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Showing content with the highest reputation since 22/09/18 in all areas

  1. 39 points
    The above summer forecast verified reasonably well in most cases, the prediction implied a top ten outcome and in fact the summer was around 3rd to 5th warmest on record depending on which data you used. The CET predictions of 16, 18 and 17 compare with 16.1, 19.1 and 16.6 for an average error of 0.53 C deg, and it has to be kept in mind that August was running close to 17 until around the 23rd with a very cool finish. The overall prediction was closer, with an average error of only 0.27 C (17.0 vs actual of 17.27). It was a dry summer in many parts of southern Britain and southeast Ireland. The magnitude of this drought was probably underplayed in the forecast. As for North America, it certainly did turn into a scorcher of a summer in the west with widespread fires in western Canada in particular. We were dealing with noxious smoke on an epic scale for much of August (although I was away on holiday in clearer skies down south) and the first week of September before the activity finally subsided. The tropical season has not been keeping pace with the forecast although it could still work out fairly close, and Michael alone is worth several ordinary hurricanes I suppose. ... well, I won't make a big deal about this forecast because basically I think almost everyone expected this sort of summer after the spring blocking, so it is now on to the winter of 2018-19 for the next instalment ... Long-Range Outlook for Winter 2018-19 As always, my forecast is based on a blend of traditional concepts and exclusive research into "index values" on the assumption that at least some variability in the climate can be linked to variations in the solar system magnetic field (a complex response to relatively small changes in solar wind output and effects on the earth's linked atmosphere and magnetosphere). It is looking quite cold compared to normal for Britain and Ireland, in particular later December and parts of January. However, this appears to be dependent on a strong jet stream either shifting far enough south or relaxing for periods of 1-2 weeks, and the intervals between the cold spells could be quite stormy at times when the jet stream is roaring at full capacity. The research index values in particular go far colder than I have seen them for the past several winters, indicating many analogue cases that were very cold winters. Looking through the analogues, I find that periods around late December into early January, and mid to late January, were favoured for the coldest weather. This is also favoured by assumptions made about lunar modulation of the pattern, which is how I have come to see the lunar influence, not as a driver so much as a shaper of larger signals from the other players at work. Another consideration is that we are well into a prolonged solar downturn and so there's nothing in the larger solar-weather paradigm to contradict the notion of this being a colder than average winter. We are in a similar position to the period 1819 to 1823 which had numerous cold winters but it's not a guarantee by itself to be in this sort of regime. I've seen some discussion saying that perhaps this won't be the widely expected "big one" and perhaps we'll need to wait another winter or two, but I have no way of choosing which one is the big one from the coarse assumptions that one is forced to make using only a solar-weather paradigm. The past summer season in the central Canadian arctic was exceptionally cold. Resolute for example had no month warmer than the 1.9 average in July, and that is the lowest such statistic on record in recent times (the record began in 1948). This has been followed up by a large-scale southward movement of a cold anomaly over central Canada that has people commenting that winter already began in the prairies in early September, with snow often on the ground. This anomaly is almost bound to be followed up by a persistent trough around 90 to 100 W longitude. That in turn would favour west Atlantic blocking and a downstream trough between 10 and 30 W. Although that's a little west of the "sweet spot" for a cold winter in Britain and Ireland, I feel that it may be a high amplitude pattern that will induce Scandinavian blocking highs, and cold outflow from those despite fairly high 500-mb heights in western Europe at times. And the pattern could oscillate east-west enough to place the trough over Britain and Ireland at times. So I am predicting a notably cold winter but with high variability possible leading to alternating spells of wintry cold and stormy fast flow situations. Another factor that may prove significant is that energy levels will be highly concentrated near the full and new moons this winter, perhaps more so than has been the case in most recent winters. I expect this to translate into alternating periods of very unsettled, stormy weather around those lunar dates, and relatively long settled intervals between them. The settled intervals are likely to be the times when blocking will deliver the colder air masses from an easterly or northeasterly source. But there may be some tendency for the disturbed intervals to remain cold and turn more northerly. This could add up to considerably more snowfall in the heart of winter than we've seen for quite a few seasons, in contrast to last winter's concentration of