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chionomaniac

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Everything posted by chionomaniac

  1. chionomaniac
    Ha! Well that will keep Father Christmas on his toes won't it? Never been woken by thunder on Christmas morning before. Three loud bangs so far!
  2. chionomaniac
    I would tend to agree with this as well Nick. Certainly, the drive home last night was in atrocious conditions with rivers on the roads. And I am still in a bit of shock thinking there but for the grace of God go I, when looking at the tree that came down just before I left work yesterday in East Grinstead. It could have been very different.
  3. chionomaniac
    I think that the main roads are Ok, Robin, and have been cleared. Looking at the radar it won't be long until the rain band clears leaving just showers. I certainly don't envy those in flood risk areas.
  4. chionomaniac
    Morning. I have just been out to collect the turkey from a local farm in Hurstpierpoint. Still bad conditions out there on the roads. The farm was down a small lane that was blocked by fallen trees at one end and the brook was close to flooding the other as it was backing up under the bridge, with streams on the roads further adding to the water jam. I have not looked locally on the news, but I would not be surprised to see some significant flooding before the end of the festive season. Keep safe all.
  5. chionomaniac
    Here is the A22 earlier by the speed camera Normally backed up with traffic - luckily not so tonight when that tree came down.
  6. chionomaniac
    It was really bad down that way on my way home tonight - do you live on the road to turners hill nr where the stream goes under the bluebell railway? I wish you all the best as having driven through there earlier I can imagine how bad it will be. Still a fair bit of rain to come I'm afraid.
  7. chionomaniac
    Here's a pic of a tree outside my work on the A22 in East Grinstead. Normally this road is stacked up in both directions at the time that this tree came down completely blocking the road around 6pm. I feel that there has been a lucky escape here. (sorry about the quality but it was blowing hard and absolutely chucking it down.)
  8. chionomaniac
    Without the help of the ECM wave amplitude charts, the shape of the vortex is a dead giveaway. With wave 1 type events the large scale wave presses onto the vortex from one side and the vortex will look like a big comma shape. With wave 2 type events the vortex will look elongated - like a sausage, with 2 sources of warming evident on opposite sides of the hemisphere.
  9. chionomaniac
    That is quite a big wave.... and could really do some damage to the vortex, sk. Highly promising this forecast for (comparatively) early in the New Year. I know I did suggest strong wave 2 activity in Jan to overwhelm the vortex by Feb - but I am even surprised by this forecast.
  10. chionomaniac
    Yes - as described by: McIntyre, M. E., and T. N. Palmer (1984), The ‘surf zone’ in the stratosphere, J. Atmos. Terr. Phys., 46, 825–849.
  11. chionomaniac
    It effectively means that even though the vortex is stretched by the wave 2 activity, it never really loses its strength. So when the wave activity reduces the stretching reduces with it and the vortex is likely to retire back to the pole. The warming never really penetrates through the surf zone and into the core of the vortex and this is critical for those hoping to see the strength reduce significantly. That isn't to say that that won't happen in future runs - it's just not being forecast presently.
  12. chionomaniac
    Latest GFS run we again are seeing the stratospheric polar vortex coming under intense wave 2 pressure - not enough to break it mind you - it will be very much the case of the distorted balloon that reforms when the wave 2 pressure decreases, but the vortex will be riper for breaking should we get another burst of wave 2 activity later in January. Certainly worth watching but note that the lowest heights at 10 hPa and 30 hPa remain the same throughout the run.
