On Wednesday, 13 January 2016 09:39:02 UTC, wrote:
"xmetman" wrote in message
...
On Wednesday, 13 January 2016 04:46:22 UTC, Tudor Hughes wrote:
On Tuesday, 12 January 2016 16:47:45 UTC, N_Cook wrote:
On 12/01/2016 14:58, Richard Dixon wrote:
On Tuesday, 12 January 2016 14:52:42 UTC, N_Cook wrote:
... to discover its affect on the North Sea sea levels.
The particular path is from the Icelandic area coming south , close
to
north of Scotland but passing west of it, and west of Ireland before
going NW, west or southwest, ie not over the UK. Preferably in the
last
20 years.
Any ideas how to go about it, other than squandering bandwidth on
weterzentral.de

This might be a useful starting point.

http://data.giss.nasa.gov/stormtracks/

Richard


Many thanks for that, what a useful resource. I've not found an example
in a winter quarter of the years I've chosen so far , but that is
probably associated with my conjecture.

Local marine flooding approx 100 years ago , on dates
27 oct 1909
26 dec 1912
05 Nov 1916
27 nov 1924
were more extreme than in the following decades to the present.
Looking at reanalysis of the synoptics for those periods, the associated
lows were not that extreme, but they took a track that just does not
happen these days, let alone 4 in 15 years, from the north, west of
Ireland and then turning into the English channel. Plenty of lows go
into the English Channel but don't produce historically excessive sea
levels, 1703 and 1824 events were probably due to true huricanes.
My conjecture is , due to the longer transit time via the North Sea,
close passage west or Scotland induces a positive surge into the North
Sea, that passes through Dover and attenuated going west through the
English channel but sums to the normal sort of west to east surge in the
channel associated with a low going into the channel from the west, so a
double-whammy.
Once I have a date I can check the BODC UK tide gauge data for North Sea
residuals
Incidently storm Frank seems to have induced a negative surge in the
North Sea inverse-barometer effect (from its south to north passage west
of Scotland) producing an east to west attenuated surge approx -0.7m in
our channel area that exactly cancelled an otherwise expected +0.7m
west to east surge in the Solent area, caused by the same Frank passage
in the Atlantic, taking 2 paths around the UK but temporally coincident
in the Solent.

A complicating factor in all this is the natural resonance of the
North Sea which can be amplified by the wind if the timing is right, i.e.
the speed of movement of the Low. My actual knowledge of this effect is a
bit skimpy but it was implicated in the North Sea Floods of Jan 1953.

Tudor Hughes, Warlingham, Surrey.

I have 2.5°x2.5° gridded data and I was going to set myself a programming
task of tracking highs an lows (yes I am quite sad but you have to fill the
days). Finding the crude position of highs and lows wouldn't be the problem
but keeping track of the low/high would using 6 hourly charts would be
difficult to automate and require some human input I reckon.
=========

I did just that (on a finer grid) when I was at work Bruce as I needed to
relate heavy rain areas to low centre. I programmed it in FORTRAN but I warn
you it was horrendously complicated with lots of "if then else" statements.
Unfortunately the actual code is Crown copyright (like all MetO code) and I
cannot help you in that. But good luck if you try it and if you need advice
on algorithms I'm here to help. The process was iterative looking at large
areas first then zooming in and storing coordinates. Then repeat at delta
time incrementing a rectangle in delta lat/lon and doing again and finding
centres. Then a clever bit of checking if movement was "realistic". Then
repeating all again for another area. IIRC it was CPU intensive.

Will
--
" Some sects believe that the world was created 5000 years ago. Another sect
believes that it was created in 1910 "
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------

I've just remembered that your paper on that is online. I recall reading it a few years ago. IIRC there is a chart with averaged Blocked pressure-centres It was all new to me back then and I didn't have a clue what to do about any of it.

One thing about Crown Copyright is that they give permission for non profit educational stuff. But there are bullying arseholes in any profession especially when the *******s can cause problems at little risk to themselves.

A spoke in the year on a dark night with you cap pulled down over your head works wonders on people like that. See the lamp post thread for details.