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About Catacol

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  1. Jump across the pond. Over here in the UK we continue to experience extremes. Having had one of the wettest winter periods on record we have now had over 2 months with hardly a drop in southern England, and it would appear southern England is now on course for the driest May on record. In my locale we have had one day of proper rain since mid March. And it has been warm too - far too warm for heat haters like me. Summers getting hotter and drier. Winters getting generally milder and wetter. Grim.
  2. Ha - certainly hope so. The positive follow up to my slightly gloomy post is that the UKMet are not always correct - see Jan into Feb 18 as an excellent recent example, and for that matter Jan/Feb 19 when the constant calls for imminent cold produced one of the mildest February CETs for many a year. In general though they are developing an irritating habit of getting the North Atlantic pattern right. Your North Pacific ridge holds the key that might unlock a - NAO or possibly a Scandy block. Shortening wavelengths into February should help, and for all the disappointment of the last 4 weeks over here the fact remains that solar is low, SSTs are broadly favourable and the QBO has turned, though QBO pre conditions will be much better in 20/21. There is enough here for optimism and it is still only 9th January... But while the MJO doesn’t tell the full story of Pacific forcing I can’t help feeling that if it doesn’t get itself into decent amplitude 7/8 the vortex in its current form is going to remain in charge. Eric’s long post the other night (which was excellent by the way @Webberweather) was massively informative but filled me with caution. No certainty of a progression through and beyond the maritimes...
  3. Source inside UKMet punting for tight cycle back towards phase 4/5 with no substantive progress into 7. Some positive signs that the end of the month can to be as flat as the current pattern, but much to happen before amplification can kick in properly. Hoping Anthony’s Okhotsk Bowling Ball can deliver something to act alongside next momentum spike. Meanwhile temps here are about average for April...
  4. Let’s revel in the pain. GEFS 2m anomalies for Europe mid month. Parts of the east up over 8 degrees C above average = no hope whatsoever of the NW and UK getting a sniff of winter anytime soon...
  5. ...and perfect contextual conditions for warm weather records to be broken (again) in NW Europe. Potential there for air from Casablanca to reach the Cairngorms. Yikes....the genuine crumb of comfort is that it is impossible to find a worse ridge alignment and end product than that for UK winter. It absolutely has to get better from there.
  6. For what it’s worth UK forums continue to wave the white flag. GEFS and EPS height anomaly over Scandy lacking in resilience is the majority call, and certainly JMA monthly backed this. I’ve come over here for a bit of sanity as there is a little more optimism to be found, but it is tough watching/interpreting right now with the tropospheric vortex in such control and a lack of conviction in the ability of Pacific convection to spike the pattern properly. Searching for crumbs of comfort to be honest, and can’t help feeling that when long range GEFS is the crutch that is being pulled out to support a change then odds aren’t great. However on this side of the Atlantic also the Scandy ridge is also seen as the key to any change. As with NE USA and a Greenland Block a Scandy Block for the UK can pull colder air in from the NE...and if it is cold enough then the North Sea can create lake effect snow, particularly along the lines of major rivers. Trouble is....there’s next to no cold air over Europe to be found at the moment as the Euro High over France pumps warm Spanish/African air up over the NW of the continent and into Scandinavia. Horrendous. But a wave 2 tropospheric pinch pushing up into the stratosphere is the best hope at present. Might begin to weaken support for the +AO pattern which is gripping us all at the moment.
  7. Hmmm - tasty looking wave 2 pinch that might force some positive changes. Perhaps my winter forecast isn’t dead after all.... Thanks @PB GFI
  8. Yes - began to show yesterday. Fingers crossed. Wonder what EPS shows. Anyone got a long range weatherbell anomaly for the same time they can post (without breaking rules!)?