  13. chionomaniac
    Interestingly, it was another of those events when a large warming occurred but these did not meet the WMO SSW definition. I know that there has been some discussion regarding significant strat warmings that do not reverse the mean zonal winds at 60ºN and 10hPa, but yet can have a considerable tropospheric response. It appears that this is on the agenda at SPARC's (Stratospheric Processes and their Role in Climate) meeting next month, so that this ambiguity may be addressed. Here is an excerpt from the latest general email : Dear colleagues: At the recent SPARC DynVar meeting in April 2013, there was much discussion about how we, as a community, define sudden stratospheric warmings, and in particular if the standard SSW definition (i.e, the WMO definition) are adequate for current needs. The main reasons for doing so are: 1. The definition was developed in the 1960-70s, based largely on the observation system at the time (radiosondes/rocketsondes). It therefore does not take full advantage the more comprehensive observations available now. 2. Our theoretical understanding of SSWs has also matured considerably in recent decades. The definition could be improved to include, for example, differences between split and displacement type events, or guidance on how to determine independent events. It could also include an element related to stratosphere-troposphere coupling. 3. A number of new diagnostics have been proposed in the last decade (in addition to different interpretations of the current WMO definition), leading to inconsistencies in the classification of major SSWs depending on which diagnostic is chosen. While different diagnostics may be useful for different applications, having a standardized definition available is an important tool for the research and forecasting community. A formal definition creates a standardized method for forecasting SSWs; allows for a standard set of major SSW events in research; and gives a consistent way to evaluate simulated stratospheric variability in both historical and future climate scenarios. We are organizing efforts to update the original WMO definition for SSWs, based on present-day observations, more complete understanding of the phenomenon, and the changing needs of the community. We would like your input about what the community wants from a definition and how it will be used. For example, is it important to classify SSW onset in real time? Would it be more useful to focus on the stratosphere-troposphere coupling of an event? Is it important to keep the definition simple to calculate and based on fewer variables? The first opportunity to meet will be the *SPARC General Assembly* in January 2014 in Queenstown. Amy Butler will be presenting on this topic on Tuesday afternoon, and we thought it would be useful to get input after that regarding our proposed method and timeline for updating the definition and engaging the scientific community. *We will be meeting during the lunch period on Thursday January 16th (12:15-2pm, *in the Millennium Hotel). Hopefully we will see some clarification and further definition on the subject.
  14. chionomaniac
    This is the reason that I have said that a SSW is not out of the question this year - the previous statistics do suggest that some type of mid/late winter warming is possible. It is interesting to see that latest uptick in forecast wave 2 activity to begin around the start of next year. My thoughts are that the vortex will recover from this, but be more susceptible to further wave activity later in Jan /Feb.Stratospherically I think we are seeing no surprises whatsoever this winter, but this forecast wave activity does need to be monitored just in case we see a bonus surprise.
  15. chionomaniac
    That question is far too difficult to answer simply, SI!
  16. chionomaniac
    I didn't delete it but would have done. This is a family forum with younger members and there is no need to try and bypass the swear filter, humourous or not, thanks.
  17. chionomaniac
    Hi OldMetMan. The temperature change seen on those Japanese model do show a slight warming over Asia as a result of the recent increase in wave activity over this region. This has remained at the surf zone and has not penetrated the vortex - a far greater amplitude of wave would be required to disrupt more. The graph that sebastiaan has posted from the Italian research suggests that they forecast a far greater amplitude of wave activity for February and it will be interesting to see if this will be enough to disrupt the vortex.
  18. chionomaniac
    Thanks for the great link, Sebastiaan. From reading that it would appear great news that Judah Cohen has approached them to enter a future collaboration. It certainly seems that they are onto something and this could be groundbreaking for long term winter forecasting. Note the colder February hinted at for the UK but stong vortex conditions likely early Jan. The thing is, and this is more regarding longer term forecasts, is that I feel we have been close to making a breakthrough for a while now and the work of those such as Stewart Rampling who have always suggested that long wave patterns are not simply random, but can be predicted and re-occur time and time again when the starting teleconnective conditions are the same will be vindicated in their thoughts. The Italians seem to been able to analyze the autumnal vortex conditions and have used this to be able to predict the following winter vortex state, And so far this winter their prediction correlates very well. It is a pity that we see so many longe range hopecasts out there that do a lot to denigrate from the work of the true researchers. The Italians work still has to be published and peer reviewed and so until this occurs we should be more cautious, but the fact that they have predicted this winter in advance will give us some kind of mark to judge the authenticity of their work without peer review. Interestingly, their own winter forecast does fit in with the previous analogue composite years that I have used to base NW winter forecasts - again, it will be interesting to see how this plays out as I am a strong believer in the predictability of repeated patterns and that the butterfly effect may not be quite as true as initially thought .
