Winter Storms

[Cookie]

I've watched many a program about Storms in the winter in the uk. One common element that keeps coming up is that low pressures coming off the Atlantic are going to get bigger and stronger. that as the climate changes these storms are going to get worse.

I have a very basic knowledge of climate change. are the winter storms getting worse? is their any proof to say that things are going to get much worse, that these systems are going to become more frequent.

If things are going to get worse will it happen in my lifetime? is their any proof that it hasn't happened in the past.

whats the worst case serinco more storms for the uk like 2005 ( Scotland) and 1987 ( england)

or is it just a lot of hype?

** sorry for a lot questions really interested in finding out more information **

[Gray-Wolf]

I've watched many a program about Storms in the winter in the UK. One common element that keeps coming up is that low pressures coming off the Atlantic are going to get bigger and stronger. that as the climate changes these storms are going to get worse.

I have a very basic knowledge of climate change. are the winter storms getting worse? is their any proof to say that things are going to get much worse, that these systems are going to become more frequent.

If things are going to get worse will it happen in my lifetime? is their any proof that it hasn't happened in the past.

whats the worst case serinco more storms for the UK like 2005 ( Scotland) and 1987 ( england)

or is it just a lot of hype?

** sorry for a lot questions really interested in finding out more information **

Hi Cookie!

I don't think we're talking purely 'winter storms' but a potential for all storms to have a little more 'oomph'.

With more energy available in the system (in the form of heat) then we can expect more vigorous storm systems to form. In as far as 'winter storms' are concerned I would imagine that tropical airs pushing further north will connect with polar airs leading to a good deal of potential difference between both air masses (temp,humidity) and the inevitable 'vigorous exchanges' will result (as we see in the mid-west each spring/early summer as warm from the GOM meets cold/dry from the arctic) as both masses move towards parity.

As warmer air masses displace polar air we get anomalous temps within the arctic but also short lived 'cold plunges' as the displaced airs flow south. The recent heavy dumpings in Japan,Eastern Europe,Greece and the U.S. show how big an impact such a short term event can have. Here in the U.K. we are not immune from such events and I still avidly wait for a proper 2 footer as high arctic air masses are displaced in our direction by the tropical 'warm plumes' on the other side of the arctic (well.....I can hope can't I???).

Recent research has proven that tropical cyclones are also becoming stronger. They may find it more difficult to find the 'perfect environment' to grow as upper level shear increases but when they do (from measurements taken over the past 15yrs) they seem to be increasing in both size and ferocity.

I'm sure the more competent 'weather heads' out there will have more info but this starts the ball rolling eh?

[eddie]

I was under the impression that, in the long term, winter storms would become weaker due to a reduced thermal gradient caused by the arctic warming faster than everywhere else.

[Gray-Wolf]

I was under the impression that, in the long term, winter storms would become weaker due to a reduced thermal gradient caused by the arctic warming faster than everywhere else.

and in the short/medium term as nature does her forced 'balancing act'????

[eddie]

and in the short/medium term as nature does her forced 'balancing act'????

Hard to say really. There seems to be anecdotal evidence that it was very stormy in the transition period into the little ice age but that was a cooling event and would have increased the thermal gradient as the arctic cooled.

I think it's fair to say that you might expect some unusual weather when the climate changes to a new state but that might equally mean a 10 year drought rather than more winter storms.

Cookie, you may find this chart interesting....

from a paper that looks at 300 years of storms in Dublin

A three-century storm climatology for Dublin 1715-2000

/edit

Did a bit more digging and although winter storms might not increase in frequency there are likely to be more summer-autumn storms (extra-tropical hurricanes).

[Cookie]

thanks guys for you're responses

and thanks for the chart eddie very interesting.

[Cookie]

anyone got anymore info to add?

[Gray-Wolf]

Hi Cookie!

Yup, dug out this 50y study by Nasa......

http://www.terradaily.com/reports/NASA_Stu...limate_999.html

[Gray-Wolf]

Something I gleaned from one of the other threads on the board (god only knows where) The Omagh observatory records for storms show no trend up wards but they do seem to note a trend northwards for storm tracks.