snowfall near the very end of the winter season (27 Feb to 2 March was very snowy in some regions). I am aware that this represents a high risk forecast, especially given the tendency of recent winters to resist opportunities to establish potent blocking. So it won't absolutely surprise me if the result is some kind of weaker compromise where some cold and some snowfall develop but longer intervals remain relatively mild. I don't foresee a really mild winter being likely given these background conditions, and I do have concerns that the volatility may produce some exceptionally stormy intervals. This pattern may persist well into late winter and March may not see a lot of change from it, except that by then the energy level considerations will be more evenly distributed into four peaks rather than two per lunation. That separation during February may lead to a peak in snowfall since the peaks will be somewhat less supported and that could be reflected in a more persistent blocking pattern. As to the dates of the stormy episodes, those appear most likely to fall around 19-22 December, 3-6 January, and 16-20 January, and there could be heavy rainfalls in the south during some of those intervals as colder regimes are pushed back to the north at least temporarily, but as time goes on the chances for snowstorms likely increases with each of these windows, then towards the end of January it may be more of a sea-effect snowfall opportunity with the storm track pushed much further south into Iberia and the Mediterranean. During the anticyclonic intervals that are likely to peak between those stormy intervals, we could see some unusually low temperatures especially if snow cover has been established towards the transition from stormy to settled weather. In the run up to the winter, I would expect quite frequent mild and unsettled patterns with the colder synoptics taking their time to appear, possibly in muted form around mid to late November so that perhaps Scotland will get the first round of this predicted wintry regime. In North America, I am expecting a winter dominated by intense cold over central regions, often extending out to both coasts, and a generally depressed jet stream but with weak El Nino tendencies likely to lead to frequent and heavy snowfall inland from the west coast over the Rockies about as far south as northern New Mexico. Parts of eastern Canada may be unusually mild with the storm track tending to run north from near Cape Cod into eastern Quebec province. I feel like this may be a very rough sketch of a winter that may contain some really unusual synoptics and bring conditions that are rarely seen at some times, and those are difficult to anticipate so would just caution that various extremes may be tested at times. I don't think it will be a dull or boring weather pattern for most of the winter, in any case. For verification, I expect the average temperatures to run as much as 1.5 to 2 degrees below recent normals and for this winter to be one of the colder ones in the past thirty or even fifty, and colder even than the longer-term averages which run almost a degree below modern 30-year averages. I somehow doubt that it could be an all-time cold contender to match the summer because that seems to be very difficult to achieve with the ice margins being as far north as they have set up in the North Atlantic in modern times. But as we saw in December 2010, anything is still possible and there could be some intervals of record breaking cold.
  2. 32 points
    Just for fun at this stage but the CFS looks interesting for Boxing day Even -16c uppers a few days later! 1962 anyone?
  3. 26 points
    The cooling trend has begun!.. And certainly some interesting anoms/features begining to raise as we walk slowly into the new season. The format feels somewhat like a jigsaw with missing parts that are starting to be found. And solar activity 'im sure will have a climatalogical impact....this quickly coming winter. And the dice ....i hope will roll a 6...for our shores. An iberian/baltic sea heat spike...and a cooling and a rapid cooling around the arm of northern most scandinavia...is a characteristic fond to the eye...at this stage and for priming the desired blocking formats.....its good 2 b bk!!!. #winter 2018/19......
  4. 21 points
    Certainly no October Bore fest over in Calgary last night. 20 -30cm fresh snowfall. A different climate in the Prairies !
  5. 21 points
    Nov - March - Blocking, cold to very cold and snow. I'll take that
  6. 20 points
    Sorry mate but that's complete nonsense. I can tell you that people can and do make a lot of money from LRFs! Anyway, I'm giving a presentation tomorrow on a winter forecast so here goes. Front-ended cold winter with a largely blocked pattern through December and January, mild more likely going into Feb. Negative QBO is transitioning into a positive one through winter which isn't good for cold, but we are now at the very bottom of the solar cycle which plays very much into our favour for a colder winter. ECMWF seasonal* supports this, but then again the UKMO and CFS do not... *EC seasonal has consistently had a very easterly themed December!
  7. 20 points
    That would be a shock to the system. This year seems to have been one of extremes, instead of the usual gradual switch of seasons, we've jumped from one straight into the other. Just imagine if the summer on steroids we've had is matched equally by winter.
