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Showing content with the highest reputation on 04/07/16 in all areas

  1. June has been an interesting month for many parts fo Western Europe, featuring excessive rainfall and floods for several parts of e.g. Germany, Switzerland and the Netherlands. This was caused by relative weak pressure differences over mainland Europe, on average rather low pressure and relatively moist air. However, July has shown a turnaround in the pattern. A steady westerly flow has brought a series of troughs and low pressure areas towards Europe, resulting in mostly changeable weather. Will this westerly flow persist, or will we see a significant change in the weather patterns to come? Westerly flow - but ridge to come The westerly flow has also been dominating today with low pressure to the north of the UK and high pressure to the south. However, change is on the way if we look upstream - just south of Greenland. GFS analysis of 500 hPa heights (colours) and surface pressure (white contours) for Sunday 12Z. To the south of Greenland, a weak ridge can be identified mainly in the upper levels (orange colours pointing northward). Often such high pressure areas (or ridges) tend to stabilize the weather for some time. - But for how long? The ridge will pass by the UK around this Wednesday, but it does not seem to be a rather transient feature. This fits very well in the pattern which we have observed over the past week or so - with ridges and troughs quickly alternating in a meandering westerly flow. GFS forecast of 500 hPa heights (colours) and surface pressure (white contours) for Wednesday 12Z. From the west a new low pressure area (green colours) is again approaching the UK. But will it also reach the UK? The models agree that this will somewhere around the weekend. However, one can also see notable differences developing between these models on the details of the low pressure area. (Un)certainty and phase differences The further outlook is what one could call certain as well as uncertain - depending on the point of view. Although there is a lot that can be said about the general pattern - it is about nigh impossible to have a certain local forecast in 6 days out or more! And we can caputure this (un)certainty in just one plot. GFS ensemble spaghetti forecast of 500 hPa height for Monday (8 days out) 12Z. The image above shows an ensemble of GFS forecasts for 8 days out. Here one should focus on the bottom lines, indicating the height of the so-called 5760 dam (5.76 km height) surface. Each line represents one model run. First of all, it can be seen that all lines are generally very close together for the 576 dam line, suggesting high certainty in the overall forecast. This forecast suggests low pressure to the north and high pressure to the south, with a potent westerly flow in between. One can also see this from all lines running west-east. See also the forecast of the CPC (Climate prediction center) for day 6-10. However, there is one huge caveat if one wants to apply this to a local weather forecast. If you examine all the lines individually, you can see that there are slight meanders in them. The position of these weak meanders (which can be interpreted as ridges if they point northward and troughs if they point southward) varies from run to run. However, the exact position of such a small scale feature is very important for the weather on that day. For example, a ridge for a given day (a northward pointing line) would argue for settled conditions, and a downward-pointing line would suggest a trough and thereby unsettled conditions. This uncertainty is what one could call phase differences, as depicted in the figure below. Illustration of phase differences between various model runs. Note how the location of the ridges (H) and troughs (L) differ strongly, an indication of a phase difference. Summary It appears that the westerly flow which has been present over the past few days will continue to persist for at least the next week (and probably thereafter). This will create changeable weather (with a possible drier interlude on tuesday-friday). Details at long range are hard to gauge due to the phase differences discussed above, but it is pretty certain that the main theme will be changeable weather.
    9 points
  2. That will truly be a day to cherish when knockers charts support high pressure..
    3 points
  3. Ironically I was (due to being on mobile) basing it on your summaries (generally unsettled) so assumed the anomaly charts must be showing negative height anomalies all the way south. Perhaps you were only talking about the longer term i.e. After Fri/Sat? Obviously I stand corrected on the anomalies. Although the ridge is pretty weak, the airmass is warm enough to raise the 500 mb heights above average.
    3 points
  4. This evenings ECM longer term isn't too bad. The continuing battle of HP to the south potentially building north and LP travelling east over the Atlantic towards Iceland. I'm hoping Knockers charts will support HP to the south pushing north from mid July. There's certainly potential for a settled spell. Just hopefully LP won't be pushed east but away Ne.
    2 points
  5. The GEFS 12z mean, longer term indicates the south has a good chance of being influenced by the Azores high (ridging) with spells of fine and warm weather and the met office update earlier mentioned something similar. There is also hope for the rest of the uk too from some of the 12z perturbations which show various anticyclonic scenarios from mid month onwards so although this summer so far could be politely called mixed, most of us could use stronger language to describe it....but hang in there. I remain hopeful that our luck will change before August!
