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stodge

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  1. The 6Z Control has a very strong signal for blocking in low-res. Indeed, the evolution would, if occurring in early January, have this forum in meltdown: A fine example of a retrogressing HP but of course no likelihood of verification. The GEFS, as James suggests and I alluded to earlier, is signalling strong HP for the second May Bank Holiday weekend but the majority of the Members show the HP centred to the north or north east of the British Isles so an E'ly or even NE'ly flow so it's hard to see any temperature records being broken this time and it may be eastern coasts will struggle with sea fog and haar but for most and especially the further west and northwest you are, it looks fine and settled. Let's see how this plays over the next week or so.
  2. Morning all A notch cooler in London this morning but still pleasant enough after the overnight rain. The models were offering two very different evolutions yesterday so let's see where we are today. The medium term analysis takes us to Sunday May 20th and starts as always with the ECM 00Z at T+240: ECM not too different from yesterday. The weekend's disrupting LP fires some energy into Europe re-invigorating the trough over the continent but attempts to build HP back in are pushed south as northern blocking based over Greenland starts pushing the jet back south and the LP systems off the Atlantic start coming on a more southerly track. At T+240 the Azores HP is suppressed far to the south and the LP is moving west to east across Scotland with a second LP set to follow a similar if not slightly more southerly track. It's unsettled with rain or showers for all and quite cool especially in the north. GEM 00Z at the same time: Very different. The blocking over Greenland is much less influential while the Azores HP is much more influential sending a ridge NE to the south of the British Isles. The Atlantic LP is further north and positively tilted so we have a benign SW'ly flow for most with fine conditions for southern and eastern parts though more unsettled in the north west. Signs of the Atlantic trough digging south so we could see a spike of heat from Iberia for the second May Bank Holiday. GFS 00Z OP at the same time: A slow moving and slack evolution which ends up quite messy. As I said yesterday, you have two competing pressure patterns at work. To the west of the British Isles, we have the classic LP to the north west and HP to the south west (though the latter is very shallow on this output). To the east, heights over Scandinavia are balanced by LP over southern Europe originating from North Africa. The British Isles ends up in the col between these competing pressure systems so decent conditions particularly for the south and east but more unsettled further north and west where the Atlantic influence is most noticeable. Further into FI pressure builds through the British Isles from the Azores to Scandinavia keeping most fine but LP remains over Europe and for the south east there would be a light NE'ly and the risk of a shower (more so for the Channel Islands). GFS 00Z Control at T+240: Pretty close to GEM with the Azores ridge holding off the Atlantic LP which is quite vigorous for the time of year. Further into FI HP remains mostly in charge but at the very end of FI, as the HP weakens, the European LP starts to take control with a new LP extending NW across southern Britain suggesting thundery outbreaks. Welcome back to the GFS Parallel run and I'll be featuring this rather than the Control from now on and here's the 00Z at T+240: More of an Atlantic influence with the trough looking to sink SE and join with the trough over Europe. Further into FI it's a see-saw between the troughs to the NW and SE and the HP to the SW and NE. The latter wins out at the very end of FI on this run. The 00Z GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 As we've seen, the "struggle" between the competing troughs and ridges continues but on this evidence the ridges are coming out on top with a majority of members looking to maintain HP close to or over the British Isles. Moving on toward the second May Bank Holiday and the signal for settled weather is very strong from the 00z. Whether the HP is in the right position or oriented to draw up the warmest air isn't clear but a majority of the members look warm to hot. In summary, May is often a curious month with unusual synoptic patterns and sharp contrasts in temperature and weather. With the Atlantic often at its weakest, the influence of the Scandinavian HP and European trough are often felt more strongly now than at other times. Northern blocking is for the second day running a strong part of the ECM scenario while GEM is more anticyclonic and positive and GFS messy and uncertain. In truth, little change from yesterday. Moving toward the last third of May, the possibility of unsettled conditions affecting the south east in particular from Europe remains but the signal for a dry and settled Bank Holiday has grown this morning and it may be that after the stampede for the sunshine last Monday we may see a repeat performance but it's far too early to be certain.
  3. Afternoon all :) Unfortunately, the daily update running slightly behind schedule but no matter. A cooler but still very pleasant day here in London Town but a sense perhaps of a change back to something more typical for mid May than the current July-like conditions. On to the models and the medium term analysis to Saturday May 19th: ECM 00Z at T+240: http://www.meteociel.fr/modeles/ecmwf/runs/2018050900/ECM1-240.GIF?09-12 On the face of it, not too bad with a ridge of HP covering most of the British Isles. ECM has the weekend LP disrupt and fill over Ireland but the key development is the return of strong northern blocking as a large 1045MB HP sets up over eastern Greenland. The jet is moving back south in the face of this and Atlantic LP systems are going to be moving through the British Isles which means more rain and wind for most. GEM 00Z at the same time: http://modeles.meteociel.fr/modeles/gem/runs/2018050900/gem-0-240.png?00 GEM was the most anticyclonic of the models yesterday but today has come more into line with ECM. After the weekend LP disrupts and fills a new LP develops over Scotland briefly but that too fills in the face of rising pressure from the north and east. As the ridge builds in from the east, the Atlantic LP stalls in situ so a warm and largely settled outlook for most with only the far west of Ireland seeing drizzle. GFS 00Z OP at the same time: http://modeles.meteociel.fr/modeles/gfs/archives/2018050900/gfs-0-240.png?0 A very soggy and unpleasant chart especially for the south with rain, possibly heavy at times, for southern parts. It's quite a messy evolution this morning from the American model and not really in sync with ECM/GEM. After the weekend's LP fills, there's an attempt to raise pressure from the SW but by Tuesday next week a new LP is developing to the NW and squeezing out the heights. Meanwhile, pressure is rising strongly to the far NE and all that does is push the complex trough down across the British isles by the end of the week. Further into FI and the British Isles essentially is in the col between two competing pressure regimes. To the west, we have the traditional LP to the north and HP to the south but to the East we see HP over Scandinavia and LP over Europe so you'd think the Atlantic trough could drop SE through the British Isles or the HP could ridge NE but in essence neither happens. GFS 06Z OP at T+234: http://modeles.meteociel.fr/modeles/gfs/runs/2018050906/gfs-0-234.png?6 Variation on a theme albeit with the small LP about 700 miles further north. Further in to FI and it's a pattern we often see at this time of year as thundery LP heads north from Africa and Iberia toward southern Britain forcing the Azores ridge NE over northern Britain and we end with a warm and dry E'ly albeit with a hint of thunder for the Channel Islands. GEFS 06Z at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 The spread to the NW tells the story between those members who favour a continued Atlantic dominance of our weather and those who look at northern blocking and a more continental influence. The OP went with the latter but the Mean plays the col card which isn't unsupported either. Further on and it's the same old story of the strong signal for northern blocking so we'll see. In conclusion, the pattern through to the weekend and beyond looks set. GFS has quite a messy evolution which doesn't end well for the south while both GEM and especially ECM bring in strong northern blocking which pushes the jet back south. It's far from a washout but with LP systems tending to move across the British Isles rather than to the north we would get quite unsettled and wet spells. There are also hints of low heights from the south coming north which isn't unknown at this time of year and can bring thundery downpours but that's looking more toward the last third of the month and wouldn't be unusual.
