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Showing content with the highest reputation on 14/09/18 in all areas

  1. Met Office issue a warning that includes western parts of mainland UK and right on cue, GFS 06z adjusts furthest west of any run from that model so far. Serious hat on - the MO are right to include western UK as there's not only hurricane Helene but also subtropical storm Joyce consider as well when it comes to the track that this bout of unusually strong winds (for the time of year at least) will take. Longer-term, the signal for a notable build of high pressure from the southwest keeps turning up, but the details are varying a lot; With only a weak, stuttering tropical cycle to guide things, the knock-on effects of variations in tropical/subtropical cyclone movement are especially large, and it's hard to place much confidence in any particular solution, particularly given that the models keep seeing more of a tropical cycle emerging in the near-term than is actually observed; a persistent error that's been ongoing since mid-August.
    15 points
  2. ECM 192 >> 216 >>240 A very persistent theme being modelled for the past 48 hours with some form of atlantic ridge- very inlike last september - again indicitive of a weakened jet flow... Cmon- this is our year..
    6 points
  3. Irrespective of whether we get a warmer period towards the end of the month, I am still waiting to see how far east the track of storm Helene will get, and what strength the winds will be. This is what is currently showing for the 18th September: ECM UKMO GFS GEM Helene is confidently shown to be situated in the western approaches and this will be of interest to anyone contemplating a ferry trip to or from Ireland or northern France around this time. My bet is that there will be cancelled services. Anyone who lives in 'the west' is also bound to be interested in the maximum wind gusts over this period as the trees still have all their leaves and if there is a last minute change in direction further east and/or a strengthening of the overall wind speeds, disruption on land could also become a factor. I'm hoping that the storm will weaken, of course. Bring on that 'Indian Summer' instead......
    6 points
  4. My favorite "hurricane" video ever!
    5 points
  5. We would be screaming the place down if these charts was showing up in winter,pv displaced well west of Greenland
    4 points
  6. Following a generally warm first half, the second half of the Ecm 12z turns distinctly chilly and more autumnal with some cold nights, especially further north, cold enough for a touch of frost in places.
    4 points
  7. In the past, a parallel GFS has been the same model being trialled with an upgrade of some sort. Not so this time, it's actually a trial of a new model chosen to succeed the GFS called the FV3 (still presumably fed with GFS input data) - although it will still be called GFS if/when it takes over - the GFS is dead, long live the GFS! However, I suspect that the difference between models is a secondary uncertainty here, and the difference between the two runs is due to the actual significant uncertainty over the track of Helene, and over the intensity when and if it hits the UK.
    4 points
  8. Excellent illustration of the regional variation with this pattern
    4 points
  9. Back from a lovely holiday in Devon,just outside Honiton,looked up,saw 3 Red Kites,first sighting ever,nice end to proceedings.
    3 points
  10. Not too sure to be honest. I had a feeling back in February/March that last winter may have been the curtain raiser to a run of colder winters in the coming years, similar to how 2008/2009 was. The ECM seasonal run has certainly opened my eyes somewhat as I had largely written off this coming winter. I have read that next winter may see all of the large scale teleconnections align favourably so it's possible 2019/2020 winter may have a good run at that 62/63 style season? I've heard mumblings about the 2019/2020 winter for a few years now, so maybe there's something in it?
    3 points
  11. Some amazing images of Hurricane Florence https://twistedsifter.com/2018/09/hurricane-florence-from-space-hq-gallery/
    3 points
  12. Further to Singularity's excellent post above, the GFS 0.25 is showing this for 0200hrs 18th September: Max Wind Gusts: The storm is shown tracking just off the west coast of Ireland, albeit giving that coast a battering. However, the GFS 0.25 Parallel is showing this just six hours later: Average Wind Speeds: Max Wind Gusts: The latter 2 charts indicate sustained winds in my location at up to 70mph and gusts at or over 90mph. At this time of year, these conditions might be quite, if not very, disruptive. It is becoming important to know which of these two closely related models might be right, or if it's neither. Not being knowledgeable about the GFS, can anyone explain to me why the parallel model could vary so much from its older sibling?
