Re: Some further thoughts on the Winter ahead

James Brown wrote:

I know a couple of our 'proper' resident meteorologists have, along with
the Met Office, mulled over the prospects for the coming Winter, and I
appreciate their prognostications! but a few more weeks have passed and
I wonder if there are any more portents or indicators of what might lie
ahead?

For myself as a simple amateur, all I can call upon is a hazy
recollection of quite a few decades of Winters now ;-) and with the help
of the Internet see something of an overview of prevailing patterns and
conditions.

Ignore the following as an irrelevant ramble by all means, but these are
my current conclusions.....

1. For many weeks in October there appeared to be a conveyor belt of
westerlies from the Atlantic right across Russia and on into the
Pacific. Eventually the jetstream did move enough to the south to allow
the NE of Russia to cool down and indeed is now showing familiar low
temperatures. However, the penetration of the westerlies continues
courtesy of deep low pressure areas in the NE Atlantic. This is leaving
most of Eastern Europe without settled cold conditions. On the other
hand, that same setup seemed to favour slightly more rapid ice
development in some parts of the polar regions, away from NW Russia. I
use the following URLs as a helpful overview for this analysis:

http://www.uni-koeln.de/math-nat-fak/geomet/meteo/winfos/arcisoTTPPWW.gif
and
http://iup.physik.uni-bremen.de:8084/amsr/arctic_AMSRE_nic.png

2. I'm not a great fan of using Atlantic SST's as a perfect guide to
positioning of low pressure areas but can't help but note from:

http://www.osdpd.noaa.gov/PSB/EPS/SST/data/anomnight.11.10.2008.gif

two things.
1. The warmer waters that are extensive in the western Atlantic, and
2. The continued apparent percolation of colder water from Iceland down
into the North Sea. I use:

http://91.121.93.17/pics/Reursst.gif
and
http://www.wetterzentrale.de/pics/brack5.html

to monitor these matters.

3. I was in the Warwick area when the snow came down at the end of
October - beautiful to see Kenilworth castle completely snow covered
against a blue sky, a bit unusual I felt for the time of the year, but
like others I regard it mostly as a singularity, but with a small
suspicion that it was an indicator of the potential potency of northerly
outbreaks.

So, getting it all together:

Although these are still very early days, I don't believe the signs are
there for the build-up of severe cold in Europe, particularly towards
the east. I see this as a more permanent feature of Winters rather than
a one off. Too much mobility, too little snow cover, too little ice to
the north east, etc. Without that when easterly winds occur they will
lack the bite that comes when the air is flowing off large snow fields.
Undoubtedly Omega blocks will form and we'll get sustained anticyclones,
but they will IMHO be of the cool and cloudy variety.

OTOH, I think there could be some interesting northerly outbreaks,
perhaps prolonged at times, and always with the possibility of small
lows breaking across more southern regions. Deep lows produce more
dramatic conditions pulling very cold air down in one place, but pushing
much milder air further up in others. Thus strong northerlies in the
North Sea area would produce strong southerlies over Scandanavia - and
it is this tighter barocline - if that is the term - which in many
recent years I believe personally, and I underline the 'personally' has
prevented the kind of Winters that when I were a lad, were more
prevalent

Overall, I would go for a slightly colder than average Winter, but with
the cold coming from the north rather than the east.

There you go folks. I'll try and remember to archive the prediction for
analysis next Spring!


The SST anomalies suggest a similar scenario. A warm anomaly near 40N 40W
would lead to a NW'ly winter with a high-pressure anomaly in mid-Atlantic
and low over Scandinavia. The current position of the anomaly seems a
little east of this position and suggests we may get more of mild air
rounding the top of the high than cold plunges and so I'll go for a mild
winter again. Might well be drier than normal in the south and south-west.

This forecast assumes the anomaly persists for the winter. A similar pattern
at the end of October 2000 had dissipated by the end of November.

--
Graham P Davis, Bracknell, Berks., UK. E-mail: newsman not newsboy

.