Will Hand wrote:

"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
-------------------------------------
...... and we all enjoy reading them ;-) The problem I have with most
seasonal forecasts is that they are always half right as with yours! My
random guess will probably be half right for a whole season. If I say
this winter will be more snowy than last winter, generally a mild one
with about average rainfall but with some short colder spells I bet it
will be at least half right.
Last year the critical things were RECORD rainfall and not a SINGLE snow
flake in large areas of the Country. Nobody got that and I doubt any
ever will. But as you say they are still of great interest (or hope!)
and there is still a lot that can be learned about climate and the
weather from the rationale that attempts to predict. So roll on November
for this winter's one!
Dave