    3 points
  13. No offence intended Newberryone but your saying ‘Indian Summer’ yet earlier today there were posts of ‘ low after low’.... whats changed or what makes tonight’s charts more reliable?
    3 points
  14. The south Irish Sea/west Wales is the favoured track for Helene with this evening's ecm which could give severe gales for a time in the south west and gales across south Wales and the Midlands with the Atlantic dominated by the upper trough.But there is bags of time for adjustments to be made.
    3 points
  15. another pleasant evening in superbia , was almost like a Californian evening with the beautiful golden light !
    2 points
  16. Looking at the Gfs 12z operational, there's very warm low to mid 20's celsius for a time next week further s / e and then a bit further ahead another summery spell for a time as high pressure builds in..nice☺
    2 points
  17. The difference between the GFS OP and GFS FV3 para is striking. Likely it's due to the different handling of the trough to the west, but treatment of convection with ex-Helene may be an issue as well. Here is the pressure of the PV (potential vorticity) =2 surface T120 VT 12 UTC 18Z September. The filament of PV extending from the large scale trough west and north of the UK and curving back to the Azores is key to the evolution of ex-Helene and is handled differently by FV3 along with the trough-ridge itself which appears sharper and less progressive in the OP run consistent with the weaker development. Unfortunately I couldn't retrieve MSLP from the Para file but it produces a much weaker system farther east. All the global models can struggle with trough extension- typically producing less sharp features than those verified, esp at T120. Therefore one should treat individual model solutions with a great deal of caution. However, on climatology grounds (comparing with Debbie (1961), Gordon (2006) and Ophelia (2017)) I would favour the western OP solution and this may not properly depict the intensity and trough interaction yet. David
    2 points
  18. The z500 geopotential anomaly charts are distorted by the fact that geopotential heights are proportional to temperature - with a warmer arctic there is a positive anomaly. Better to use sea level pressure - probably shows what many people want to see with regards near surface flow but the anomalies are not particularly dramatic - With regard to the stratosphere, it may have potential for wave 1 propagation from the eurasian side to the stratospheric Aleutian high giving strat vortex displacement. Just to add, looking at the earlier charts in the past year this completely missed the SSW influenced cold early spring and the warm summer.
    2 points
  19. Thanks Paul, it was from a coldie as I expected! As mb above has said, that run was an unsettled outlier.
    2 points
  20. Understatement of the year award goes to ........................ the storm is moving v slowly and the coast is not straight n/s or e/w .......... going to see some pretty awful videos over the next 36/48 hours ........
    2 points
  21. That’s one big hot ear
    2 points
  22. Overcast day today with occasional showers and a brisk W/SW wind. Max temperature of 15C. Also saw the first geese today, though just a mini-skein of about 20 individuals. Interesting to see them already as our resident house martins are still around - usually there is a gap between them leaving and the first geese being seen.
    2 points
  23. Strong sense of deja vu here as the POL was brought up in the discussion on the OPI back in 2014. At almost the same time the concept of the Taymyr Circulation Anomaly came to the fore in the paper October circulation precursors of the wintertime Arctic Oscillation (Kryjov 2014). This highlighted the correlation between Taymyr October geopotential anomalies and the following winter AO, but it seems the paper is still paywalled. At the time an arbitrary point was used to investigate this correlation (74.5°N 104°E) using 500hPa geopotential. However, the author co-wrote a follow-up paper Predictability of the wintertime Arctic Oscillation based on autumn circulation (Kryjov & Min 2016) which gives an insight to the earlier work and its application to forecasting (they use 700hPa geop. anom averaged and area weighted over 80-70°N 100-120°E). This paper is available - https://www.researchgate.net/profile/Vladimir_Kryjov/publication/292075140_Predictability_of_the_wintertime_Arctic_Oscillation_based_on_autumn_circulation/links/56c3f03708ae8a6fab5a3396/Predictability-of-the-wintertime-Arctic-Oscillation-based-on-autumn-circulation.pdf As illustrated in 2014, the homebrew