On Mon, 20 Oct 2003 22:44:14 +0100, Will in
wrote:

Thanks David, superb links to IPV information.
The 400K T+72 from ECMWF looks really weird, not what I would expect to see. Are
there any dynamical climatologists looking in here who would care to comment on
the present situation ?

Will - not sure I am looking at same charts as you.....but if you clicked
on David's link to the ECMWF progs, they seem to be T+ from 00Z on 17th
March 2003.

--
Mike posted to uk.sci.weather 20/10/2003 22:15:05 UTC
Coleraine
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"Mike Tullett" wrote in message
...
On Mon, 20 Oct 2003 22:44:14 +0100, Will in
wrote:

Thanks David, superb links to IPV information.
The 400K T+72 from ECMWF looks really weird, not what I would expect to
see. Are
there any dynamical climatologists looking in here who would care to
comment on
the present situation ?

Will - not sure I am looking at same charts as you.....but if you clicked
on David's link to the ECMWF progs, they seem to be T+ from 00Z on 17th
March 2003.

--
Mike posted to uk.sci.weather 20/10/2003 22:15:05 UTC
Coleraine
Seeking information about the Internet and the way it works? - Subscribe
to
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That's what I thought but was too embarrassed to ask!
Mind you it does state in the right hand column

Current Date and Time a
Mon, 20 Oct 2003 22:21:15 UTC
(ECMWF (MM5) - Forecasts were initialized yesterday (today) at 12UT,
max. forecast time is +108h (+84h). Full FCs are normally ready at about
04UT.)

In uk.sci.weather on Mon, 20 Oct 2003 at 13:41:29, Philip Eden wrote :

In the last 10 years we have had major blocks in October on:
4-20 Oct 1994
17 Oct - 4 Nov 1997
30 Sept - 8 Oct 1998
11-22 Oct 1999
5-21 Oct 2002, which some of us seem to have forgotten
already.

Surely the issue is the duration of the blocking? It started at the
beginning of August!
--
Paul Hyett, Cheltenham

Email to pahyett[AT]activist[DOT]demon[DOT]co[DOT]uk

Perhaps we are in for a cold February like that of 1986. CET was -1.1^c

Shaun Pudwell.


"lawrence jenkins" wrote in message
...

"Mike Tullett" wrote in message
...
On Mon, 20 Oct 2003 22:44:14 +0100, Will in
wrote:

Thanks David, superb links to IPV information.
The 400K T+72 from ECMWF looks really weird, not what I would expect
to
see. Are
there any dynamical climatologists looking in here who would care to
comment on
the present situation ?

Will - not sure I am looking at same charts as you.....but if you
clicked
on David's link to the ECMWF progs, they seem to be T+ from 00Z on 17th
March 2003.

--
Mike posted to uk.sci.weather 20/10/2003 22:15:05 UTC
Coleraine
Seeking information about the Internet and the way it works? - Subscribe
to
news:uk.net.beginners

That's what I thought but was too embarrassed to ask!
Mind you it does state in the right hand column

Current Date and Time a
Mon, 20 Oct 2003 22:21:15 UTC
(ECMWF (MM5) - Forecasts were initialized yesterday (today) at 12UT,
max. forecast time is +108h (+84h). Full FCs are normally ready at about
04UT.)

The 400K T+72 from ECMWF looks really weird, not what I would expect to see. Are
there any dynamical climatologists looking in here who would care to comment on
the present situation ?

Will.
Unfortunately the forecasts are unavailable ATM but the analyses are good
ETA model tropopause forecasts to T+48 are at-
http://zephyr.meteo.mcgill.ca/gary/etatrop.html
for AVN to T+168 see-
http://www.atmos.albany.edu/student/mjd/maproom.html

http://met.psu.edu/tropical/tcgengifs/
has AVN PV products ,not polar projection.UKMO products seem curtailed here tho,

--Ive no expertise in these matters but it seems clear the arctic vortex is weak and warm
ATM,leading to negative indices of the annular mode,blocking etc.
regards,
david

"Vidcapper" wrote in message
...
In uk.sci.weather on Mon, 20 Oct 2003 at 13:41:29, Philip Eden wrote :

In the last 10 years we have had major blocks in October on:
4-20 Oct 1994
17 Oct - 4 Nov 1997
30 Sept - 8 Oct 1998
11-22 Oct 1999
5-21 Oct 2002, which some of us seem to have forgotten
already.