  4. Morning all A glorious early summer spell continuing for many into a fourth day with the highest temperature values of near 29c to the west of London. Clear signs of a moderation in temperature this week but into mid month there were, last week, notable hints of renewed northern blocking. This morning's medium term analysis takes us to Friday May 18th and starts as always with ECM 00Z at T+240: It's an interesting evolution. LP approaches from the NW through the coming weekend but disrupts in situ. However, as HP tries to build in from the west, LP over Europe re-asserts and by T+240 a shallow LP centred over western Britain controls the weather so the forecast would be showers or longer spells of rain possibly thundery developing across southern and south western areas in particular. The Azores HP is ridging to the NW of the British isles and the trough remains over continental Europe. GEM 00Z at the same time: GEM keeps the weather fine and settled for many for the foreseeable. The Atlantic incursion over the coming weekend amounts to very little and is pushed back NW allowing the Azores HP to build across the British Isles and by T+240 a large HP cell covers the British Isles with light if not calm winds and plenty of fine weather. A deep LP looks becalmed far out in the Atlantic and all that does is prop up the HP. GFS OP 00Z at T+240: Another very interesting evolution, closer to ECM than GEM in all honesty. The weekend LP tries to disrupt SE through northern parts of the British Isles but a renewed push of heights from the Azores HP keeps southern areas reasonably settled. However, early next week the heights start to recede as LP becomes more organised first to the north and north west before sinking SE through the British Isles and linking with the trough coming north from Africa and southern Europe. The Azores HP ridges more north toward renewed heights over Greenland and to the north of Scandinavia. At T+240 there is a brisk N'ly over western areas but eastern areas are under much lighter winds but with rain or showers developing over the British Isles and especially for eastern parts. Further into FI we get 36-48 hours of unpleasant cool and wet conditions from a small LP in the southern North Sea before the trough transfers NW back into the Atlantic and heights build in again from the SW. GFS Control 00Z at T+240: Cool and unsettled with the LP sinking south toward the British Isles. Further into FI the trough remains close to the south and east while heights build to the north and west leaving winds in the easterly quadrant and a greater risk of rain or showers for southern and eastern areas. The 00Z GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 Two main clusters on offer - one has the Azores HP building strongly in from the SW and the other doesn't meaning LP over or close to the British Isles so, if you like, the GEM evolution versus the ECM solution. Further into FI and the signal for northern blocking remains with only two or three members keeping the Atlantic as the dominant force. The northern blocking varies in position and orientation considerably. In summary, two possible evolutions into medium term this morning. The GEM evolution keeps the weather settled with the Azores HP ridge taking over once the weekend's Atlantic incursion disrupts and retreats NW. The ECM/GFS OP solution is messier and brings low heights over Europe into play with enough energy phasing from the disrupting Atlantic trough to invigorate the trough over Europe which spreads north. The question then is one of energy transfer - with GEM there is no transfer of energy and the anticyclonic ridge builds back through the British Isles but with ECM and GFS enough energy spills SE across the British Isles to re-invigorate the European trough and send it north. Which model is correct or are both wrong ? As ever, more runs are needed.
  5. Morning all With a decent weekend heaving into view, how are we looking as the weekend after that approaches ? When I last looked a couple of days ago, there were plenty of hints the anticyclonic spell might break down to something more unsettled so let's move ahead to Sunday May 13th starting as always with the ECM 00Z at T+240: A decent evolution for many from ECM with the weekend's cell of HP easing east to be replaced by another midweek which in turn moves over Scandinavia. The T+240 char tis a little messy but with the jet held well to the north you'd think settled conditions would dominate especially for southern and central parts. A shallow area of LP to the west of Scotland doesn't look to be doing anything much at this time with the large Azores HP dominating to the west. Over Europe low heights have been pushed well to the south and south east. GEM 00Z at the same time: A much more unsettled evolution from a model which has previously played the anticyclonic card very strongly. The weekend HP eases to the east by Wednesday but there is no second cell as per ECM. Instead, a much more active Atlantic brings LP and frontal systems toward the British Isles. The feature to the north of Scotland is in fact a secondary LP which swung NE across Ireland being gales and heavy rain to western parts. The forecast would be rain or showers for all with the heaviest rain in the north. Hint of a brief ridge coming through before further LP systems move in off the Atlantic. GFS 00Z OP at the same time: Again, more unsettled. As per GEM, an active LP sweeps in from the Atlantic passing to the NW of Scotland and by T+240 is easing away NE with a residual trough over northern parts while there are signs of pressure rising further south. Further into FI and an unusual evolution as LP develops over central Europe and moves WNW across the British Isles so a potentially cool and quite wet spell of weather around mid month. GFS 00Z Control at the same time: The evolution in Control is similar to the OP if a shade more progressive. The deep LP moves away more quickly to the north and fills leaving a small trough over northern parts. Another curious evolution further into FI - pressure rises over Scandinavia and falls over Europe and a small but active LP moves west across southern Britain leaving all parts in a warm SE'ly. The GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 The Mean suggests encroaching LP from the NW and there are only a couple of GFS members with anything like an ECM evolution so suggests that may be a shade of an outlier. Most have LP passing to the north of the British Isles but two or three hint at disruption SE across the British Isles and into Europe so possibly one to watch. Further on and there's plenty of northern blocking but we've seen it before in high-res and it rarely comes through to low-res so at this stage I'd say the signal past mid-month is there is no strong signal at this time. In summary, a fine spell through this weekend and into the middle of last week looks unlikely to continue much further. ECM tries to continue it but looks isolated as both GEM and GFS bring in more unsettled conditions off the Atlantic. GFS explores some synoptically unusual solutions further into FI but that's a long way off.
