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Singularity

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Singularity last won the day on September 14 2018

Singularity had the most liked content!

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About Singularity

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    MSc Meteorology

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    Male
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    New Forest (Western)
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    Meteorology - Science and Observations | Cycling - On and Off Road | Walking or Hiking | Electronic Music Creation
  • Weather Preferences
    The Extremes! Passionate Hater of Drizzle.

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  1. Big thanks for your follow-on from my post yesterday @Tamara . Glad to see the trough adjusted west or southwest by the 00z runs as I suspected it would - I can see just enough Nino ‘flavour’ hanging on in the atmosphere to encourage the trough to be over that way instead of in line with or east of the UK. This being how the cycling of the GWO in the positive phases tends to bring about a spring-summertime regime of ridges building near or over the UK, then heading to our east or northeast while troughs destabilise conditions, sometimes with a heat plume involved. Some will grin at this potential. Usual caveats apply of course (such as assuming no major complications arise...).
  2. A step closer when looking at the det. run middle-ground this morning; trough stalling and sliding a little west of the UK. Just needs another thousand miles adjustment west or southwest - something nearer what the 18z GFS showed (a strong match for that run is probably a bit on the optimistic side, sadly).
  3. So now the model runs are dominated by massive retraction west of the subtropical high in the mid-range with a trough of some manner (deep or shallow) dropping in and turning things cool and unsettled for at least a few days. Really bizarre to see that with the ongoing El Nino; it's more fitting of a moderate, maybe even strong La Nina event! The ECM 12z is particularly extreme, a genuine 'what the [strong word]' run for me. As I said earlier today, falling AAM against a +ve background often leads to overblown bursts of westerly momentum across the N. Atlantic, hence 'shove-in' of troughs across the UK. In light of which, I'm still hopeful for a less clean and successful retraction west of the ridge, with more left across Europe and the trough grinding to a halt west of the UK rather than overhead. I've seen that manner of adjustment happen plenty of times before in the 5-10 day range. Should that fail to occur then not only will the notion of an El Nino base state come under serious question, but the long-range modelling guidance will have landed extremely far wide of the mark yet again (for some time, they've been shouting for a notably warm 2nd half to April, which requires more than just 4 or 5 days hitting the high teens to low 20s; more like 9 or 10 - at least!). This would further cement the idea that climate change is significantly mutating the mechanism by which the Pacific SSTs affect the global climate. So I really hope it doesn't come to that!
  4. GLAAM is taking a brief dive before reloading back to +ve tendency as the Nino base state asserts itself more again. I've found the strength of the polar jet's westerly burst across the N. Atlantic to be a bit too dramatic in most of the recent model output; I'm not convinced it will be enough to fully displace high pressure away from the UK. The models often overdo the pattern response to the AAM tendency turning negative while the anomalies are +ve. More of a stalemate seems probable to me, with rain bands from the west or southwest struggling to make it far across the UK. GFS 06z looks a bit of an over-correction to me, unless the Nino base state is now looking to reassert itself more quickly than has been anticipated.
  5. Hi Mike, Good question there. I see the cause for confusion here; what I called the final warming is actually more of a tropospheric-driven lower-mid-stratospheric warming that looks to either set in motion or coincide with the beginning of the final warming in the coming week. A decent dual-anticyclone pattern (wave-2) here - this being what we didn't have enough off back in late Dec and early Jan to produce a pure split-vortex type SSW rather than the messy hybrid that didn't work out well for E&W cold and snow enthusiasts (Scotland's seemed pretty snowy, though perhaps not by their own standards?). Goodbye and good riddance, Mr. Vortex!
  6. Looks like as the final warming-aided HLB spell finally subsides we see a ‘Nino switch’ flipped with a typical struggling Atlantic trough and Scandinavian high combination. Thats the usual predominant pattern with a weak Nino and low solar activity in Apr-July. Settled increasingly warm/hot spells punctuated by destabilisations by shallow troughs which tend to provide some thundery entertainment. Remains to be seen what complications we see from, for example, the cold anomalies in the SSTs just S of Greenland (may keep the jet stronger and HP further S) and the low Arctic sea ice (may enable stronger Scandinavian highs than usual even for the Nino base state, along with more Azores High interplay - if the next few months turn out unusually dry it’ll most likely be the the low Arctic sea ice responsible).
