On 13 Mar, 05:35, "Darren Prescott" wrote:
Here is a summary of the NWP output for noon on Wednesday.
Issued 0534, 13th March 2010
A NW/SE split will be evident for much of the week, with high pressure close
to the SE keeping things largely dry there and with a greater risk of rain
the further north and west you are. By the weekend a change in type could be
on the cards as the jet moves south again, thus bringing the rain risk
further south too.
I took the liberty of pasting this and the one from
http://groups.google.co.uk/group/uk....7d49b5b6847e2#
into a spread sheet set out as 2 columns for comparison.
The time period covered is for a particularly interesting period as it
ushers in the next spell on Monday (the one covered in the older
posting.)
And that spell is due to be a thundery one. What is interesting is
that it shold be the first weather forecast free of upsets caused by
the problems which eventually developed into the massive earthquake in
Chile and its repercussions since.
(Hopefully.)
It is a pity that one may not reproduce the twin column as pasting one
under the other loses something of the effect. (On Google at least -I
imagine the format is much the same on other readers/sites)
Analysis and evolution to T+120 via GFS
NW'lies cover the UK with a high to the west. Tomorrow there are WNW'lies as
the high drifts slowly SE'wards, followed by westerlies on Monday. Tuesday
sees a ridge over the UK with westerlies for all.
T+120 synopsishttp://91.121.93.17/pics/Rtavn12015.png/http://91.121.93.17/pics/Rtavn1201.pnghttp://91.121.93.17/pics/Rukm1201.gifhttp://91.121.93.17/pics/Recm1201.gif/http://www.meteociel.fr/modeles/nogapse_cartes.php
Fore reference to those hoping to see what can be seen at the time of
posting, the links point to charts that are updates regularly. The
same is true of any national government database such as the NEIC
recent quakes lists. So if you want 'em, grab em fast.
Here is Darren's summary of the above:
The jetstream chart shows a weak westerly flow over the UK, with the jet
resetting to a more southerly track upstream. ECM has SW'lies aloft due to a
shortwave trough over Ireland, while MetO has upper westerlies and a zonal
flow over western Europe. GEM brings upper SW'lies with a ridge to the east
and JMA has upper SW'lies too.
At the surface, GFS brings southerlies and a weak trough over Scotland. ECM
also brings southerlies, while MetO has SW'lies and also a weak trough for
Scotland. GEM has southerlies and JMA has SSW'lies, both with a trough to
the north.
Evolution to T+168
ECM shows WSW'lies on day 6 as a weak ridge moves eastwards, followed by
SSW'lies on day 7 as another trough crosses Scotland.
GFS brings southerlies on day 6 as a low deepens to the SW. On day 7 the low
moves northwards and a trough extends towards the UK, with easterlies and
ESE'lies as a result.
Looking further afield
ECM shows a low over England on day 8 with NE'lies to the north. NE'lies
affect most areas on day 9 due to a high over Scotland and on day 10 the
high extends over most of the UK.
GFS has low pressure over the Scottish borders on day 8, leading to SW'lies
ot the south and NE'lies to the north. A col covers the UK on day 9 and on
day 10 southerlies pick up ahead of a low to the west.
Ensemble analysis
(http://91.121.94.83/modeles/gens/gra...ext=1&y=141&ru...)
The GEFS shows above average means later next week, albeit mainly due to
warm nights.
ECM ensembleshttp://www.meteogroup.co.uk/meteo/eps/ensemble-tt6-london.gif
The ECM ensembles show temperatures not far from average for the forseeable
future.
For residents of the USA and Canada, flaccid systems do not appear to
affect the UK the way that they do in the USA*. If the NAO remains as
negative as it has for the last ages and ages?? the likelihood is for
more tornadoes and increased seismic activity ove the chain of islands
running from Alaska to Japan. (Including the Russian peninsula.)
As not quite stated in an earlier post on s.g.e. the reason for the
increased background in for example the Andreanoff Islands is that the
cause is tied in with the cause of tornadoes generally and that the
acoustics involved in their cases are that 80 degree harmonic. (or it
might be a 90 degree if the differences to the ... never mind.. some
of the sheep on here have enough diffiiulty...)
Any, the point is: We don't know if the spell is going to be a flaccid
one yet. Precipitations will be much the same in either case here.
(*Obviously there is a tendency to flash flood with a strongly
positive NAO.)
Whatever develops it should be one to watch. A marker for future
events of this nature.