I've seen omega blocks before, but the MetO output tonight is rather odd...

http://217.160.75.104/pics/Rukm1441.gif

That looks like an upper omega block over the UK, I assume that'd keep the
cold over us for a while. However, just to the west looks for all the world
like a *surface* level omega block - two blocks, side by side...

I've not seen that before.

"Darren Prescott" wrote in message
...
I've seen omega blocks before, but the MetO output tonight is rather odd...

http://217.160.75.104/pics/Rukm1441.gif

That looks like an upper omega block over the UK, I assume that'd keep the
cold over us for a while. However, just to the west looks for all the world
like a *surface* level omega block - two blocks, side by side...

I've not seen that before.



Darren, I think the western limb is only temporary, a surge of low potential
vorticity (warm air) which will help to maintain the omega block in the UK
longitude. Incidentally ECMWF 12Z from www.ecmwf.int is consistent with its 00Z
predecessor maintaining the block more or less over the UK and then
retrogressing slightly at the new T+168 stage. If that trend is continued then
we could be facing a cyclonic northeasterly in the extended outlook which would
be fun! GFS consistent with UKMO. All going to plan so far.

Will.
--

" Ah yet another day to enjoy "
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Will Hand wrote:
"Darren Prescott" wrote in message
...
I've seen omega blocks before, but the MetO output tonight is rather odd...

http://217.160.75.104/pics/Rukm1441.gif

That looks like an upper omega block over the UK, I assume that'd keep the
cold over us for a while. However, just to the west looks for all the world
like a *surface* level omega block - two blocks, side by side...

I've not seen that before.



Darren, I think the western limb is only temporary, a surge of low potential
vorticity (warm air) which will help to maintain the omega block in the UK
longitude. Incidentally ECMWF 12Z from www.ecmwf.int is consistent with its 00Z
predecessor maintaining the block more or less over the UK and then
retrogressing slightly at the new T+168 stage. If that trend is continued then
we could be facing a cyclonic northeasterly in the extended outlook which would
be fun! GFS consistent with UKMO. All going to plan so far.

Will.
--

" Ah yet another day to enjoy "
-------------------------------------------------------------------------------
A COL BH site in East Dartmoor at Haytor, Devon 310m asl (1017 feet).

mailto:
www: http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm

DISCLAIMER - All views and opinions expressed by myself are personal
and do not necessarily represent those of my employer.
-------------------------------------------------------------------------------



Your crystal balls give out more information than mine ;-)

--
Keith (Southend)
http://www.southendweather.net

"Will Hand" wrote in message
...
Darren, I think the western limb is only temporary, a surge of low
potential
vorticity (warm air) which will help to maintain the omega block in the UK
longitude. I
Thanks, Will - I'm still getting to grips with all this upper-air stuff,
having belatedly realised it's quite important regarding our weather!

ECMWF 12Z from www.ecmwf.int is consistent with its 00Z
predecessor maintaining the block more or less over the UK and then
retrogressing slightly at the new T+168 stage. If that trend is continued
then
we could be facing a cyclonic northeasterly in the extended outlook which
would
be fun! GFS consistent with UKMO. All going to plan so far.
Going by today's performance, GFS isn't even consistent with itself - a
stranded fish would do less flip-flopping! Over the past day the models seem
to have backed away from that Siberian easterly blast shown by the JMA, ECM
and GFS at various stages, but the latest scenario of high pressure parked
near the UK would still be pretty cold.

The ECM ensembles tonight point to a prolonged cold spell just to our east,
it seems that idea of an omega block near the UK is well supported:

http://www.ecmwf.int/products/d/samp...rope/page.html

Darren Prescott wrote:

I'm playing some ABBA tonight, to get into that Scandinavian atmosphere :-)


--
Keith (Southend)
http://www.southendweather.net