  7. This is the point that too many in high positions of power demonstrate a stubborn inability to accept, regardless of the science. Though I understand that finding the money isn't going to be easy for a lot of countries; some sacrifices will be inevitable if sufficient developments are to be made. I wonder, with all the increased awareness now, how many in the UK would be happy to forgo some luxuries in exchange for combating climate change? I suppose the problem is then achieving enough belief that the climate can be saved, for which enough sacrifice-making needs to be seen, which needs enough belief... a toublesome catch-22 situation. Not necessarily unbreakable, though, so I'm very glad to see Sir David Attenborough taking big strides to increase the level of belief toward that which is needed.
  8. I wonder if we should worry about the 'Methane Bomb' as some call it, beneath the ESS, before the B.O.E. possibility. Years like this, with particularly thin ice in that region compared to even the past decade, and an early build of heat and loss of snow and ice in Siberia, are the most concerning when it comes to that methane store. I've seen its release put down as a B.O.E. consequence but could it instead be what jumps us toward it, quite suddenly? I recently heard (in a video within the 'Just Have a Think' YouTube series) that even a small fraction - about a fifth - of the methane would cause global mean temps to rise more than 0.5*C in just a few years. I imagine the regional impact during the first few months after release could be quite a bit more than that.
  9. https://phys.org/news/2017-05-height-antarctica-slower-arctic.html I happened across this article yesterday from a couple of years ago. It probably got shared on here but in case it wasn't, here's a link. My overall impression is that Antarctica may be more of a 'dam burst' style event if and when the regional temperatures reach some critical threshold. The ice sheet surface starts to lose significant amounts of height, surface and near-surface temps increase accordingly, and losses accelerate in a vicious positive feedback. I wonder, though, if the increasing depth of atmosphere, along with higher temperatures, would before long facilitate an increase in snowfall sufficient to counterbalance the temperature-driven losses? Depends how the relationship with surface insolation works out for ice sheets on a large continent rather than sea ice on an ocean (we know that added snow cover doesn't really help the Arctic sea ice in the long run; sure it may preserve more of it for one summer, but lost thickening during the freezing season offsets this). This may become one of the hottest topics of scientific debate in some 50-200 years time (depending on which projections you look at). While the bulk of Antarctica remains resiliently cold instead, increasing thermal gradients may mean that the Southern Ocean becomes even stormier than it already infamously is. What a thought!
  10. I referred not to sun-driven melt but cloud-driven. I was surprised to learn that clouds had a strong enough effect, soon enough, to affect the melt onset timing, but there's evidence to support the notion. For example: https://www.giss.nasa.gov/research/briefs/delgenio_06/ "In spring, however, cloudy conditions begin to dominate, causing temperatures to warm on average and move the ice closer to its melting temperature, even before the newly risen Sun is strong enough to matter. Thus, more persistent clouds as spring approaches may cause the sea ice to first reach its melting temperature at an earlier date, and more frequent Arctic clouds in a warmer climate might accelerate sea ice decline." It's to do with the increased humidity and scattering + reflection of radiation. I've witnessed this first-hand in the UK when on freezing cold days (literally maximum zero or less), the arrival of some low cloud cover has caused lying snow to begin thawing steadily. The reflected longwave radiation isn't reflected as efficiently by the low albedo of snow. Moving on - on MIA's post, I'm not sure 'recovering' is a valid word for point 2) given that the amount of 3+ year ice has continued generally downward. It seems that individual regions fail to achieve more than a couple of high retention melt seasons in a row. On point 3 a), that was one of the most exceptional SSWs on record for tropospheric impact so yes, it's possible, but requires something truly special and in any case only seems to buy us a little time in the longer run. That being said, an increase in SSW frequency and intensity is a possible effect of reduced Arctic sea ice (due to more extreme jet stream configurations) so you never know! Point 4 d) I've seen come up often in the past few years, with the most common counter being that Fram export is a measure based on volume, meaning that it goes down if the exported ice is becoming thinner as has generally been observed this past decade. On top of that, more and more ice is melting out before it even makes it that far, while the Atlantification of Kara and the area around Svalbard has turned that into an extra melting zone that takes out ice that could otherwise have headed to the Fram region. Despite all that, Fram export increased substantially this year. This is due to wind patterns shifting the thickest Canadian-side ice toward the NE corner of Greenland. We really need a strong reversal of the wind patterns to push that ice away from there; it's the largest area of continuous 3+ m thick ice left on the Arctic Ocean. Ugh - I don't like how much 'doom and gloom' keeps finding its way into my updates here. There's just so many negative findings in research at the moment and so few positive ones! The main positive has been the size of the restriction to summer month melting imposed by the additional cloud cover resulting from increased open waters, which has been at the upper end of expectations. I'm not sure, though, how well this can hold up if and when external forcing brings about strong high pressure development. In the most recent example, July 2015, it was thoroughly overwhelmed - but the amount of anomalous open water has increased further since then.