    2 points
  6. usually means rain on the way, must have this time, wet now
    2 points
  7. Minimum today is 8.8 while maxima look like reaching the high 19s, so drop to 14.4C is possible on tomorrows update. After that, the 06z GFS has the CET at: 14.9C to the 5th (16.8: +0.4) 14.8C to the 6th (14.0: -2.3) 15.0C to the 7th (16.2: -0.1) 15.2C to the 8th (17.0: +0.4) 15.5C to the 9th (17.8: +1.5) 15.7C to the 10th (17.3: +0.7) 15.7C to the 11th (15.8: -0.9) 15.6C to the 12th (15.0: -1.5) 15.6C to the 13th (15.4: -1.2) Close to average conditions set to prevail overall for the next 10 days, with a CET in the mid 15s by the first 3rd of the month
    2 points
  8. Last chart of FI on the 00Z GFS showed exactly what I'm sure many would like to see at this time of year: Hoping for more runs to show an increasingly settled outlook into the second half of July. With this week also not looking too bad, more so further south, it would nice to continue to squeeze out anything autumnal/Atlantic-based.
    2 points
  9. Mainly cloudy today with the rain progressing east mainly confined to N.England, N.Ireland and southern Scotland. For the rest of the week (this morning's GFS) is pretty much a N/S split as a transient ridge brings some drier weather to the southern half of the UK mid week whilst the north is still subject to systems running NE from the Atlantic before more general wet weather arrives for the weekend. Temps varying around the mean but favouring the N/S split.
    2 points
  10. Some posts have disappeared again as off topic, And add nothing to discussion on what this threads intended for.
    2 points
  11. I'm not allowed to post much these days (work permits little), but I just wanted to point out that the 500mb anomaly charts are misleading for this week due to the fact that we have an unusually weak ridge of high pressure, which gives negative height anomalies in our vicinity yet still manages to prevent an unsettled regime across England until Fri or Sat. I'll leave you all to it now, have a good week
    2 points
  12. The ecm and NOAA still in the same ball park and indicate remaining unsettled for the next 14 days Of course there will be day to day variations on the smaller scale when the warm and colder air interact, or as Vorticity more correctly puts it the phase difference, within the long wave pattern as mentioned previously when discussing the general outlook. Thus a continuation of westerly upper flow with temps around average initially and then perhaps dropping a tad below.
    2 points
  13. The day I saw my first funnel from Peterborough a few years ago, on the way back I caught some what looked to be spiralling air through some residual cloud fairly low down. I've only ever seen that once and there wasnt any Cbs around at that time and it was pretty sunny too. The atmosphere seemed to be ripe for that so who knows, can't really confirm unless its caught on video really. Back to today, appreciate we're under a ridge today with no convective outlooks but just pointing out that mid west builds up some CAPE throughout the day with an upper trough arriving early evening. Mid level capping will probably inhibit any CAPE that is present. Midlands coverage and some more EA. MLCAPE slowing moving off to the east throughout the evening and night.
    1 point
  14. Cant complain with todays weather.. yesterday wasnt to bad either.. so 2 days out of 4 at the start of July have been acceptable.. lets hope the break down at the end of the week aint as bad has is appears.. If we can manage to get away witha decent first half of July.. The second half maybe warmer..
    1 point
  15. model discussion only please......other threads are available for discussion average temperatures etc
    1 point
  16. Average high here at the start of July is around 22.5c, the average for the month as a whole is 23.5c, and the average for the last week of July and first week of August is about 24.5c. Average highs of 70f/21c at any point in July or August is below average. 21c is the average for June, or the first third of September.
    1 point
  17. Reasonable week for those in the south and east, cloud fest for us in the north west with temps in the mid to high teens, woooopy do! And it wont even feel warm under cloudy skies. GFS0z offers hope long term but i'll not hold my breath. Can August buck the trend of the last god knows how many years?
    1 point
  18. 18c nighttime temp coupled with a modern house in my opinion is uncomfortable,in your opinion it's not,thats fair isn't it,everybody is entitled to their opinion. No idea what the heatstroke ref is about,makes no sense what so ever. Just because somebodies idea of being uncomfortable differs to yours is that a reason to go down the route of sarcastic remarks?
    1 point
  19. Ah I see! It was that smooth curved bit at the bottom that made me think it might have been a funnel but funnily enough I saw something similar a few years back which also turned out to be a scud. Thank you for the explanation! I'll get the real deal one day (hopefully)!
    1 point
  20. Looks like a very cheeky piece of scud to me. If the photos were taken over a period of 10 or more seconds I would definately say scud - that very bottom bit which curves doesn't evolve as it would if there were rotation. Also a cumulus cloud of that size wouldn't support the mechanics to produce a funnel, you would need at least a primitive updraught / downdraught system to get things moving. I've been fooled by scud a few times before - sometimes it really does mimic the real thing so well.
    1 point
  21. Temps close to 70f are below average! This area in July should be around 22-23c at average. I know we will hit that this week, but looking beyond it appears temperatures will be suppressed once more. Depressing!!
    1 point
  22. Been a lovely day today, which was good as it was Dover carnival day. Lot's of fun was had by the whole family.
    1 point
  23. It's not that bad, after the fine spell it looks like a return to sunshine and heavy, thundery showers with temps close to 70F. There is plenty of time for heatwaves yet, for all we know, August could be a sizzler chin up.
    1 point
  24. Enjoy this week if you get any sun, from the weekend onwards things are looking truly awful, massive high pressure covering the pole, with low pressure slapped across or near the UK. Can't really see any light at the end of the tunnel either!