  6. Morning all After yesterday's winter-like day in lowland East London, we start a new month with a considerable improvement - the Sun out and the temperatures on the up. The weekend ahead looks set fair which will please many but where do we go from there ? Plenty of possibilities yesterday and let's move to the end of next week, Friday May 11th, for this morning's medium term model analysis Starting as always with the ECM 00Z OP for T+240: Reminiscent of yesterday's 00Z GFS OP - the first HP for the weekend declines but new heights build to the north and north east of the British isles so by T+240 it's generally settled but with a cool NE'ly breeze across southern parts. The next LP is negatively tilted and it would be fascinating to see if it would dive SE to the west of Ireland (as GFS OP did yesterday).. On then to GEM 00Z at the same time: GEM was very anticyclonic yesterday and remains so today but as yesterday a hint of change at the end of the run and as yesterday it's worth looking south as the trough develops over France and, combined with falling heights to the west, my view would be the warm settled outlook would degrade to showers and something much less settled. Let's see if the trend continues through tomorrow. GFS 00Z OP at T+240: An increasingly unsettled outlook as LP has moved down from the west of Iceland to be just off North West Scotland with frontal bands crossing the country albeit with only light rain for the south east. Further into FI and the unsettled picture continues with LP close to the north-west of much of the run. GFS 00Z Control at the same time: Not a million miles from the OP but with a more intense LP close to western Britain so rain and strong winds for Ireland. Further into FI and the LP disrupts to the north west as heights build again to the north as was a feature of 00Z low-res yesterday. The 00Z GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 While the OP and Control scenarios aren't without support in the suite the majority call is to retain the anticyclonic domination with HP close to or to the north east of the British Isles more aligned to the ECM solution. Further into FI and the strong signal for northern blocking remains undiminished with HP close to or to the north of the British Isles across the ensemble members. In summary, fine weather for the Bank Holiday and continuing through next week on the models but a hint of a change at the end of next week with LP encroaching from the NW or south and heights falling to the west suggesting a more thundery and wet outlook for many. This looks short-lived for the north with HP returning by mid month but the south remains potentially warm and unsettled with the risk of thundery showers or rain. Today's bonus chart comes from T+5736: Fine and frosty for the British Isles with, as usual, the coldest air just missing us and a white Christmas for the south of France.
  7. Morning all A pretty disappointing start to the week here in lowland East London with rain and a cold wind but change is the only constant when it comes to our weather and it's looked likely for some time the first May Bank Holiday Weekend will be decent but what happens from there. Today the medium term analysis takes us to Thursday May 10th and starts with the ECM 00Z at T+240: The fine spell over the BH weekend breaks down next week as the HP declines far enough east to open the door to the trough and more than a hint from this chart that the LP could slip SE into Europe and change things considerably. For now, a gradual cooling with rain or showers encroaching from the north west. GEM 00Z at the same time: Anticyclonic and settled would be my take on the GEM run this morning. The HP for the Bank Holiday weekend is easing away but the ridge from the Azores id heading NE through Ireland and western Scotland so a continuation of decent weather. Note the shallow LP to the south however which brings a risk of showers to extreme southern areas but most places will be fine and dry. GFS 00Z OP at T+240: Another evolution from GFS. The HP keeps well to the north and the LP becomes a cut-off feature well to the west of the British Isles so for most the weather remains warm and settled but with a growing risk of rain or showers for south western parts. Note also the profile around Greenland which in contrast to ECM and GEM and shows heights and warmer air. Further into FI and heights remain strong to the north throughout with winds mainly from the east. GFS 00Z Control at T+240: Very different again. Weaker heights to the NE and the trough coming SE into Ireland and western Britain so a much more unsettled prospect. Further into FI and the LP initially is close to southern Britain before retreating slightly SW and at far FI the OP and Control are actually quite close in terms of evolution with Control setting up an easterly pattern. The 00Z GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 The key message to my eye is HP is close to or just to the north or north east of the British Isles but little sign of a strongly Atlantic pattern with only two or three Members suggesting it by this time. Further into FI and there's a surprising lack of spread suggesting a strong signal for northern blocking for the middle of the month and beyond. In summary, after the forthcoming fine weekend plenty of disagreement over future developments. ECM and GFS suggest a breakdown from the NW with the trough dropping close to (GFS Control, ECM OP) or to the west of the British Isles (GFS OP) with only GEM OP keeping the weather relatively settled though with hints of problems for the south and indeed further into FI the signal of heights to the south with pressure lower over the south and south west seems to be quite noticeable as we move into the middle of the month and beyond but we often see this in low-res and it doesn't translate as we come into high-res. Anyway, some pleasant days in the near future to enjoy.
  8. Here in lowland East London we've had a fair bit of rain so far. At the moment it's light and intermittent but we've had some heavier bursts especially earlier this morning. The rain band is moving slowly westwards but the heaviest rain is currently well to the south over the Channel and northern France. It may be the small LP is just taking its time before it moves NE and starts pulling the rain band more north west and back over the London area. It looks in for the day with a clearance just in time for sunset.
