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Catacol

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Catacol last won the day on September 11

Catacol had the most liked content!

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  • Gender
    Male
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    Wellington, Somerset
  • Interests
    History, Rugby, Cricket... and snow. World of Tanks ain't bad either.
  • Weather Preferences
    Frost and snow. A quiet autumn day is also good.

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  1. Relative AAM tendency still running a positive gradient, and ocean temps out west will be conducive to low pressure development as others have mentioned. Factor in a fragile looking jet (some impact of low solar?) and we have a recipe for sharp swings. AAM tendency will not favour a flat pattern, so ridging very much in the mix...and consequently also systems within troughs are likely to develop well, especially if of tropical origin. It's all pretty good watching....especially as September is often a rather quiet month for weather watching. Skimming a few of the other threads I'm left of the same opinion as others, namely that early signs for the winter season ahead are anything but dull looking. The vortex looks likely to be slow in taking off....solar factors are in favour, eQBO is holding on by its finger tips, ENSO is neutral to slightly positive (better profile than last year probably) and the huge melt of ice on the European side of the arctic may favour significant blocking through the autumn right where we might want it to promote snow and cold build up over Russia. Very early days, but despite a statistical correlation for a lower probably of a SSW this season compared to last other drivers may work effectively to produce a good season. Still waiting for rain here, but I dont think it will be far off now. Summer at an end even in the SW.
  2. Catacol

