On Saturday, 4 January 2014 22:12:35 UTC, John Hall wrote:
In article ,
John Hall writes:
In article ,
"Keith (Southend)G" writes:
And then ones wonders what the SSW stiuation was in years like
1947 and 1963, especially when 1947 didn't get going until later in
January, but here I go again marching up that hill LOL.
Sadly I don't think the measurements would be available for 1947, and
probably not for 1963 either. The NOAA record only goes back as far as
March 1979.
You can access their archive he
http://www.cpc.ncep.noaa.gov/product...e/temperature/
Here's the 10mb graph for 1985 and 1986:
http://www.cpc.ncep.noaa.gov/product...e/temperature/
archive/10mb9065_1986.gif
The cold Jan/Feb of 1985 seem to have been preceded by a major SSW in
Dec 1984. The very cold Feb 1986 was preceded by a rather "jerky" SSW in
Dec 1985 and Jan 1986. Of course that doesn't prove that they were cause
and effect.
The very mild winter of 1988-9 had a major SSW at the end of December.
There was a long period in the second half of January and first half of
February when pressure was very high - especially in the south of the UK
- but the centre of the High was positioned just to the south or east of
southern England pretty much throughout, giving winds between west and
south across the country.
It's beginning to look as if most winters have a significant SSW at some
point, and that these may be linked to a blocking anticyclone appearing
a few weeks later, but that the result for our weather will depend on
just where that anticyclone is centred, about which the fact of the SSW
may not tell you anything.
ETA: I've now looked at some 50mb graphs. Interestingly the Dec 88 SSW
didn't reach down as far as 50mb. That in Dec 84 did, and I wondered if
that might be an indicator as to where the High was likely to be
positioned. But sadly the SSW in Dec 85/Jan 86 isn't very evident at
50mb, so its SSW is more similar to the one in the 88-9 winter than the
one in the 1984-5 winter.
--
John Hall "He crams with cans of poisoned meat
The subjects of the King,
And when they die by thousands G.K.Chesterton:
Why, he laughs like anything." from "Song Against Grocers"
Thanks John for looking at some of the past SSW situations. What does seem certain, is a change in weather type can be expected when one occurs and I'm sure some 'others' may have a better idea at some of the differences in SSW set-ups and a better idea of the outcome on the ground. But we have come a long way in meteorology over the years to a point where we monitor a previously unknown feature and now look in anticipation at what effect it may have in the coming weeks. All good stuff.
Keith (Southend)
http://www.southendweather.net
"Weather Home & Abroad"
twitter: @LawnscienceEssx