Surely the issue is the duration of the blocking? It started at the
beginning of August!
--
Well, actually, Paul, you just snipped the line where I gave an
example of a 90+ day sequence of blocked types - in
autumn 1993. And you also snipped the first line which
described the "issue" that I was raising. Duh.

pe

"Waghorn" wrote in message
...

The 400K T+72 from ECMWF looks really weird, not what I would expect to
see. Are
there any dynamical climatologists looking in here who would care to
comment on
the present situation ?

Will.
Unfortunately the forecasts are unavailable ATM but the analyses are good
ETA model tropopause forecasts to T+48 are at-
http://zephyr.meteo.mcgill.ca/gary/etatrop.html
for AVN to T+168 see-
http://www.atmos.albany.edu/student/mjd/maproom.html

http://met.psu.edu/tropical/tcgengifs/
has AVN PV products ,not polar projection.UKMO products seem curtailed
here tho,

--Ive no expertise in these matters but it seems clear the arctic vortex
is weak and warm
ATM,leading to negative indices of the annular mode,blocking etc.
regards,

As I think you infer, David, there is nothing all that unusual in a
multi-polar vortex. It is
very common to have 2 or 3 centres, and not uncommon to have more.
Climatologically
speaking, as you say, a weak multi-polar vortex is associated with a
low-index
circulation which in turn is associated with mid-latitude blocking. Just
like last October.
Just like October 1997. Just like October 1993. The mean monthly 500mbar
chart
for October 2002 had five identifiable centres inside the Arctic Circle. On
a
monthly/seasonal basis a favoured location is the Barent Sea, and of course
the
actual daily position will travel more widely around this mean location.

Philip Eden

"Philip Eden" philipATweatherHYPHENukDOTcom wrote in message
.. .

"Vidcapper" wrote in message
...
In uk.sci.weather on Mon, 20 Oct 2003 at 13:41:29, Philip Eden wrote :

In the last 10 years we have had major blocks in October on:
4-20 Oct 1994
17 Oct - 4 Nov 1997
30 Sept - 8 Oct 1998
11-22 Oct 1999
5-21 Oct 2002, which some of us seem to have forgotten
already.

Surely the issue is the duration of the blocking? It started at the
beginning of August!
--
Well, actually, Paul, you just snipped the line where I gave an
example of a 90+ day sequence of blocked types - in
autumn 1993. And you also snipped the first line which
described the "issue" that I was raising. Duh.


But as I said, the lack of rainfall is unusual and is dissimilar to the
years mentioned.
Unfortunately, it is similar to 1947. :-(

Victor

As I think you infer, David, there is nothing all that unusual in a
multi-polar vortex...
He,He...
I deliberately refrained from making a comment on the climatology Philip as I knew you'd be lurking
;-).It would be interesting to study the climatology from the new reanalyses to see if anything
unusual might be detectable-probably somebody is doing that.But even then 40-50yrs is a short time
span.
AS for whether anything could be happening I'll remain on the fence...and admire the view.The recent
history of these things is that singular events are taken as harbingers of climate change with
little or no reason ,when examined in the proper perspective.
Of course that doesn't mean we are not about to be caught with our pants down...you see I'm very
even handed ,
;-),

--
regards,
david

"Waghorn" wrote in message
...
The recent
history of these things is that singular events are taken as harbingers of
climate change with
little or no reason ,when examined in the proper perspective.

This is what I'm most often quoted as saying ... and I'm happy to, because
it needs saying. And yet people think that it means I'm a climate change
sceptic. (When I'm not). I can't imagine why ....

Philip Eden