    Arctic melt Season 2018

    Because in simple terms most scientists agree that the globe is warming and that mankind holds (some) responsibility, whereas the number of those who see the temperature record of the last 60 years as representing nothing more than a reflection of natural processes within "normal" bounds are in the minority. Majority rule and hardly surprising. Does it bother you?
  3. Yes - I think I need to retract part of my comment from yesterday - I've been wrestling with inadequate data for a while and got a bit fed up with it, but today have now worked out access to WDT style charts as well as the excellent Gensini site. (Message to self - never post without checking the data more carefully...) Relative AAM is currently spiking, and quite significantly. AAM forecast over at Gensini's site is similarly impressive This should support a much less "flat" pattern in the final third of the month and with the atlantic trough in situ the chance for some long draw SW air returns, though as ever the exact placement of the ridge will be important. Scandy high territory? With atlantic storms in the mix we have some good watching for the time of year coming...and that pesky SW airstream wont cook us in late September either Still badly need some rain though - wouldnt mind seeing the extended ECM op runs at the moment, toying with wet tropical airmasses arriving on the scene, coming true.
  4. ECM is certainly interesting at the moment - ensembles projecting more atlantic influence inbound than their seasonal forecast run on 1st Sept suggested might be the case, and I would agree that all that warm water to the SW might help spawn early pockets of autumnal activity. Quite sharp SST gradient out to our west too....and with pacific forcing currently unremarkable flattish activity pushing ever closer to western fringes looks possible. Too early to get particularly excited about the forthcoming winter season, but the number of weather extremes we seem to be experiencing globally now suggests plenty to keep us entertained. I worry for my children in terms of global climate trends...but from a selfish angle a melting ice cap and impact of bottled warmth in pockets around the world means we can expect the previously unexpected. The incredible destruction of the vortex last season with easterly winds nearly circling the globe will live long in the memory, even if they were so extreme they conspired to end that siberian blast earlier than was expected. In another 3 or 4 weeks we can begin the traditional dissection of long term drivers. Noone will get it absolutely right - but it is fun nonetheless.
  5. Have to admit - dont remember it specifically...but Nov, Dec and Feb were all very mild on the CET record and only Jan held to close to average. Snow that I remember in Dorset was 1996... but maybe there was a 1995 event too. Figures on their own can be deceiving....
  6. Oh great..... winter 1994/95 was a tale of 4 months of mild...
  7. I reckon not. Positive by the end of winter, but not Oct-Dec....though that is largely a guess
  8. Afternoon all - back from holiday (which was hot ) to a UK that is still pretty warm ( ) but to a distant countdown to autumn ( ) On a more serious note....where are we with the shift to El Nino and timing of coupling to the atmosphere? Without back copying my very infrequent posts earlier in the summer my only real interest at the moment has been to ascertain the likelihood of a coupling before summer's end or whether we would need to wait until September. I had a lingering sense that the pacific temperature profile wasnt warm enough to force an atmospheric response yet, and that a slow moving MJO might be too slow to help add a westerly input in the tropical pacific. I mentioned the pattern might, therefore, flatten out through August. One thing I'm going to have to do is find some new tools for the next winter season, because my links/bookmarks seem to be drying up and failing, and getting free access to GSDM plots is becoming difficult - but 2 images worth posting from the functioning links I do have: Global relative AAM (GLAAM) would appear to be stabilising longer term at around +1 according to these CFS plots. Consistently any dip to 0 or below is being seen as temporary as we work through August. Our current MJO is of reasonable amplitude, and by the end of August has worked its way into the pacific phase 7to add convective westerly anomalies into the mix. Conclusion? The pattern is going to flatten out a bit because we have lost the AAM spike that went from -2 and +2 in short order and forced the meridionality we are now seeing. However if AAM stabilises at +1, the MJO makes progress through sympathetic warm waters and the Nino profile continues to build, then I think we have our Nino coupling before we get to the start of the next school term. It may even be in place now. This would enhance the probability of warm weather returning given the current position of a rebuilding Azores/Bermuda High. However probably not as warm as we have seen because AAM will be purring along rather than spiking. What does this mean for the autumn? That's the hobby based thinking I'm shortly about to get underway as this summer fades out...
  9. Sharp rise in GLAAM that kicked off around 4th July now impacting on the atlantic pattern, with a much more meridional feel on the horizon. This is the path for the next 10 days Beyond this all to play for. From a personal note I'm interested to see if AAM increases and the current MJO wave move the atmosphere into more of a Nino pattern longer term, or whether enough residual Nina remains to hold off a global shift. It looks like fine margins to me. Pacific temperature profile is neutral but forecast steadily to rise. MJO wave is the biggest in a while, but may not make progress into the pacific as quickly as expected using norms. Ventrice notes, using NOAA data, progress of the kelvin wave through the atlantic and towards Africa through late July - will this help reduce the azores high and give the atlantic trough more legs via westerly wind bursts and undermining of any azores influence? In conclusion - short/medium term looks like a Nino style pattern giving heat, instability and thunder storms. Longer term into August? Uncertain. If GLAAM flattens then so too will the pattern.
  10. Transition from a prolonged period of low AAM to one where we have a slow moving pacific wave gathering some strength and adding positive momentum to our part of the world was always going to create some NWP uncertainty. I wouldnt bank on any more meridional style pattern necessarily remaining for long - forecasts are continuing to water down the extent of the AAM spike, and I wouldnt be surprised to see a reset into an azores dominated situation by month's end. Having said that I have come to the conclusion that forecasting the pacific profile is far from simple and trends are a long way from specific outcomes - so we could still maybe get a dramatic spike and then a second half of summer with a lot more north/south influence to things than we have seen of late. It was said before that developments in the first half of July would define the rest of summer, and we still have a few days to go before we get to the 15th!! All still up for grabs.