  11. I would actually go so far as to describe the weather patterns as 'maleficent', despite how illogical it is to assign such a term to an non-sentient phenomenon. It just has that feel to it this year - but then, so did last year, albeit not as strongly. The thing is though, the factors that proved counteractive last year such as very healthy snowpacks in useful places, seem much reduced this year. I'm of the impression that a pattern of weakly anomalous ridges surrounded by more anomalous troughs situated over the Arctic borderlands is about as detrimental as it gets for Arctic sea ice, as the air stays pretty mobile with only patchy cloud cover across the high Arctic, while there's a lot of poleward heat transport from the mid-latitudes that gets entrained into the anticyclonic circulation. As Neven rightly says on the ASI forum - we're lucky it's not May yet, but under clouds, some melt onset can occur at this time of year (as the dew point rises), of which satellite imagery shows some signs in the past week (patches of reduced-albedo ice from melt-freeze cycling).
  12. Broad suggestion emerging in the models of anomalously high Europe-Scandinavia heights taking over as the dominant theme for 2nd half April. A possible flip on the way, then, for the Atlantic side that’s benefitted from relatively low positive or some way negative anomalies for much of the time in recent months. GFS keeps tending to reverse the pattern developments past around D12, but that looks unreasonable to me unless the Nino base state totally fails to take hold. Admittedly, after last winters woes, I’m still wary of that possibility, but with the NINO region SST anomalies widely at their strongest now relative to the past 5 months, I’d be amazed not to see that base state properly establish itself this time around. The Nino base state combined with an increased propensity for high-latitude extent to ridges (via weakened polar jet) brings the potential for ‘pincer movements’ of anomalous heat, similar to of late but aligned Pacific-Atlantic more than Pacific-Greenland. How’s it Pacific both times you may wonder? Well, I’m of the impression that we’ve of late had a hybrid setup with the Nino forcing affecting the Pacific but not the Atlantic, due to interference from the exceptional HLB pattern that’s established following some perfectly-aligned wave breaks that seem untreated to ENSO. Possibly the extreme positive temp anomalies across much of the Arctic played a role in some way? Only as this ‘reactive’ HLB episode subsides does the Nino forcing become able to take hold across the Atlantic sector. Just a theory of mine, mind!
  13. For the sake of our wildlife, I'm glad to see the cold incursion being toned down for later next week. Looking beyond that, an increasingly strong suggestion from the models that ridges will start developing in the Iberian region and moving NE from there during the 2nd half of the month, as the atmosphere takes on a more typical El Nino configuration. They're just having a bit of trouble toning down the N. Atlantic westerlies enough; they should become pretty sluggish as AAM rises. So if you fancy seeing temps back into the 20s, you may only have a dozen or so days to wait, which given that we're in April isn't bad going actually (the late Feb spell distorts impressions).
  14. That second half projection fits an El Nino base state pretty well, except for a northward shift of the main positive height anomaly. The stubbornness of low heights S of the UK instead of them becoming focused across the Azores is unusual. I think it's a case of the anomalous HLB regime in response to some optimally-aligned wave breaking (as per the tweet above) contradicting the usual response during the first half, before it gives way and El Nino can make itself known. Or at least, that's how it should theoretically go. Signs of this from the GFS 12z today.
  15. We may be watching a tragedy unfold as the pattern adjusts in accordance to the El Nino background by weakening the polar jet and allowing the unusually expansive high-latitude blocking to spread across the UK, bringing light winds and clear skies, just as some notably cold air moves in from the northeast. That's a recipe for widespread minimums at least a few below zero, and potentially 5 or more below in quite a lot of valley locations. A lot of wildlife has sprung into action in the past month thanks to much kinder weather than last year brought but this, well, it could lead to widespread losses. The endangered bee populations are at risk for one thing. So as a fan of the natural world, I'm looking at these charts with horror instead (well okay, on top of...) of the usual awe. I'd have taken the 00z GFS' milder but wetter outcome over this, even after today's 12 mm and counting of rain here.
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