Taymyr index proved superior to the POL in correlations with the AO, below are the correlations from 1950 up to last winter - Winter AO Dec AO Jan AO Feb AO Taymyr index 0.390 0.265 0.342 0.258 POL index 0.182 0.090 0.145 0.167 In particular it supports the link between October circulation and winter AO suggested by Kryjov. This doesn't tell the whole story however as shown in this chart of running 20-year correlations between the indices and winter AO. Also included are a Mongolian z500 anomaly (50°N 120°E) which has been used to create an estimated POL - The first few years are poor for all, this may be due to issues with data quality in the early reanalysis - the authors above use from 1958 onwards. After this though, the Taymyr index is better than the POL except for the 3 year period 2005-2007 (interestingly the artificial POL also beat the Taymyr), but more than this it proves to be relatively stable providing consistently good correlations over time. The same can't be said of the POL however which is poor in the early years even anticorrelated to winter AO and this is more strongly the case for the Mongolian anomaly - it would suggest that the value of the POL is given by the node in the area of the Taymyr circulation and it is dragged down by its dipole in Mongolia. In the second half of the period the Mongolian anomaly correlation improves which leads to better performance from the POL and there is also quite a marked sudden improvement for all including the Taymyr index. Couple of possibilities spring to mind - the timescales of Mongolian and POL correlations with winter AO are similar to the AMO. The 30 year correlation between the Mongolian anomaly and October AMO exceeds -0.7 when AMO leads by 29 years - but is >0.8 when AMO lags by 9 years (with over 0.95 for 10 year averaged AMO) - because of the timescales involved more data would be required to investigate this link further. The apparent sudden improvement in all indices may coincide with improved reanalysis with satellite data maybe. Finally with regards to changes since 2007, it is worth noting that all the correlations have fallen since the 2007-12 period.
    2 points
  24. *** ALERT - TODAY IS A DATE RECORD BREAKER FOR THE STRATOSPHERE *** Weakest vortex ever for 13th September @4.3M/S ( 0.2 m/s below the 2001 record of 4.5M/S ) data source ERA interim. Is this significant? - in isolation with a bandwith on todays date of 6M/S between the record strongest & weakest this its significance isnt as highly correlated to winter than say if we were here on November 13th- However today could be a signpost of whats to come this winter....
    2 points
  25. Atlantic ridge and possible N'ly becoming a recurrent theme.
    1 point
  26. high pressure still around, next month onwards if it settles in the right place then an early taste of winter could be on the cards
    1 point
  27. In America, it’s called fake wind, people,fake wind.
    1 point
  28. ,that is funny Has somebody got a blower at him.
    1 point
  29. The ecm is a cold outlier on the ens (London) ecm mean at 192-240 shows the Azures high influencing the weather from the SW esp the south and southeast of the uk the latest cpc 500 mb outlook reflects this 6-10 and 8-14 day anomoly's. http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php
    1 point
  30. Such a shame it is a beautiful historic town, hopefully they will recover soon
    1 point
  31. Are there any webcams or streams?
    1 point
  32. Travel sickness is the lest of my worries. I'm more concerned about the crash and burn option
    1 point
  33. I get bad travel sickness...mixed with anxiety, not a great recipe!
    1 point
  34. I wouldn't worry ,go arounds are exciting
    1 point
  35. Got a feeling a short early blast might be on offer early Oct, a lot of runs have looked favourable for teeing up a Northerly lately.
    1 point
  36. Some pretty impressive cloud structures today. Spent two hours fly down canyons SFC-8000ft. Tried to get above it but was hemmed not by controlled airspace. Photo was from down over Exmoor
    1 point
  37. I couldn't agree more! Unfortunately, US news always get priority and this includes natural disasters.
    1 point
  38. I was just thinking exactly the same !
    1 point
  39. Indeed Florence seems to have attracted most of the headlines however this Typhoon will be much more destructive in my opinion a truly immense storm.
    1 point
  40. Helene still looks strong to me when it hits the UK as an x tropical storm next week. The track currently shown by the National hurricane centre takes it right into western parts. Still one to watch closely !