  19. chionomaniac
    That's 100m/s which is around 224mph........ Remember to check the scales, Tony!
  20. chionomaniac
    Good post Recretos. I suspect that if the vortex is to be broken then it will not occur until well into the new year. However, the increased tropospheric/ stratospheric wave activity feedback is starting to show. Initially, the warm air rides the 'surf zone' and fails to break through and hence the distorted balloon look of the vortex - but like a distorted balloon once the pressure from the wave activity reduces, the vortex quickly resumes its shape. We do often see quasistationary type 1 waves, that keep the comma shaped distortions for periods of time, and these can build and build and eventually break the vortex, though I think these are less common with wave 2's. I think my point is as per the winter forecast is that by January, repeated wave 2 activity is likely to put pressure on the vortex and now this is beginning to show at the end of the runs. If this continues will we see the vortex broken in February when it is in decline and the wQBO is reducing..... questions, questions that we are yet to know the answer to......
  21. chionomaniac
    More wobbles from the top on the 12Z: Classic wave 2 activity starting to be predicted to affect the vortex now (right on cue) - but how far away is the performer from respinning....
  22. chionomaniac
    It's best to look at the jet stream charts, TF. http://www.netweather.tv/index.cgi?action=jetstream;sess=6bae1b18f657f66dba7b0af76fd3a14f There are not really any good examples of a split flow or southern positioned jet stream in the current run to illustrate what it is best to look for in order to show energy going underneath a block. Currently the flow across the Atlantic is strong and flat. When the flow meanders, then there will be better examples to show split flows with the energy going over or under.
  23. chionomaniac
    I think that it can be a case of both. In 2008/09 winter we saw a fair amount of fairly strong wave 1 activity that didn't reall disrupt the vortex enough, followed by a strong wave 2 action that caused a SSW. We need to see enough vortex disruption to allow a Scandi high to develop and influence in January. I can't see a SSW until far later than early Jan if at all. (In fact I would rule out a SSW in the timeframe up to 10th Jan at this point. Last winter it was around this time that the signals appeared for the eventual SSW - these were backed up by tropospheric precursor conditions and early warming on the fringes of the vortex that hinted Cohen's theory regarding stratospheric feedback would hold true.) I see the current vortex pattern as similar to a 1980's plate spinning act (another analogy I know). Currently the performer is in control of all the plates and they are spinning fast. One of these plates is our polar vortex. As the performer puts more plates on the rods, ours starts to wobble (that is akin to wave activity) but the performer gets there in time to respin and the vortex regains strength. However, the more plates that he spins the longer he leaves before he returns to our plate (akin to the change in seasonal wavelength and QBO phase allowing greater wave activity to affect the vortex), and our plate wobbles like mad. If he leaves it long enough it will eventually crash to the floor and break (the SSW) and the vortex will be beyond repair until a new plate can be found and mounted. This winter it may be that the plate does not come crashing down, but if it wobbles enough, then we may just see some cold flushing south, but that may take some time to occur.
  24. chionomaniac
    Whereas nothing major is going to come from this wave 2 activity, S4lancia -my ears are starting to twitch as we need to see the first signs of 'wobble' of the vortex for later on in the season. The last few days trop and strat ouputs into FI are hinting at this wobble. The vortex this winter will take some bringing down.
  25. chionomaniac
    Hmmm. 1978 there it is again! West QBO, ENSO neutral, similar solar conditions...... Feb 1979:
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