  9. Morning all It doe seem as though some may get a final taste of winter later this weekend and into Monday which looks a particularly cold and unpleasant day for many but it's May (nearly) so in the battle between the warmer and colder air masses which has characterised the past two or three months the warmer side is getting the upper hand but it's been a real spring of contrasts which can be blamed on the weaker influence of the Atlantic. Moving on and looking at where we might be on Bank Holiday Monday, May 7th, and starting as always with the ECM 00Z at T+240: It all ends perfectly well for fans of warm settled conditions but the start of the week won't be pleasant with a couple of unpleasant cool wet days. As the LP moves off and fills, the Azores ridge builds through the south midweek and then transfers to the east setting up as a new HP cell over the southern Baltic leaving the British Isles in a warm ESE'ly wind for the Bank Holiday Monday. GEM 00Z at the same time: A very similar evolution in broad terms to the ECM. The HP ends up over Scandinavia with the ridge aligned SW back across the British Isles and a light NE'ly but still very pleasant. The critical moment is on Tuesday when the LP looks to dive SE across the British Isles but the ridge from the Azores gets there first. GFS 00Z OP at T+240: Something slightly different from GFS. The overall evolution is initially similar but as the HP transfers across the British Isles it declines and the core of heights never develops as a new cell over Scandinavia but is a ridge to a core much further north. In addition, the LP over the Continent is more pronounced and much closer so it's an E'ly flow but with a risk of showers for southern and south eastern parts. Further into FI heights remain to the north with LP to the south so it's variations on a mainly E'ly flow but quite a messy evolution. GFS 00Z Control at T+240: Very similar to yesterday with the Atlantic very much in charge and a fresh W'ly wind over the British Isles. Further into FI and the flow becomes more amplified ending with a developing LP over Europe and an E'ly for southern parts. So, two very contrasting GFS evolutions at T+240 so let's look at the GEFS: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 I'd say the emphasis is on an anticyclonic evolution but where the HP sits and how it is oriented is far from clear. I see more support for an OP type set up than the strongly Atlantic evolution favoured by the Control (though that has some support as well). The Mean suggests HP to the SW and that's well advertised. Further into FI we get our usual signal of heights to the NW but no strong trend as we move into the middle of the month apart from the obvious of no warm southerlies or cold northerlies. In conclusion, the evolution for the next week or so looks fairly well defined, After an unpleasant 48 hours or so especially through Monday, the ridge builds back from the SW drying and warming the weather through midweek. From there GEM and ECM build the HP over Scandinavia ushering in a new period of warmth but GFS is less convinced and the threat of showers from Europe remains or the whole pack of cards collapses as the Atlantic returns. The GFS OP this morning intrigues with further strong northern blocking as we move into May (not atypical) so we'll see where that goes after the weekend.
  10. Morning all A huge contrast from today to this time last week when we were heading toward 29c in London. - currently 14c and raining. Anyway, before the Mods remind me how off topic I am, back to the models and the medium term analysis taking us to Sunday May 6th and the middle if the first May Bank Holiday Weekend. Starting as always with ECM 00Z OP at T+240: The ECM OP run isn't that bad if you like warm, settled conditions but it requires going through a week of more unpleasant conditions. Essentially, LP develops to the south over the coming weekend and into early next week bringing a brief spell of cold and wet conditions before the ridge builds in from the south west and settles the weather down before drifting east to sit as a large cell over the North Sea and Southern Scandinavia with a slack ESE'ly over southern parts. GEM 00Z OP at T=240: A curious offering this morning. A large and strong HP develops to the north of Scandinavia and moves south instigating a strong ESE'ly over southern Scandinavia and a weak trough in the southern North Sea. At the same time, the Azores HP organises and ridges NE so by T+240 it's all very anticyclonic, fine and settled. GFS 00Z OP at T+240: Another evolution but again it all ends very settled for southern and eastern parts of the British Isles with a long ridge of HP from the Azores. The Icelandic LP meanders around but with a positive tilt so the north and especially far north west will always be prone to rain and drizzle. Further into FI, with pressure building to the NE, the door is opened for the trough to push through or just to the north of the British isles so more average conditions moving into the middle of the month. GFS 00Z Control at T+240: All very average. Less settled than the OP with LP more in evidence to the north and a new LP swinging in off the Atlantic. Further into FI, it gets almost autumnal in aspect with some vigorous LP systems about and plenty of rain and strong winds for all. GFS 06Z OP at T+234: Less settled than the 00Z OP and tending more toward the 00Z Control with the HP looking to be squeezed out by encroaching Atlantic LP. Further into FI and there's a brief and quite unsettled spell before HP builds in again from the SW. There's a clear divergence once again between GEM/ECM and GFS. The former is more strongly anticyclonic keeping a signal for northern blocking and generally keeping the Atlantic at bay. GFS is quite different with the Atlantic becoming more dominant again (and potentially quite autumnal) before a return to more settled conditions by mid month. NO sign of cold northerlies or warm southerlies at this time - the pattern looks quite mobile. In summary, despite one or two signs from GFS, fans of warm, settled weather should take heart from the morning's output. There will be a week or so of poor conditions to get through but as we go further into May the signal for something settled has gained strength. It's more likely to come from the SW than the East so perhaps warm rather than hot at this time but nonetheless perfectly reasonable. Finally, for a bit of diversion, here's a nice wintry chart for Christmas Eve, a mere 5,820 hours away !!
  11. To add to the above, the GEFS 06Z at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 To this observer, the OP looks a little isolated but the Control looks more reasonable. It's a mixed bag and while some members bring in the ridge from the SW, the majority have LP close to or just to the south of the British Isles. In far FI, the 06Z GEFS keeps a strong signal for blocking from the NW or NE but as that so often fails to last into high-res I'd be very cautious at this time.