    1 point
  41. Pretty easy one. That's when daily Arctic-wide measurements began with the type of passive microwave sensors that are still used today. it means we have a consistent record where each year can be compared to the next and so on. 1979 wasn't particularly unusual either. In fact, 3 of the 4 years after 1979 averaged a higher extent. You can try to compare previous data, such as in the images below, with the consistent modern record but it makes year to year comparisons less valid. It's only useful for stronger trends, especially as you go further back
    1 point
  42. 1 point
  43. The increasing AAM and GWO phase 3-4 move is a part of the equation, but also uncertain in terms of how far it goes. Generally I'm of the impression that the bigger the AAM climb, the further west Helene is likely to track as a result of the Atlantic trough being sharpened up. While waiting for the models to figure that out, I'm having some strong Ophelia flashbacks looking at this! Strangely, the rain distribution becomes more like a major hurricane as the storm reaches this point, having only resembled an 'angry blob' beforehand. Given what we saw last October, perhaps the increasing Coriolis effect while moving over unusually warm SSTs allows this gain in organisation and strength even as the SSTs lower. If it wasn't for what Ophelia did, I'd be throwing out any notion of a major hurricane making it so close to the UK. How times have changed!
    1 point
  44. No real evidence of an eye now as far as I can tell but there is deep convention in the south, which may lead to some re-organization. Many models taking just to the west of Ireland as a strong autumn storm. With no clear warm core most tropical characteristics will be lost although this could change (good chance of a little re-organization in my opinion) , but it will still be a significant storm for the Azores. There are a few outlier model solutions that take Helene over Cornwall as an Autumn Storm, but I think this is unlikely at the moment. The westward movement could be a little bit of a Fujiwarra effect from tropical storm Joyce. Some models show Joyce developing and following in behind Helene with a more eastwards movement heading eventually towards Portugal before dissipating. Looking at EUMetsat Satellite shots show Joyce not really developing in warm air and I don't really see it having a warm core. NHC seems to think Joyce can move into warmer air left from Helene and take on tropical characteristics. It is possible and it is even possible that Joyce could circulate back to off the coast of North Africa to reform. So I am not totally convinced by the westward movement suggested by the models and would not be surprised to see a little strengthening again of Helene based on convection in the southern quadrant. To summarize ,I have low confidence in the modelling , but don't expect hurricane like conditions for the UK. The prime risk is likely to be very heavy rainfall if at all based on current low confidence modelling.
    1 point
  45. It's that time of the year again when the jma pv chart gets into it's winter mode I would like to see something like this although i think it may happen a tad sooner,just a hunch.
    1 point
  46. Lovely sunset this evening (although my phone camera doesn’t do it justice)
    1 point
  47. 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.
    1 point
  48. Not necessarily, as it depends on where the cold air is being sourced from. Given some of the unprecedented temperature anomalies we've seen over the Arctic in recent years then perhaps cold spells from direct northerlies will be far less potent than they used to be, in which case "0.8°C less severe" may be an underestimate. However, we have seen some truly brutal cold-pooling over Siberia in recent years, which many believe could be a consequence of a warm Arctic (often referred to as "warm Arctic, cold continents"). So it may in fact be the case that we see Siberian-sourced cold spells increase in severity. The remarkably cold weather we witnessed in late February and early March of this year (upper-air temperatures briefly touching -17°C; you'd probably have to go back to 1987 to beat that!) perhaps demonstrates this. And what of cold sea-surface temperatures in the north Atlantic due to a weakening AMOC? If we see cooling in the right regions then maybe this could, to an extent, negate the effects of warmer Arctic air because the water over which the air is travelling becomes colder and hence we see less modulation? The same goes for cold-and-snow events off the back of Winter depressions: perhaps marginal events see more snow whereas previously we may have just had cold rain?
    1 point
  49. Important not to get weather and climate mixed up. I'd not consider an isolated one or two exceptional months to mean much, but here for example, my location has seen top 5% mean temperature months for each of April, May and June, followed by a record-hot July. That's beyond what can be reasonably explained by natural variability. Cold months, even record cold ones, will remain possible so long as snow falls across northern Asia and Scandinavia Nov-Mar, which thanks to the polar night, should always be the case. In fact, snowfall is likely to become deeper in those regions as a result of increased moisture availability from the warmer oceans. This could even lead to 3+ consecutive exceptionally cold winter/spring months one year soon... the warming global climate necessarily mean that the UK will share in that trend all year round.
    1 point
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