Maybe the METO hold records that point to a similar trend.

If so what would a shift north mean for our experience of 'winter storms'. If the cores move ever far north then we might expect longer periods of mild SW draws and longer periods in between warm/cold fronts.

I would also think that,for those further south, it would mean a lessening in mean windspeeds as the depression drifts by to the north and less 'active' fronts as they pass over.

Any thoughts?

[cheeky_monkey]

im no expert by any means..i would expect the southern half of the uk to become drier and milder..with winters equal to those of 74-75, 75-76 & 89-90 but any rain to be light and patchy..or heavy and intense as fronts meander and are slow to clear..to be interspersed by long drier spells of bartlett high pressure influenced weather?

[Snowyowl9]

It`s reversing, in the summer the jet has been way south of where it should be and we`re getting more wind/gales even in summertime and much/much wetter.

Even the last 2 winters have seen an increase in storms further south especially 2006/07 worst storm since 1990 which was the stormiest period 6 years I`ve ever seen(1988 to 1993 not forgetting october 1987 hurricane which didn`t come this far north thankfully.

[Gray-Wolf]

It`s reversing, in the summer the jet has been way south of where it should be and we`re getting more wind/gales even in summertime and much/much wetter.

Even the last 2 winters have seen an increase in storms further south especially 2006/07 worst storm since 1990 which was the stormiest period 6 years I`ve ever seen(1988 to 1993 not forgetting October 1987 hurricane which didn`t come this far north thankfully.

I have spent a day struggling to find any evidence of this and the 'closest' I've been able to find is that a sinuous 'loop' of the jet has blighted our summers for 2 years running now. I would not see one portion of the polar jet as indicative of a 'southerly migration' of the Jet. I believe that the 'mean' position of the jet, taken over long periods, is what is highlighted by the NASA paper and not individual events.

If you could allow us to view the evidence you hold I am more than willing to update my current thinking on the matter

[Snowyowl9]

I have spent a day struggling to find any evidence of this and the 'closest' I've been able to find is that a sinuous 'loop' of the jet has blighted our summers for 2 years running now. I would not see one portion of the polar jet as indicative of a 'southerly migration' of the Jet. I believe that the 'mean' position of the jet, taken over long periods, is what is highlighted by the NASA paper and not individual events.

If you could allow us to view the evidence you hold I am more than willing to update my current thinking on the matter

Lets see what the winter brings first, then if next summer continues on another repeat of the last 2 very poor summers, I hope not.

[Cookie]

Hi Cookie!

Yup, dug out this 50y study by Nasa......

http://www.terradaily.com/reports/NASA_Stu...limate_999.html

thanks everyone and gray wolf, forgot about this thread

[Pingo]

There is of course no evidence for this. Computer models are unfortunately missing about 97% of climate variability. Until we can explain the weather, we can't explain why climate changes.

If there is a theory that winter storms have worsened, then all that is needed is an empirical study assessing wind speed, depth of pressure, etc - you know, the usual things people do when doing a proper statistical study; rather than the way climate scientists go about things with a pre-determined conclusion in mind.

I'd happily take part.

[Gray-Wolf]

There is of course no evidence for this. Computer models are unfortunately missing about 97% of climate variability. Until we can explain the weather, we can't explain why climate changes.

If there is a theory that winter storms have worsened, then all that is needed is an empirical study assessing wind speed, depth of pressure, etc - you know, the usual things people do when doing a proper statistical study; rather than the way climate scientists go about things with a pre-determined conclusion in mind.

I'd happily take part.

Isn't that what we've (the scientific community) been doing?

Isn't that why we know storms are tracking North and their intensity increasing?

Aren't we logging more extreme rainfall events (how many hundred year events can you have in one decade esp. when folk are predicting just that type of increase as a result of AGW)?

[paul tall]

Gray wolf, make sure these hundred year events actually are hundred year events before saying how many we can have in a decade.

[7andY]

AIUI, you could have ten Hundred Year events in a decade. You should not get another for a thousand years, just to set the averages straight, but even that's not guaranteed - it depends how many you had in the previous thousand years... :blush:

Cheers, 7&Y