  12. Morning all The post-early summer blues seem to have set in with a vengeance but it was always probable in a year like this with a moribund Atlantic and an SSW that we would be contrasts between the warmer and colder air masses and, to be blunt, it's still April. Snow in May on higher ground in Scotland isn't unusual and frosts even in the south far from a rarity. The journey goes on and so must the medium term analysis which this morning takes us to Friday May 4th and as always kicking off with the ECM 00Z at T+240: ECM this morning has backed away from its own 00Z solution of yesterday to the GFS solution from yesterday which has the LP moving SE from Iceland toward the British Isles. GFS had the LP passing to the west of Ireland but ECM looks like bringing the LP down over the British Isles so the promise of a poor first May Bank Holiday. The Azores HP is too far away to be of any value. Increasingly unsettled and cool conditions for most with rain or showers especially for northern and western parts. GEM 00Z at T+240: A completely different evolution and more in keeping with the GEM of yesterday morning. The trough coming from the NW is held at bay by a ridge from the Azores at the critical point of T+180. The LP fills in situ to the north and the next LP from the Atlantic comes on a positive alignment allowing heights to build from the SW and by T+240 we have a new HP centred over Denmark and the southern North Sea with a light ESE'ly flow bringing fair and warm weather for most with only the far north west of Scotland bothered by Atlantic drizzle. GFS 00Z OP at T+240: Better than yesterday which wouldn't be difficult. LP over central Europe but meandering east allowing the ridge to come up from the SW and link with emerging heights over Scandinavia so a decent outlook with a light NE'ly over the south cooling things down but fine for most. Further into FI it remains fairly settled with HP never far away from the south west so southern and western areas generally settled. Always a threat of rain for more northern and eastern parts - cooler too with occasional NW winds. GFS Control 00Z at T+240: A cool and showery (especially for the north) WSW'ly flow with a ridge to the south of the British Isles into Europe but LP close to Iceland. Control, like the OP, keeps the onus on more settled conditions with increasingly influential (and large) Azores HP extending the ridge NE so decent conditions for early May for many. By way of contrast, here's the GFS 06Z OP at T+234: Very different with a cool NE'ly over the British Isles and a deep LP over central Europe though what we have is NOT the LP that comes through the British Isles but a separate LP moving up from Africa which is invigorated over the Med and by our LP and becomes an active system for an inland depression.
  13. Indeed GEM looks poor through next weekend and even into Monday but it gets the LP out of the way quickly to the NE leaving a col before the HP ridge builds in. ECM takes the LP just to the east so a poor second half of the weekend for southern and eastern parts before the LP shifts NE and the HP can build in so late Monday into Tuesday is the key moment. As for GFS 00Z OP, the LP doesn't clear away cleanly, part of the energy goes south, part hangs over the British Isles so the negatively aligned trough comes into the space and the HP is shut out. That's the pivotal point of the evolution but the GFS is following the pattern from later this week of having the trough drop through the British Isles from the NW and become absorbed in the LP to the south re-invigorating the LP and controlling the pattern through the weekend. Whether the GFS is simply seeing the repetition of the pattern while the other models are trying to break out of the pattern (by a default reset to an Atlantic-dominated westerly pattern) I don't know. The GFS OP is following what we saw a lot through the winter with negatively aligned troughs sliding SE rather than following the conventional west to east movement - a product of an amplified or weakened jet stream ?
  14. Morning all Last week's exceptional spell of warmth is already fading into memory. Much cooler and cloudier in London this morning after five days in the 20s and a couple above 25c. The problem is in a year with an SSW and a moribund Atlantic the extremes of warm and cool which are usually tempered by the Atlantic and the average westerlies, are able to come forward with air flows from the SE or indeed NE more common with the resulting contrast in temperature between air masses. So will the beginning of April see fridge or furnace, bbq or hot bevvy ? Today I'm looking ahead to Thursday May 3rd and starting as always with the ECM 00Z at T+240: In the end, a decent chart with a long ridge of HP from the Azores covering most of the British Isles bringing increasingly settled conditions but the journey to this chart isn't pleasant with plenty of LP close to or over the British Isles in the next week. GEM 00Z at the same time: Not too far removed from the ECM though with a deeper Atlantic LP and a more displaced Azores HP but still a ridge over the British Isles allowing things to dry out after what looks a very unsettled and wet weekend ahead with LP to the south of the British Isles moving north over England. GFS 00Z OP at the same time: A very different evolution and it starts with the trough becoming negatively aligned rather than the positive alignment with GEM and ECM which allows the ridge to be thrown forward from the SW. With GFS the LP forms to the west of Iceland and swings SE to the west of the British Isles as HP builds in mid Atlantic behind it. At T+240 the LP is to the west of Ireland with a light SW'ly over much of the British Isles but rain or showers likely especially for western and south western areas. Further into FI, the trough elongates across southern parts before the core LP moves eastward then SE to northern France leaving most parts in an easterly flow with improving conditions for northern and north-western parts. GFS 00Z Control at T+240: On the Control, the ridge "beats" the trough so before the LP can slide SE, the Azores HP is ridged across the British Isles so a drier and warmer evolution with most areas beyond the far north dry. Further into FI and the large Azores HP remains in charge but its position and orientation doesn't allow for the advection of warm air from the south - instead, the flow is mainly west or north-west so settled but only average temperatures for most. The GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 A real mixed bag with as much spread as I've seen for several days but essentially we've two scenarios (or variations) in play. One brings the trough down over the British Isles with ridging to the NW behind it and the other gets the ridge over us first and keeps the LP systems to the north of the British Isles. Glancing further into May and the signal for heights to the north remains evident with the OP solution having more support than the Control at this time. In summary, a much cooler and progressively more unsettled week ahead culminating in what looks a potential washout for southern parts over the coming weekend as the LP to the south develops and moves across southern Britain. From there, two scenarios come into place - GEM, ECM and GFS Control keep the LP to the north and bring a ridge back across the British isles from the south west but GFS OP has a more negatively tilted trough which comes SE with the mid-Atlantic ridge building behind and ushering in a period of renewed easterlies with LP setting up over Europe. I imagine many in here will want the former for obvious reasons but the latter isn't without support on the GFS suite and the signal for northern heights further into May remains strong as we move further into the new month. Let's see where this journey takes us...
