expecting here.
Martin.
--
Martin Rowley
West Moors, East Dorset (UK): 17m (56ft) amsl
Lat: 50.82N Long: 01.88W
NGR: SU 082 023