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Post by raveninghorde on Dec 31, 2009 12:18:07 GMT
From theweatheroutlook.com//quote Confidence on the details is low, but if the general pattern is correct we'd not be surprised to some -20C recorded in the UK before middle January. There is a reasonable chance that some minimum day temperature records will be broken. So after a cold December with widespread snow it looks as though January will start off in a similar vein. Our winter forecast suggested this would be the second consecutive UK winter with colder than average temperatures, and we are now increasingly confident that this will be correct. We've heard some people suggest the chances of a cold winter in the UK are now as low as one in thirty due to climate change. If this is the case it would suggest a one in nine hundred chance of having two cold winters in succession! /end quote
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Post by hunter on Dec 31, 2009 13:48:09 GMT
Steve demonstrates the classic non-falsifiable aspect of AGW rather well.
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Post by aj1983 on Dec 31, 2009 14:46:37 GMT
Wow, this guy is annoying. What's in a name. Anyway, I'm getting really frustrated by the fact that there are several "forecasters" predicting a cold winter EVERY YEAR. Of course ONE year you will hit the jackpot if you do that. However, their arrogant attitude if they do so is very annoying, considering that they have forecasted one out of 5 or even one out of 10 correct, while statistically they should have gotten an even better score. (e.g. Piers Corbyn in the UK (cold winters since 2005), Piet Paulusma in the Netherlands (forecasts cold winters almost as long as I can remember, for at least a decade I think), and I'm not sure about Bastardi. Even Meteo Consult (a private meteo company here) has been saying SINCE 2004!!! that "this year we will have a cold winter". This hasn't verified until now, but this year again they are presenting their forecast as if it is one with great accuracy and skill. (Yeah, one correct forecast out of 6, if it is correct because it still has to verify!) Great scores! Currently the NOA index is strongly negative. It has been a long time ago since we had that. (1996, which was a cold winter year for Europe, www.knmi.nl/cms/viewimage.jsp?number=27923) As long as that doesn't change we (West/Central Europe) will have colder than average weather, because the usual westerlies will reverse to easterlies (or just much more variations due to blocking patterns). Is this surprising? No. A trend to colder weather? For this current winter, maybe. Probably the summer will be warmer (as Bastardi states correctly), as long as the NAO remains negative (no one knows...). It would be interesting to see if there is a link between solar activity and NAO. I thought this has been researched before, and that no strong correlations could be found, but I'm not sure. My forecast: it will be colder than average most of this year, but warm spells will still be possible. The coming years we will have a few colder and many warmer winters again. Useful, right? Forecasting monthly weather is something completely different than decadal or centennial climate. I'm also wondering why the UKMET gives so much attention to their seasonal forecasts, because they are clearly unreliable too. The the Dutch national weather service is much more honest/professional in stating that they don't do operational seasonal forecasts, because their experimental seasonal forecasts are too much unreliable to be used. (We are not under the influence of strong somewhat predictible oscillations like the ENSO)
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Post by aj1983 on Dec 31, 2009 14:49:00 GMT
From theweatheroutlook.com//quote Confidence on the details is low, but if the general pattern is correct we'd not be surprised to some -20C recorded in the UK before middle January. There is a reasonable chance that some minimum day temperature records will be broken. So after a cold December with widespread snow it looks as though January will start off in a similar vein. Our winter forecast suggested this would be the second consecutive UK winter with colder than average temperatures, and we are now increasingly confident that this will be correct. We've heard some people suggest the chances of a cold winter in the UK are now as low as one in thirty due to climate change. If this is the case it would suggest a one in nine hundred chance of having two cold winters in succession! /end quote What is their definition of a cold winter, and what is yours? Probably that explains the difference...
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Post by raveninghorde on Dec 31, 2009 16:26:04 GMT
What is their definition of a cold winter, and what is yours? Probably that explains the difference... I guess their idea of a cold winter is one that is colder than average. Mine is when the central heating has to be on 24/7 for days at a time.
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Post by glc on Dec 31, 2009 17:20:22 GMT
What is their definition of a cold winter, and what is yours? Probably that explains the difference...
This is the key to interpreting what's going on. It's not just a case of whether it's cold - but how cold. December 2009 in the UK is colder than average but where does it stand compared to the average. Is it 1, 2 or 3 SD below the mean.
Raveninghorde says
We've heard some people suggest the chances of a cold winter in the UK are now as low as one in thirty due to climate change.
I very much doubt that a UK December average of ~3 deg only has a 1 in 30 (~3%) chance of occurring - even with climate change. If we allow a 0.2 deg per decade increase due to global warming, then I reckon December 2009 is around a 1 in 10 event. Now it is true that last December was also a bit colder than normal (about a 1 in 7 event) but you need to be careful about combining the probabilities. The 2 events might not be totally independent for a start.
aj1983 writes
Currently the NOA index is strongly negative. It has been a long time ago since ....
In 1995 and 1996, the Arctic Oscillation was negative and the UK had 2 cold Decembers, i.e. average temperatures of 2.3 deg and 2.9 deg respectively. It could be argued that despite the current very negative AO we're still not as cold as 13 years ago. We need to see how things play out in the next couple of months.
