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This posting expresses the personal view and opinions of the author.
Something which everyone on this planet should be able to do.
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Hi Pete, such a low is usually termed "an anchoring low" in professional
circles. It has the effect you describe and comes about when the upper longwave
pattern is stable.

The present longwave pattern is not stable as the wavelength is still increasing
as the wave amplitude increases due to cold advection sending the jet
southwards, thus one can expect a lowering of temperature levels during next
week and then as the wavelength increases a mid-atlantic ridge can form and
*may* initiate an Iceland block giving a long cold spell *or* it may topple SE
giving a short 2 day cold snap, the answer is unknown and lies in detail which
is still in the making.

Shoot that mother of a ridge up northwards baby :-)

Cheers,

Will.
--

" A cup is most useful when empty "
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Pete B wrote in message ...
"Gavin Staples" wrote in message
...

snipped

Sorry chaps, for those wanting some proper winter weather. If you take a
look at this excellent forecast and description below of the next few days
from Metcheck, you can see that we are in for a jolly good zonal period
reminiscent of the mid 1970s. This also ties in nicely with Darren
Prescott's forecast today.
I reckon if we see snow lying here in Cambridge this month at all,
then I'll see Elvis on Mars.



Stack 'em up Baby!
Added [Wednesday January 07 2004 : 2:42:49 PM]

The UK is set for a rough old time over the next few days as a mature
depression settles over Iceland.

The system is quite unique as it is one of the first lows for a long time
to
develop closed circulation all the way up to the jet stream.
In short, this means it's a mother of a depression and is likely to stick
around for quite a while as it wobbles and tilts to the Northwest.
Usually depressions have closed features at the surface, but are "steered"
by the jet stream which blows from West to East at 250mb.
This new Icelandic Low has the ability to feed on itself as it's spinning
like a top all the way up to 35,000 ft
So what does this mean for us? Well, the low will spawn off vicious
secondary lows as the jet stream is forced to duck-dive under the
Icelandic
low and heads in at 250mph from the Southwest. Thursday evening could see
a
nasty low head into Southern areas with another for Northern areas on
Sunday.

Expect timings to change a little, all models have real problems with
upper
air lows due to the lack of data at these levels but one thing is for
certain.... batten down those hatches!


Might such a system be referred to as a "Blocking Low", the low pressure
equivalent of its high pressure counterpart?. Steers everything around
itself while it hangs around in almost the same location with little or no
real change for days or weeks on end bringing day after day, week after week
of the same broad weather type to regions affected by it. Similar overall
circulation type to, say, Jan/Feb 1990.

Does such a description of a 'Blocking Low' officially exist as a recognised
atmospheric phenomenon to the Professional Meteorologist?

--
Pete

Please take my dog out twice to e-mail

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The views expressed above are entirely those of the writer and
do not represent the views, policy or understanding of any
other person or official body.
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Source Metcheck.

My Comment:
See what I mean.
--

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