On Nov 24, 3:05*pm, Tudor Hughes wrote:
On Nov 24, 1:53*pm, Richard Dixon wrote:

On Nov 24, 1:04*pm, Stephen Davenport wrote:

Highs and lows are only defined relative to surrounding pressure and
are a human construct. There are no absolutes. The notation in this
instance merely marks the point of highest pressure in that locale.
Plus, yes, enthusiastic labelling.

Stephen.

I would guess though that (at least in the N Hemisphere winter) that
lower central pressure "highs" are more likely further north over
Greenland/Iceland/Norway given the low mean surface pressure in this
region? ( e.g.http://badc.nerc.ac.uk/data/ecmwf-era/pics/mslp.gif)

Richard

* * * * * * * The High is not real anyway because MSL pressures over
the Greenland icecap are meaningless. *The place only has "mean sea
level" at the edges and the interior is far too high for any
extrapolation to sea level to be useful. *It's probably best to regard
Greenland as a discontinuity in the MSL pattern and to regard the
isobars as formalities which do not necessarily bear any relation to
the circulation at the land surface. *The same is true of Antarctica,
even more so because of the greater extent and altitude of the
continent.

Sorry I missed your post Tudor.

I have since found the Canadian equivalent to the MetO's North
Atlantic. It encompasses most of the Northern Hemisphere short of
Russia:
http://www.weatheroffice.gc.ca/analysis/index_e.html

I suspect the MetOffice has a chart just like that, their computer
modelling is (I have heard) better than most for a global run.

So it could be that such divvi punctuation is just over-run from
models that showed an Arctic High ridged down the Mid Atlantic. (aka
Greenland in this case.)

As it happened the suspected wasn't a large earthquake. IIRC it turned
into a tropical storm.