  15. Morning all First, kudos to those who called the heat correctly. I didn't think it would get past 25c in London let alone to near 29c and for all this we can think the SSW and the Beast from the East. A moment - northern blocking and, more importantly, the trough to the south of the British Isles or over Europe meant warm air funnelled from Africa up over Eastern Europe so the Balkans got an early spring with 22c in Belgrade as early as March 12th. When the set up returned over Easter another warm plume moved up over south eastern and eastern Europe (24c in Belgrade on March 30th). That meant when the synoptics enabled sir to be sourced from the SE said air was unusually warm and with the minimum fetch over the cool North Sea and aided by the strengthening sunshine, we got the record temperatures we have seen. Without the modification of the Atlantic, more continental-type climactic events are possible and in many of these the transition from winter to spring can, in temperature terms, be rapid. Look at what happens in North America and Siberia as winter eases - huge contrasts in temperature can be experienced even on a daily basis. Worth thinking about IF the Atlantic becomes less influential in our weather and climate. Back then to the models and some thoughts on where we will be at the end of the month based on the morning output so it's Monday April 30th and starting with ECM 00Z at T+240: Back to a more normal pattern from next week with our weather coming off the Atlantic. LP to the NW and HP to the SW and by T+240 a broad ridge from the (slightly displaced) Azores HP hints at decent conditions for most while LP is gathering to the west of Iceland and may become more influential as May starts. GEM 00Z at the same time: A more unsettled evolution. GEM re-orients the Azores HP more to the west and north and that allows the trough to drop SE over the British isles so we end up in a very unsettled pattern with slow-moving LP bringing plenty of rain or showers. GFS 00Z OP at T+240: Once again GFS teases with an E'ly but it wouldn't take much for the GEM evolution to reach a similar point or even the ECM evolution. GFS has LP to the south west and heights build to the NW from the Azores using the "up and over" approach with the ridge inclining toward Scandinavia. A warm pattern given the air source with showers or perhaps storms for the south but fine further north. Further into FI the easterly pattern continues for southern and eastern parts but then shifts to a NE'ly and introduces a brief much colder air flow. GFS 00Z Control at the same time: A chilly northerly as the trough edges east and heights try to build in from the west. A more progressive version of the GEM evolution in my view. Further into FI, however, things turn much drier and warmer as a large HP builds over Scandinavia and ridges back SW across southern parts. The GEFS for 00Z at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 A really mixed bag. Fans of heat can go straight to P10 which would rival if not surpass the current warm spell while fans of cold can go to P11 for their daily fix and while there doesn't appear to be a lot of spread the truth is for our tiny island slight changes in position and orientation of large weather systems can have huge impacts. The only trend I see is no trend. Mean puts LP close by and that's well supported and you can't go far wrong with that as a forecast but I'm struggling to see a clear message even at this range. In summary, the fine spell is a memory by Monday and next week looks to be more "normal" with a westerly pattern off the Atlantic. From there, the evolutions are varied - both GEM and GFS push LP close to the British Isles, the former has it over us and the latter to the south pulling in a prolonged spell of easterly winds. ECM keeps heights closer but you wonder if the trough at T+240 might not swing SE from its position west of Iceland.
  16. Afternoon all I'm not a fan of summer in all honesty but I don't begrudge people a little bit of warmth now and then and especially after such a long winter and slow spring. The turn round has been remarkable and it looks as though tomorrow will be the height of the warm snap. Looking further ahead, clear signs of a return to something more normal next week. GEM has a very contrasting view to next Wednesday from today: ECM at a similar place: GFS 06Z OP as well: Further into FI 06Z OP pulls out something nice for early May: Once the cool NW'ly goes by next week things get much more uncertain. Perhaps a hint of LP close to or just to the south of the British Isles but far too early to be clear.
  17. Morning all While some quibble over whether it'll be 22, 23, 25 or 27c on Thursday (and for those of us stuck in an office and unable to take part in the seemingly obligatory BBQ it's immaterial) the weather moves on its merry way oblivious to our wants, needs, hopes and desires. Yesterday the post-heat breakdown was looking quite messy but let's see if anything approaching clarity has arrived as I look at the output for Friday April 27th and start with the 00Z ECM at T+240: To be fair, ECM keeps the fine spell going through the weekend and into next week by a new push of heights to the north and then the east of the British isles but the break down is only postponed and by T+240 a fresh W'ly regime is in place with LP to the north and HP to the south west so always drier and warmer to the south with rain or showers further north. GEM 00Z at the same time: GEM breaks down the fine spell much more quickly than ECM (it's gone by Monday on the former) and from then on it's a WNW'ly with broad if reasonably shallow areas of LP on a slight negative tilt moving from the area south of Iceland crossing Scotland and into Europe. HP is suppressed to the south so it's a cool and changeable outlook with periods of rain or showers for many but the rain always lighter to the south. GFS 00Z OP at T+240: Slightly different but the overall evolution is similar to GEM. The fine spell is replaced over the weekend by a cooler W'ly form and there's a NW'ly by T+240 as the trough migrates to Scandinavia pulling in cooler air. Signs perhaps of a pressure rise in mid Atlantic behind and while it doesn't happen at once the Greenland HP re-asserts and the trough sinks close to the British Isles further into FI. The resulting air flow is sourced from Scandinavia so won't be warm. GFS Control at the same time: Very unsettled with rain or showers for most. Further into FI, a ridge builds north from the Azores and across northern Britain into Scandinavia bringing a return of some warmer air. The 00Z GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 The 850s tell a clear tail with most having negative values across the British Isles by this time. The OP representative of the suite in my view with the majority suggesting a cool NW'ly flow - one or two go further and have a N'ly. Only a couple of members keep a warmer S'ly component by this time so it looks all over for the fine spell by this time. Further into FI and easterlies are appearing as is the Greenland HP but that's by no means a done deal by this time. We often see a colder interlude in late April or early May and this year looks set to be no exception. In summary, some fine warm and sunny days in the near future but the breakdown is clear and into next week it looks like a deteriorating situation with more changeable and cooler conditions encroaching from the north and west. From there, it's still unclear but the end of April and beginning of May are often colder and more unsettled and this may again be the case with the possibility of the Greenland HP building down and introducing something more N'ly in nature. As ever, more runs are needed.