  9. Yep good reply and question. I wouldn’t dream of claiming substantive knowledge/understanding of the stratospheric vortex and so my musings are strictly of the interested amateur type. But my observation from years of watching (and a fair bit of reading of those with real knowledge ) would be that a permanent dance is conducted between stratospheric and tropospheric vortex, a simplistic representation of the relationship between multiple layers and frictional forces between them. In essence I have read a lot of discussion around the nature of the dance relationship - is the dance led bottom up with Pacific forcing creating tropospheric wave patterns that create upwards forcings and therefore a tropospheric lead? Or is the relationship more top down....with frictional downwelling the key component in the relationship and able to guide the tropospheric wave pattern. The truth is that the relationship probably ebbs and flows....but my own observational view is that downwards propagation generally holds the whip hand. There are always examples of the opposite - take Nov 2019 just a few weeks ago. Decent Euro high anomaly created by supportive Pacific forcing was able to create enough upwards wave flux to create a short lived blocking pattern over Western Europe and some happiness at early flakes of snow over Alps and Scottish Highlands. The vortex here was disrupted from the bottom up, and almost certainly aided by the fact that In November the seasonal intensification period is far from complete, The November vortex is always vulnerable. But a late December vortex is a different beast, and I see very little evidence in recent years of upwards propagation impacting in vortex formation at this point of the winter....and therefore there are considerable implications for January and February patterns if the vortex gets well established. Feb 18 is a wonderful example of how the vortex can be crashed from an almost freakish north Atlantic dipole event that shot it down - and the downwards propagation of the split and anomalies in that season was a joy to watch. I have never ever seen a reversal at around 65N that saw an air flow from Siberia to Canada the wrong way via Europe before....but the dying vortex brought us that incredible event (now officially recorded as the most significantly impactive SSW for European temperatures since 1979) BUT the key here is that vortex was already in decline. For the North Atlantic basin the number of cold weather events in the “heart” of winter (late Dec and all of January) caused by tropospheric wave patterns encouraged by Pacific forcing is becoming a very small number in recent years. In addition I’ve read the temperature gradient argument leading to more blocked patterns, but I’ve also read that argument shredded. This article suggests that alteration in temperature gradient at the equator is more important than at the pole, and instead sees a reduction in some key elements of northern blocking. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016GL069725 Certainly over Europe Greenland and/or Scandinavian blocking is observationally becoming a rare event! I guess therefore I would modify my argument to state that the impact of a cooling stratosphere with downwelling positive westerly anomalies is set to create a less conducive cold pattern in the core of the Northern Hemisphere winter, but that this forcing is inevitably less significant in November and in late Feb/March. Interestingly the 2 coldest winter spells in the UK in the last 9 years have both been in March. The coupling I refer to is therefore observational (sample of one = me....and based upon around 20 years of significant weather interest....not very long in the grand scheme of things!) but for now I’ll stick to it...and as a result I think winters are going to get milder because the core of winter cold is likely to be accompanied by dominant downwards propagation of westerlies. This is probably most obvious over here in Europe where we are experiencing significant downstream impacts of vortex intensification events centred over the North American continent but I suspect it may be a trend that becomes significant elsewhere. Any rogue factors? North Pacific warmth. Everyone is spotting the impacts of this....and as I said in my original post this could be a driver that breaks the pattern in the future if a new ocean phase arrives. Anyway good debate to have. Don’t worry about starting an argument - my profession is historian and sports coach,,,,and as such I live and breathe debate. And a final addition to the gloom of the 2019/20 season. All time Norwegian temperature record broken yesterday. 66F (which is 25 degrees Celsius higher than monthly climatological average.) Not many happy snow hunters over here on the other side of the Atlantic. Whenever you guys are feeling gloomy spare a thought for the horrendous run of NW European winters in recent years (unless low energy bills floats your boat!)
  10. A number of things seem to be happening. We know the convergence zone is gradually edging north, probably a product of climate change. This means the Euro high is becoming a warmer high. Simultaneously stratospheric temperatures over the pole are becoming colder, a product of increased CO2...and this means that the stratospheric vortex is stronger, and coupling to the troposphere is enhancing the westerly climatology and preventing high latitude wave breaking in the heart of winter occurring effectively over the North Atlantic. This is being further enhanced by consistently warm waters in the North Pacific creating an almost semi permanent Alaskan ridge - see Alaska temperature records. Downstream US trough is more frequent, and in winter this means enhanced cyclogenisis over the Atlantic as cold Canadian air further whips up those westerlies. Put all 3 elements together and it means the amount of Pacific forcing needed to displace the Euro high northwards is increasing, and in truth over the last 20 years it has become rare. So the Euro high grows in frequency and at the same time the warmth within it grows. I’m not sure there is much hope of a substantive change to this as far as the eye can see. A cooler North Pacific would alter things a bit and perhaps encourage less vigorous systems to eject from North America - but there seems no end in sight to falling stratospheric temperatures enhancing the upper vortex or the northwards movement of the sub tropical high pressure belt as the world warms. Ultimately winters in Europe are going to become increasingly mild, episodes of reverse flow due to substantive wave breaking in winter will become rarer and vortex enhanced westerlies originating from Greenland / Canada will dominate. The Euro High has always been a common winter feature, but as we are seeing yet again this winter it is going to be a bigger and bigger player. For the UK this means wetter winters in general. Flooding is becoming an annual problem. The only answer unless an unforeseen shift occurs is to move house. Given the imminent disaster of Brexit that has a curious attraction....
  11. Lots of gloom over here in UK/Europe. Mention of the infamous 1988/89 winter starting to do the rounds.,,,and reports that ski resorts in the Alps are making preparations to move snow to higher altitude to try and preserve what they’ve got from melt. Azores High firmly fixed in place and low heights over Greenland and E Canada ensuring a strong +NAO feel to the Atlantic. Images like this from the JMA not helping to improve the mood. Note SE US ridge and Euro High ensuring a very flat Atlantic forcing. All eyes on the latter half of January and whether anything from the Pacific can jolt the long wave pattern into something more favourable. Right now, in an era of climate records, the UK could possibly be staring down the barrel of a near record January at the “wrong” end of the spectrum. Temperatures in the Scottish Highlands reached a night time record of 65F last weekend (previous record set in 1948) and I have a feeling this new record itself may not be long lasting....
  12. Thanks Pulsar. Not a happy picture for NW Europe where increasingly warm weather seems to be the product of changing climate...
  13. @Webberweather - does this chart make you feel smug?! Is this evidence of a clear shift towards the Nino background state you were touting?
  14. Yes - and for the Atlantic this would fit with the relative AAM plot posted above. Note the ever so faint suggestions of jet undercut to the south of the UK high. Things getting interesting, though by 13 Jan the peak of the momentum surge will have passed and is the pattern likely to flatten out again?
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