    1 point
  25. The week ahead is going to become noticeably warmer according to the Ecm 12z with temps into the low to mid 20's celsius across the southern third / half of the UK during the second half of the week, especially southern / southeast England as warmer uppers (T850s) gradually spill across most of the BI from the southwest. The other good news is a ridge of high pressure builds across the south bringing largely dry and fine conditions for a while although central UK has a few rainy spells to deal with early in the week before conditions improve for Wed / Thurs. The fine spell lasts longest across the SE.The NW of the UK becomes more generally unsettled later in the week and eventually the fine spell breaks down further south, possibly with thundery rain / showers as it still looks warm and humid in the south of the uk towards the end of the week. Another ridge attempts to build into the south at the end of the week but the end of the run shows a trough slowly drifting east over the north of the UK so a cyclonic end with sunshine and heavy, thundery showers with temps closer to average but for the south in particular, most of the next 5 days or so look much better than recently, at least feeling like summer again!
    1 point
  26. Seems like a funnel to me too, various other examples online!
    1 point
  27. posts removed for being off topic....if you want to chit chat, use the pm system............I'm surprised posters in question didn't already know this
    1 point
  28. Looks funnel-like to me - but I'm no expert. You don't have to have a CB to have a funnel. Do you? William's comment just had to make me think of "clingons"!
    1 point
  29. A pleasant warm day spolit by everyone doing dyi at once. Max temp 19.1C now 18C, Barometer 1015mb rising, Wind F3 WNW, rainfall 0.2mm
    1 point
  30. I don't think knocker will ever be on my side, in winter he doesn't like cold and in summer he posts the coolest most unsettled charts he can find.. only joking malcolm.
    1 point
  31. Am I too late? If not 15.3C please.
    1 point
  32. Don't give up on a warm / very warm / hot spell developing during the second half of July. The Gefs 6z mean shows support for a warm spell as there are some peachy perturbations scattered throughout, a few hot spanish plumes too so don't give up..keep dreaming that this poor summer will dramatically improve before August! P18 anyone?
    1 point
  33. Wish I had done a little video of it now. It does seem quite smooth around the bottom in the second and third pics. Not saying I don't believe you though! You and the other folks know more about these than I do. Sorry if it seems like a silly ask. It's just not often that I see something like this. Plus, I've always wanted to get shots or video of a funnel cloud/tornado, so my wishful thinking probably made me think I had got something that wasn't there.
    1 point
  34. The Meto, no, but I do provide seasonal forecasts for a retail chain, that has a number of stores. I would agree, that if someone is consistently close, over a period of time, then that, imo, rules out guesswork
    1 point
  35. I won the seasonal competition in Spring 2013 going on hunches alone. Nowadays I tend to do really badly because I always go with my heart and punt for really low CET values (I'm normally in the lowest 5 guesses).
    1 point
  36. Evening Thunder's anomaly is insane. He must have been on for a record with them sort of figures.
    1 point
  37. 14.4c to the 2nd 0.9c below the 61 to 90 average 1.5c below the 81 to 10 average
    1 point
  38. Can we please only discuss what the 'Model Ouputs' are showing in here, 1000s of members expect to log in to this thread to read/learn on what the models are showing. There are threads open for general chit-chat and the likes above. Many Thanks, Please continue.
    1 point
  39. I won last year and will probably be into the top 5 after the latest results are up (was 7th overall after May, but got June spot on), but I can assure you there is little skill involved! Evening Thunder had an average error of just 0.16C for the first 5 months this year, but being a good sport, missed last month and had a few late entries to give the rest of us a chance!
    1 point
  40. would the transition from El Nino to La Nina be responsible for the change in the poition of the jet stream?
    1 point
  41. A decent week coming up with less in the way of rain and more in the way of warmth Next weekend doesn't look as good with GFS, GEM and ECM all agreeing on a deep low coming across the Atlantic what its exact track will be remains to be seen UKMO at t144 We may get lucky and see it track north of Scotland or knowing the UK's luck it will head straight for us... Not worrying on that much yet its nice to see a week of temps back in the low 20's and not mid teens!
    1 point
  42. Have you ever thought of working at the MetO im sure they would appreciate that level of accuracy. On another site theres somebody on an anomaly of 1.76 for the first 6 months! An average of under 0.3 error each month. That has to be more than guesswork!
    1 point
  43. Last year was the first time I played the comp properly, and finished 3rd, with the best accuracy score, this year, I will probably win it
    1 point
  44. Welldone on winning a year. I wondered about this. Might prove more is in this than just pure guesswork if similar people are usually at the top
    1 point
  45. Not sure, my attempts at a second title have proved futile
    1 point
  46. Has anyone ever won this CET competition twice(2 years) in all the years it's been running?
    1 point
  47. There's already a Summer thread so I'm going to lock this.
    1 point
  48. Are you feeling excited? I am... Is it too early? Probably Haha
    1 point
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