  18. Morning all A new week but very different weather coming for large parts of the British Isles as a large LP stalls in mid-Atlantic and a plume of much warmer air moves from the SW leading to the formation of HP to the east and the importing of even warmer SE'ly air midweek. Some are claiming we could exceed 25c by Thursday - I'm sceptical - but certainly a spell of temperatures more akin to June than April seems on the cards with London experiencing several days with day time maxima above 20c. Will it last ? The medium term analysis this morning takes us to Thursday April 26th and starts as always with ECM 00Z at T+240: After the initial HP has declined, a ridge builds in from the Azores to promise a continuation of fine weather through the weekend but early next week the writing looks on the wall as LP moves down from the north and by T+240 the trough extends from Scandinavia through the far north of the British Isles with a cooler WNW'ly airflow in place. GEM 00Z OP at the same time: Slightly more complex. GEM hurries the breakdown and the NW'ly is in place by next Monday. However, weak heights remain to the south but with slack troughs too in quite a messy synoptic evolution. By T+240 basically settled and especially so for central areas. Perhaps an increasing risk of showers for south-western areas and the far north west under an Atlantic influence with a threat of rain or drizzle. GFS 00Z OP at T+240: Recognisably close to ECM though does have the messier evolution to the south of GEM. Cooler than in the coming week with a noticeable WNW'ly airflow and rain or showers especially for northern areas. The south perhaps hanging on to some better weather but nowhere near as warm as it will be in the coming week. Further into FI it all looks very average with attempted ridging from the Azores flattened by Atlantic LP systems and continued weakness to the south, especially over Iberia, as we often see as summer approaches, threatening more disturbed weather for southern parts. GFS 00Z Control at the same time: Not too different to the OP in all honesty. Further into FI very average with a W'ly flow. The 00Z GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 OP and Control following the Mean which you always like to see for verification and a strong cluster supporting that evolution. Just one Member keeping HP to the east but a few also interested in building Greenland heights once again though I would be sceptical. Further into FI no clear signal to end the month and start May. As you've all been well behaved, here's a treat with the 06Z OP at T+234: Make of that what you will. However, FI gets much more interesting with the trough to the SW deepening into a serious LP area and with heights building to the north and NW we get an E'ly !! Rain (and possibly plenty of it) for southern and south western parts but fine for the north but cool with a hint of NE in the air flow. In summary, a fine summer like spell of weather starts tomorrow or Wednesday (depends on your definition of summer I suppose) and the south should squeeze five or six decent days out of it, perhaps less so for northern areas. By early next week, all the models are indicating a breakdown to a more traditional Atlantic-dominated pattern but not because of a raging Atlantic by any means. Slack areas of LP and weak areas of HP proliferate and it's all quite messy for the last week of the month but temperatures will return to where they should be for most. No signs in far FI of anything too hot, too cold, too wet or too dry to be honest and for those following the old weather maxim of April going out "like a lamb" you may well be right.
  19. Afternoon all Plenty of people salivating at the prospect of some warm, sunny weather which is understandable after a long winter and one of the slowest starts to spring I can remember. From some of the talk, it seems however we will miss spring and go straight to summer. Not much sign of spring, it has to be said, in my part of the world this week. Never mind, let's see where we may be on St George's Day, Monday April 23rd and let's kick off with what seems to be everybody's favourite model at the moment for some reason, the ECM, the 00Z at T+240: Not hard to see why this should be so popular. ECM has been the most bullish about a short-lived warm spell for some day and is now bringing back renewed HP from the SW so fine and dry weather for most though perhaps not quite as warm as it's due to be next midweek with the air coming off the Atlantic but nonetheless very pleasant. The far NW still at risk from Atlantic systems and some drizzle perhaps and note the LP over North Africa helping to prop up the new HP push. GEM 00Z at T+240: A rather different evolution. By this time next midweek's HP has declined to the SE but while there's a weak LP over Biscay winds are light over the British Isles in a col. There's a weak ridge pushing north and a sense that heights could well be developing to the north of the British Isles with the Atlantic moribund but we'll see. GFS 00Z OP at T+240: Closer to ECM than GEM but with a different evolution again. Heights to the east eventually break down as a deep LP comes in to northern Scandinavia. This enables a height rise over the British Isles but the trough is still over Iberia so the HP is inflated to the north. Further into FI, Atlantic LP comes back into control and the run ends quite unsettled and much cooler with a NW'ly flow. GFS 06Z OP at T+234: More like the morning's ECM with a renewed push of HP from the Azores. Further into FI and the pattern of heights to the north and the trough to the south re-asserts so a messy evolution with occasional E'ly interludes but always more unsettled to the south. GFS 06Z Control at T+240: Something very different. Heights to the NW, a large tough over Scandinavia and a slack N'ly driving out the warmer air and returning colder conditions for all. Further into FI and a NE'ly interlude before a new LP develops near Iceland and disrupts SE over the British Isles. The 06Z GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 In my view, the Control solution has far more support than the OP and indeed fans of warmth should look at P19 if they want to choke on their lunch. Others raise heights to the NE and offer a NE'ly flow while the OP's desire to remove heights to the south of the British Isles isn't widely supported in the ENS at this time. The path beyond is much less certain but northern blocking is well represented as well as the tough sitting over the British Isles with warm, settled conditions in the minority. To conclude, a fine and warm snap lasting 2-3 days next week looks certain but the breakdown of the HP to the east and what follows is far from clear. Fans of warmth will draw heart from ECM and the GFS 06Z OP while GEM and GFS 00Z both pointed to an alternative which kept LP to the south and seemed to suggest new heights to the north. The GFS 06Z Control has thrown a spanner in the works with an evolution which is not without support in the ENS and raises heights to the NW. An intriguing evolution beyond the warmth of next week and as we often see at this time of year, with a generally moribund Atlantic, the position and orientation of HP becomes of more significance.
