"Bogdan Iqbal" wrote in message
...
Good morning friends. Take a look at Kasim Awan's thoughts on this winter.
It holds a lot of promise for snowfall I am sure you will agree.
http://kasimsweatherwatcher.com/uk-winter-2014-15/
I wish Kasim all the very best in his endeavours.
It is very refreshing to see younger folk so enthusiastic about our topic.
There are a lot of old scrotes on here, some grumpy, some less so. But there
is also a lot of experience and many of us are professionals or retired
professionals. So expect some scepticism (hopefully constructive).
My take on LRFs is this. We will never be able to give what the public
wants, i.e. accurate daily forecasts out for a whole season. The atmosphere
is inherently chaotic and always will be. The solutions to the Navier Stokes
equations are not analytical and computational solutions will eventually
develop magnifying errors.
What we may well be able to do is predict the character of a season.
Essentially will it be blocked or zonal or a mixture and when. If it is
blocked where will the block be - that matters a lot. If it is zonal, how
zonal? Will the zonality be progressive or pseudo blocked. Where will the
jet be, north, over or south of UK. If one could get the above right then
the general weather type will follow. No good trying to predict daily or
even weekly detail.
I issue a forecast at the end of November on my website on the above lines.
Last winter I went for wet with a southerly latitude strong jet. I got the
wet correct!!! But over-played lowland snow and cold over Scotland. Upland
snow though in Scotland was indeed exceptional. Here is the forecast as
issued:
" As usual I have been looking at sea surface temperature anomalies, how
Russia and Canada have cooled relative to each other, location of jet
stream, local statistics and predictions from other centres to try to come
to a consensus view for the weather this coming winter. The Arctic appears
to have cooled faster than normal this autumn and now Arctic Canada is
cooling rapidly. This would tend to encourage a strong westerly flow. Sea
surface temperature anomalies provide an uncertain signal and nothing really
to latch onto. The polar front jet stream continues at a lower latitude than
normal after a few migrations north earlier in the year. I cannot see this
pattern changing and fully expect the mean position of the jet stream to
continue to be further south than normal at around 49N in the Atlantic.
Probably stronger this year though than last. Last winter we had a major
stratospheric warming leading to some very cold easterly spells. It is rare
for these to occur in successive years, so I expect fewer easterlies this
winter. Finally, there is a good correlation between cold and wet Novembers
and cold winters in the UK. This November certainly looks like being wet but
may not be particularly cold, so another mixed signal. Putting all of the
above together I have come up with a forecast given with LOW confidence as
follows.
Winter 2013/14 is going to be a winter of rapid changes and a "rough ride"
for many. Overall I expect it to be neither a cold one nor a mild one but
temperatures may end up below average. However, I am expecting a wet winter
with fewer frosty, dry and cold spells than last winter. But given the
southerly located jet stream, incursions of deep very cold air from the
north could give some transient exceptionally heavy snowfalls, especially in
northern areas where snowfall could be above average. Further south, and
especially on low ground, snowfall will be more marginal, but here, flooding
may become a major issue. So the headline summary is wet and changeable with
the threat of substantial snowfall at times in northern Britain. "
It's always good to look back and learn from mistakes.
I am looking forward immensely to see what Kasim comes up with next month.
Cheers,
Will
--
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------