Today's model interpretation (6/08/09)
Here is a summary of the NWP output for noon (GMT) on Wednesday.
Issued 0549z, 6th September 2008
The models are split today. ECM shows a trough crossing the UK during the
latter half of next week, with rain for all. GFS instead shows a weak ridge
by the end of the week, followed by a prolonged col.
Analysis and evolution to T+120 via GFS
Low pressure covers England and Wales, with NE'lies elsewhere. The low moves
eastwards tomorrow, with northerlies and NNW'lies as a result. Monday sees
the low move over the North Sea, with a col over much of the UK. Southerlies
and SSE'lies cover the UK on Tuesday as a weak ridge moves over England.
The jetstream chart shows a ridge over England and Wales, with the jet
heading northwards over Scotland and Northern Ireland. Upstream there's a
trough, with a strong and zonal jet over the western Atlantic. There are
southerlies aloft at the 500hPa level, again with a trough to the west. MetO
shows a trough to the west too, while ECM has upper SW'lies instead. GEM
brings an upper col over the UK.
At the surface GFS shows southerlies for all with a deep low to the NW and a
trough to the west. MetO has a shallower low to the west, resulting in
SSE'lies. SSW'lies affect the UK with ECM, due to a low to the SW. GEM has
low pressure over northern Scotland, with light WSW'lies elsewhere.
Evolution to T+168
Day 6 with ECM brings a deep low to the west, leading to strong to gale
force SSE'lies and southerlies. The low fills on day 7, with lighter
WSW'lies for all.
A ridge covers the UK on day 6 with GFS, leading to light winds. The ridge
persists on day 7, although by then strong SW'lies affect NW Scotland from a
low to the NW.
Looking further afield
On day 8 with ECM the UK lies under a col. England and Wales remain under a
col on day 9, as a high to the north of Scandinavia blocks an approaching
low from the west. Southerlies start to affect Northern Ireland and
Scotland. On day 10 the high builds slightly towards the UK, with light
winds for all.
SW'lies cover Scotland and Northern Ireland on day 8 with GFS, while England
and Wales lie under a col. A col covers most areas on day 9 and on day 10
there's little change.
The ensembles continue show a warmer spell next week.