  11. Interesting to see the GFS forecast of pacific activity get ever more vague. The relatively tight clustering of GLAAM forecasts a week ago have descended to apparent confusion Models struggling to pick up pacific trends with any certainty, so NWP output beyond 10 days is definite fantasy at present. Given lag times we could possibly see a very different atlantic profile if Nino imprints on the atmosphere at that point. Looking at longer range trends it can only be a matter of time before it does....so if not mid August then certainly in September I think. More continental instability and thunder storms would represent a welcome change.
  12. NWP will be struggling with mixed macro signals right now - GLAAM is spiking, but variance in forecast output in the last few days makes in unclear just how much energy will be pumped into the atlantic. Also the MJO is growing, but forecasts are confused as to speed of progression and NOAA reports talk of a fairly static and slow signal over the next 2 weeks. The pacific profile is unexciting at the moment - no dominant signal at the equator. End product is a trend that should really be promoting a more amplified pattern according to GSDM expectations, but the atmosphere is not ready quite yet to lose its Nina state. End result I suspect will be a pattern that will bring more unsettled weather to the north, but an azores ridge that will remain strong enough in situ to give the south some good extended conditions. Agree with a few posters that heavy thundery showers may come into the mix on top for the south, with the spike in GLAAM helping the Euro ridge to border on a scandy one... with lower pressure over central Europe. With the right alignment here plume activity as we move closer to the end of the month is a possibility.
  13. Yes - I really like this bit. I am lining up some reading over the summer once I get a break from work to be stronger in my grasp of these macroscale events. Interesting to see the 365 day progression of GLAAM The very obvious oceanic Nina imprint on the atmosphere is clear throughout, with GLAAM sitting mostly below 0 and often tipping towards -2SD. Note the small peak in November that gave us early winter ridging, a bigger peak in December that got a few of us excited (including me) but was then countered by the very steep drop off after Xmas - and then note the massive spike from -2SD up towards +2SD in the space of a couple of weeks in early Feb that gave a total increase of 4SD, smashing the vortex to shreds and giving us that memorable March. Note we now sit in a very low period of GLAAM when looked at across a full year. I guess the question is - are we about to see another major spike that will serve to disrupt the base Nina state? With the ITCZ sitting further north in summer than it is in winter currently we have a very benevolent low AAM pattern promoting the azores ridge as sub tropical high pressure belts are dominant. If westerly momentum is inserted at the tropics via the next developing wave, then we can expect a more meridional pattern to emerge and our current ridge to push further north. As ever the big question, should this occur, will be: will the expanding ridge trough pattern place the uk on the warm dry side, or the cooler/wetter side? Will be interesting to watch things unfold. Of far greater interest to me though is the potential end of a long phase of Nina. With the pacific definitely warming up the end of Nina is nigh. The timing of this will again be very interesting to watch, and for those with an interest in the autumn/winter this is a very important development too.
  14. A great post as ever Tamara - as I come out of hibernation long enough to blow my nose for the zillionth time this last month, search for a cool patch anywhere in the house, and pray that rain might come to save the garden. Ugh. I make no secret of my utter loathing of hot summer weather. In my book, if you want it hot go to Greece. Anyway - why my first post in a long while? Well - aside from the fatigue of a long winter season on NW crowned with the excitement of March I have also been watching the pacific on and off through Spring, wondering just how the engine room of the planetary weather systems might view summer 2018 with knock on effects into the winter. MetO forecast now is fairly bullish as to a move towards El, Nino Region 3.4 emerging round about now from neutral to slight positive, with a gentle gathering up towards +1 by the time we hit mid autumn. As Tamara states - if we are to get a coupling of the ocean base state with the atmosphere which has retained a Nina blueprint for a long time now then we absolutely must see a significant rise in GLAAM. It cant happen any other way. ECM MJO forecasts clearly show the spaghetti heading towards a phase 5 orbit as the MJO hits the pacific and JMA's July MJO composites clearly show the strong atlantic ridge supported by this evolution through phases 5 and 6, assuming this MJO gets out of the COD So - will we get a Nino orbit as potentially suggested above? Knife edge. I am uncertain that a very neutral ENSO appearance through most of July is going to bring that ocean/atmosphere coupling into a Nino phase quite yet - Schraldi plots with their well known low AAM bias are unexciting and unless the Nino grows in strength faster than either the Met or the CPC are expecting then any impact looks to me to be towards the end of summer and into autumn. If that is the case then one would expect the pacific to reamplify via an unimpressive MJO phase with the likely result of the UK ridge replaced with some kind of UK trough. However the water in the equatorial pacific is warm from west into centre (Nino 4 through to Nino 3) suggesting the MJO could possibly grow through phases 5/6/7/8... and it is not beyond the bounds of possibility therefore that July sees a tropical surge with consequent impacts in the sub tropics, namely suppression of the pacific ridge with consequent downstream impacts that might see the Euro warm spell continue. After all... look what happened in February. No polar vortex to worry about in these summer situations. Less complex.... but still complex enough to ensure that long range weather forecasting is fraught with difficulty. Where Tamara is spot on in my opinion is that the evolution of conditions in the pacific through the first fortnight in July is likely to dictate the course of the rest of the summer. Meanwhile my T shirt is now sticking to my back and the only solution to this misery is another cold shower. Hooray.....
  15. Hehe - go on presenting! I wasnt having a dig... just dont understand the wringing of hands over perceptions of an event that has barely started. Stuff the models and the radar now - enjoy what's through the window everybody. If staring at radar and high res model runs is your cup of tea while flakes are in the air outside, then this whole snow hunt thing has become rather warped. March 18 is delivering some snow.... could be 5cm, 10cm or 15cm. Could be more... nobody will really know until tea time tomorrow and that's the fun of watching it fall.
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