  8. 19 points
    So an early look at my LRF for winter 2018/19. Before I go into it I want to say I believe a winter to rival a 20th century great will occur within the next 3 winters. Let’s start with why I believe this. Following taken from Spaceweather in relation to sunspot count. 2018 total: 165 days (58%) 2017 total: 104 days (28%) 2016 total: 32 days (9%) 2015 total: 0 days (0%) 2014 total: 1 day (<1%) 2013 total: 0 days (0%) 2012 total: 0 days (0%) 2011 total: 2 days (<1%) 2010 total: 51 days (14%) 2009 total: 260 days (71%) 2008 total: 268 days (73%) 2007 total: 152 days (42%) 2006 total: 70 days (19%) I compare 2018 to 2007 = 11 year cycle going forward. We know the winter 09/10. Potentially we could get an 07/08type winter...but I think we are past that as one can see we have still got 2 1/2 months to go and we are 13 more spotless days already....I think 190 but 200 is not insurmountable. I am also not of opinion of Gavsvid updates that this year ‘could’ be solar minima. 19/20 imo more like it. And if it continues as last minima.....moving on from this year we could be in territory not seen for over 200 years. (Interesting RJS mentions 1819/22) El Niño (weak?) so not unfavourable Will the cold Atlantic to our West be of relevance? As already posted as snippets I think winter starts early. So overall theme I feel prevalence of northern blocking with Scandi Blocking likely to be a player with at times an active jet bringing in LP systems but ultimately failing to upset the rhythm of winter. December - colder than average. I won’t put too much meat on bones yet but after a wintry first half I suspect blocking to be in place approaching Xmas and then an Atlantic trying to push in against a cold block that won’t give way (period of note possible). I say it won’t give way as I anticipate January to continue with the colder than average winter. January - colder than average - 1st 10 days earmarked for potential coldest temps of winter with cold block established over (if anticipated) snowfields are widespread. I think mid and backend of January to be potentially very snowy with LPs attempting to take over the ‘general’ pattern as I think the blocking will be at it’s most vulnerable as we enter February February - Average overall but wet. I think the rhythm eases somewhat and we could see winter wane. There is a possibility that jetstream holds on southerly track and wintry conditions elongate but Atlantic vulnerability I’ll call it. A winter to match a 20th century great over next 3 winters?...means I am saying it could be this one. For sure imo we have entered a period going forward where we could be in the game for some serious synoptic patterns. Serious cold and long is still very achievable and imo going to become ever more achievable. As always, with blocking if in wrong place then is a blow out......and Greece etc are locked into an ice age and we are distinctly average, bland even a touch mild....but better to have prevalent northern blocking to put us in the game for cold. I’ll add more with what I identify as ‘periods of potential most impact’ in Nov..... BFTP
  9. 19 points
    This is the sort of pattern I envisage setting up and repeating all winter.
  10. 18 points
    Let's hope the Gfs is right about an Arctic blast at the end of October and then it will be Hats on..and scarf..and gloves!
  11. 17 points
    Indeed Frosty whilst I understand some enthusiasm from those looking at blocked Winter CFS charts that is a nice October set up for an Indian Summer. The real indication for vortex development will come towards December when zonal winds tend to really increase. I am quite happy to see that continental high wafting warm southerlies over us for another month until we have a better chance of Winter weather.
  12. 16 points
    The OPI had a lot of attention but didn’t amount to much . And crashed and burned when it promised a colder winter which never materialized . As everyone knows who follows these forums in winter anything that suggests a colder winter and doesn’t deliver is dispatched to the outer corners of the universe!
  13. 16 points
    Looking at the Ecm 12z, high pressure gets pushed and pulled this way and that and we get a cold crisp start to October which would feel quite wintry, especially further n / e...winter is coming!
  14. 16 points
    Slight differences with the ECM tonight the high pulling out further west allowing colder 850s in from the north . Surely I'm not gonna get accused of spamming this thread up with this post am I ?
  15. 14 points
    Came on here just to say, it really is a beautiful day I know there's clouds, it's cool, it's grey But for me, it is a beautiful day You're strangers all, but kind of not So I've got to share the news I've got Right now in my baby's arms does lay A bouncing boy, born this day A brand new grandson, oh lucky me Forgive me all for sharing my glee!