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Post by raveninghorde on Dec 31, 2009 17:34:03 GMT
What is their definition of a cold winter, and what is yours? Probably that explains the difference... This is the key to interpreting what's going on. It's not just a case of whether it's cold - but how cold. December 2009 in the UK is colder than average but where does it stand compared to the average. Is it 1, 2 or 3 SD below the mean. Raveninghorde says We've heard some people suggest the chances of a cold winter in the UK are now as low as one in thirty due to climate change. Correction. I quoted: theweatheroutlook.com/Who said ... And please note the discussion is about UK snowfall so data for December is not that significant as most snow here is January/February.
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Post by sigurdur on Dec 31, 2009 17:51:05 GMT
IT would seem that, if in fact, we have warmed .70C or so the past 100 years that, at least in the UK, people like the warmth.
Would you agree with that?
When the temp drops to a 1970-1980 level, people think it is quit cold. Imagine if the temp dropped to earlier levels?
Once again I will state that warmth is man's friend. Cold is just.......cold.
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Post by stranger on Dec 31, 2009 21:42:35 GMT
Today's ROFS map shows the Gulf Stream taking a sharp right off Savannah, Georgia, (61.32 W, 31.4 N) and then forming a phase interference pattern on a northeasterly course, splitting into two parallel streams before dissipating on the west side of the mid Atlantic. If this pattern continues, the UK will have a pretty chilly winter. polar.ncep.noaa.gov/ofs/viewer.shtml?-natl-cur-0-small-rundate=latestAnd a late spring. Stranger
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Post by sigurdur on Dec 31, 2009 21:49:20 GMT
I wonder if there is a relationship to this and the burst of hot water of the NE coast of the US/Canada earlier.
Remember, the sst showed a real hot spot about where the stream is diverging.
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Post by glc on Dec 31, 2009 21:55:53 GMT
Correction.
I quoted:
theweatheroutlook.com/
Who said ...I thought I'd replied to this already. I must have forgotten to submit it. You are right the "1 in 30" quote was a quote from the link you provided - not a quote by you personally. Apologies. And please note the discussion is about UK snowfall so data for December is not that significant as most snow here is January/February. That's not too different to what I said, i.e. "We need to see how things play out in the next couple of months."
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Post by nautonnier on Dec 31, 2009 21:59:37 GMT
Today's ROFS map shows the Gulf Stream taking a sharp right off Savannah, Georgia, (61.32 W, 31.4 N) and then forming a phase interference pattern on a northeasterly course, splitting into two parallel streams before dissipating on the west side of the mid Atlantic. If this pattern continues, the UK will have a pretty chilly winter. polar.ncep.noaa.gov/ofs/viewer.shtml?-natl-cur-0-small-rundate=latestAnd a late spring. Stranger Yes - this model has been showing a very weak if non-existent Gulf Stream since early November. The delivered wisdom is that a lot of fresh water from rain/melting ice in the Arctic could stop the thermohaline circulation - however this amount of melting and rain does not appear to have happened (it all fell in Cumbria). Of course we have PDO and NOA shifts now and I don't know if anyone has done research on the effects of these switching states on the Gulf Stream or thermohaline circulation in general. I do hope someone is collecting the raw _unadjusted_ data
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Post by poitsplace on Jan 1, 2010 0:43:11 GMT
Ah the joys of looking at climate through a microscope for the first time (lots of data over a very short period of recent history)...and assuming you knew all along what was causing everything. I'm just dying to know how this and the next winters play out. It's looking like ...while temperatures have increased... the drops in snowfall over the warm period were more related to the stability of the polar vortex. It's especially funny watching "the science is settled" people scrambling to explain why the relationships they said were solid science...are no longer working.
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Post by aj1983 on Jan 1, 2010 4:46:15 GMT
I don't care what the winters look like in local areas, even if we'd get an Elfstedentocht here in the Netherlands this year. The chance of one becomes increasingly lower (although rather slowly), but does not rule out anything. Global projections are global yearly averages. If we'd see a prolonged trend of cooling or strong deviation of the projected AGW trend, things would start to get interesting. Maybe in 50 years we'll think what the heck were we talking about back then, but currently, I wouldn't bet on it.
Which relations do not work anymore??? Why??? The only deviation I see currently is a slower or halted warming trend the last few years, which would be strange ONLY if you assume that the temperature MUST rise exactly 0.2 degrees every decade (actually if you look at the actual global decadal averages it still fits this trend quite well!). I don't think this is what AGW projects, does anybody? The current temporary "halt" is however interesting, because we can analyse natural variability and the magnitude of other forcings besides CO2.
Personally, I would reconsider AGW if we'd get another globally cold period (as projected by many skeptics, a global cooling of about 2 C by 2030). Then CO2 forcing is probably weaker than thought, or natural variability much stonger or both. Or if there would be some really convincing research showing a major flaw in the AGW CO2 absorption physics, or climate sensitivity.
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Post by raveninghorde on Jan 1, 2010 10:35:28 GMT
Personally, I would reconsider AGW if we'd get another globally cold period (as projected by many skeptics, a global cooling of about 2 C by 2030). Then CO2 forcing is probably weaker than thought, or natural variability much stonger or both. Or if there would be some really convincing research showing a major flaw in the AGW CO2 absorption physics, or climate sensitivity. A 2C colling trend would be a dramatic cooling by 2030 more than enough to convince people the ice age is coming. Even 0.5C would be adequate proof that CO2 is not that important.
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