  16. 14 points
    Morning all, had an interest chat this morning with our portal forecaster about the possible deep cyclone that could develop next weekend in the vicinity of Southern Britain. Feeling are that the situation becomes quite fluid in 5 days time as the Eastern Atlantic trough moves into NW Europe. A baroclinic zone becomes established towards the North Sea, not surprising really when you see the 144t 850mb forecast temperature chart below. Very cold air getting established to the North and meeting pulses of warm air moving poleward through Eastern Europe, hence the North Sea could see fairly rapid cyclonic development. However, at this stage the positioning , deepening and potential cut off low formation is still showing a degree of uncertainty but defo one to watch. Their own model tends to show a bit more of a southward positioning and could change very quickly over the coming days. We have a snow alert for tonight, not a lot but fine mesh model predicting 5 cm in the village as the freezing level gets down to 1750m tomorrow morning.
  17. 13 points
    Another Gfs run showing an Arctic blast with snow, ice and frosts towards the end of october..hope the 00z is right!!..Great model watching!
  18. 13 points
    No, no, no, absolutely not. I'm in no way ready, or even vaguely willing to accept the possibility that I'm going to be cold and wet all day in the near future. The whole lot can clear off, southerly weather can continue for at least another 4 weeks, preferably longer. Cold can come the week before Christmas, at the earliest.
  19. 13 points
    For those who never saw it watch this .. gets 'interesting' around 30-34 mins in !
  20. 13 points
    Well if people want a cold start to winter, the charts showing today (i'm looking specifically at the 12z and 18z GFS) are pretty on point. Huge blocking to the E and NE which is enabling the trop vortex to remain perturbed. The next thing we'd want to see after this is some pressure from the Canadian vortex pushing a trough ESE across the Atlantic, this troughing not making it much further E than the meridian (with HP remaining to the ENE). Once we get to this point, we're in November 2009 territory... Can we get there, that's the question? However, the modelling is looking very closely aligned to EC seasonal thus far...
  21. 13 points
    Looking at the Gfs 12z operational, the generally uk based anticyclone is under sustained attack and gets pushed and pulled around a lot more than the 6z..and then it turns colder and very unsettled with a Northerly blast which is set up for further reloads beyond the end of the run..even some snow for the hills / mountains of scotland and quite a wintry feel to early october on this run! ❄
  22. 13 points
    Using the anomaly charts this is what I wrote in my daily summation this morning. Only ec shows any signal for troughing into Europe; all 3 show the main trough is way back, the Canadian main trough in fact. More settled more often for areas well south, less so the further nw one lives and probably mostly changeable covers it for the nw’ern areas of the uk. Ec-gfs and ec not that different to the one above, less pronounced ridging though, gfs about the same perhaps? Noaa and its ridge is less pronounced although the +ve signal looks very similar if slightly further w than that above. links http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php Just one line of psters showing probably sums up how quickly any changes are likely. No sign of an Indian Summer yet and no real signal for anything other than slight frosts under clear skies for the cold watchers.
  23. 12 points
    glorious morning across Esher Common !! autumn is well and truly in full swing ..
  24. 12 points
    So Summer came, we had a blast Hot day after day, but it's fading fast Not sure I'm ready to say 'Goodbye' To summer warmth, sun high in the sky There's a bit of a nip in the air just now Summer has gone, it's taken a bow Autumn's come, not slowly drifted in Pushed summer aside, come making a din The wind and the rain, rattling through Reminding us all, trees and fences he'll slew Oh please be gentle, be kind, be mellow Leaves of gold and conkers, you can be a fabulous fellow I want time to savour the slow fading Of roses and trees, remember their shading When I hid from the heat of the summer just past What a wonder it was, we had a blast There's a time and a place for all in life Weather's no different, but I expect strife When I make a plea, don't pray for snow Let autumn play, don't skip it or let it go There's beauty a plenty and joy to be had Don't wish it away, winter can wait a tad You regulars sigh, must fill you with dread When we migrants descend, invade this thread But remember the joy of the first summer swallow We're the opposite end as we drift in to follow Every model and forecast, hoping for snow But for me, for now, I don't want summer to go
  25. 12 points
    After that im talking about, looks primed for a N'ly, im still waiting for that much vaunted continuation of the early summer that's been talked about on here since early August, its been about 12c here recently and Essex is progged to have an airfrost early next week.
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