  20. Morning all Continued excitement at the prospect of two or three days of very warm weather next week and certainly 21-22c next Thursday will be much higher than the 12c currently on offer. Let's see where the end of next week finds us so today the medium term takes us to Sunday April 22nd. Starting as always with ECM 00Z at T+240: The orientation of heights changes from the east to the SW of the British Isles but it remains fine for many albeit probably a shade cooler with air sourced off the Atlantic. It's likely northern and western areas will turn more unsettled as the LP approaches. GEM 00Z at T+240: The principal difference between GEM and ECM is ECM removes the trough to the south of the British Isles while GEM keeps it. The presence of the trough means heights are pushed further north so there is a light residual E'ly across southern areas while northern and north western parts keep fine conditions with little or no Atlantic influence. GFS 00Z OP at T+240: GFS breaks down the warm spell slightly more slowly but slightly more completely with LP spreading up from the SW to cover the British Isles bringing in rain or showers for many by this time. No sign of an Azores ridge at this time but a strong ridge holds around Greenland and this dominates the weather into FI as the trough drops into Scandinavia and across the British Isles bringing much colder and more unsettled conditions for all. GFS 06Z OP at T+234: A cooler NE'ly flow as HP has retrogressed toward Greenland but still fine for most. Further into FI heights remain to the North or North West and in time the wind becomes more N'ly introducing much cooler air. GFS 06Z Control at T+240: HP to the NW and keeping things settled for most. Heights remain close to or to the NW of the British isles further into FI but with signs of a more N'ly incursion later. The 06Z GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 Broadly anticyclonic though the position and orientation of the HP far from resolved though the majority keeping the centre to the north of the British Isles. Further into FI a signal for the heights to move more to the NW and the trough to drop into Scandinavia so much cooler conditions with a N'ly component to the sourced air flow. In conclusion, if you want spring/summer to continue, ECM is the form horse as it looks to rebuild heights from the south. GEM goes a similar route but keeps residual LP to the south so tempering things a bit but if you want something else, head for GFS. The 00Z OP is a real slap in the face for warm fans and while the 06Z keeps things settled for longer, the signal for a change to a colder more unsettled outlook with heights retreating NW and the trough dropping into Scandinavia is clear but far from certain at this time.
  21. Afternoon all Lots of people getting excited about next week's brief warm up which is understandable after the long winter we've experienced. However, the weather doesn't care what we want or don't want and goes on its merry way. Today I'll take the medium term analysis out to Saturday April 21st and start as always with ECM 00Z OP for T+240: The evolution is different to yesterday's 00Z and more closely resembles the GFS 00Z from yesterday. The HP is basically an extension of HP over western Russia which shifts west as the Atlantic LP stalls but the warm snap isn't going to last as the HP quickly declines South or South East and a new trough develops to the SW of the British Isles developing into LP and frontal rain coming NE. The SE is likely to see only light rain but Ireland would get more noticeable rain. GEM 00Z at T+240: Something different from GEM as pressure rises NE from the Azores and the trough shifts north so a generally fine and dry prospect but with the wind shifting from the SE to a west or NW'ly temperatures would ease back from their midweek highs. The far NW would see rain or drizzle from Atlantic systems. GFS 00Z OP at T+240: Different again. The Scandinavian HP which was at one point a large and intense HP is declining but in situ so the SE'ly flow across the British Isles remains but the LP is now well into south western areas bringing rain and heavy showers to an increasing area while the north and east hangs on to something drier. Further into FI and the evolution remains messy but with heights to the west and later the north west it's a drier but cooler prospect. GFS 06Z OP at T+234: Well now, is that a retrogressing HP I see ? It's an interesting new development which I've not seen to now. The ridge keeps northern and eastern areas largely fine and warm but the LP is approaching the SW hinting at something less settled in terms of showers. Further into FI heights remain dominant to the north with the air flow over the British Isles ranging from a cool NE'ly to a warmer E'ly as we approach the end of the month. GFS 06Z Control at T+240: Heights rising to the NW and more of an ENE'ly flow as pressure drops over Scandinavia. The LP is still well to the SW over NW Spain so the weather remains fair for most away from the east coast. Further into FI and signs of a return of Atlantic influence as LP develops to the west of Iceland and promotes a broad SW'ly flow over the British Isles. The 06Z GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 Plenty of warmth and/or northern blocking. The orientation and position of the HP varies considerably across the suite and has a huge impact on the air flow reaching the British Isles (don't look at P6 if you're a warmie). I'd say more uncertainty than the past couple of days and the eventual "breakdown" of the midweek warm snap still hard to call with retrogression a clear option based on the OP. Further into FI and the clusters are heading down two distinct routes - one favours a return of Atlantic influence while the other keeps northern blocking but more toward Greenland with a trough either over Scandinavia or closet to the British isles with a risk of a cold N'ly or NE'ly outbreak toward the end of the month. In summary, next week's 2-3 day warm snap will be welcome by many but it doesn't look as though it will hold until the weekend. As the HP declines, LP encroaches from the SW bringing an increased risk of rain or showers from the SW. From there, the Atlantic might return or blocking could continue with more of an emphasis on Greenland or the NW in general which opens the door to something colder (potentially) but we are a long way from resolution on that as you'd expect.
  22. Morning all Plenty of signs for something drier and much warmer next week though for now the painfully slow transition from winter to spring continues in lowland East London. This morning the medium term analysis takes us up to Friday April 20th: Starting as always with ECM 00Z at T+240: The trough close to or over the south of the British Isles dominates the rest of this week but next week an LP stalling and deepening to the west forces heights in front of and to the NE over the British Isles which becomes a new centre of HP over Denmark but it's not going to last according to ECM as the above chart shows the HP declining as a new LP developing to the west of the British Isles moves in. The trough is negatively tilted so will it dive SE or will it brush through Ireland ? Fine and warm weather for much of the east and south under a SE'ly flow but signs of more unsettled conditions coming into Ireland. GEM 00Z OP at T+240: Something very different from GEM this morning. Heights develop not to the NE but to the SE over Europe which is something we've not seen for a fair while. The flow is still a mild or warm SW'ly with the best weather for southern and eastern parts but the HP though broad is quite shallow while the LP is stationery to the west of Ireland so you'd think more unsettled the further west you are. GFS 00Z OP at T+240: After being on its own yesterday, GFS joins the ECM party with HP to the NE but the evolution couldn't be more different. ECM inflates the HP from the Azores with heights from the SW while GFS brings heights westward from Russia into Scandinavia. The HP starts sinking south from central Scandinavia to Denmark and tilts to orient NW-SE and this allows energy from the Atlantic to start to edge SE into south western parts of the British Isles so while it's a warm and increasingly breezy and fine picture for many the south west will start to see increasingly unsettled conditions with showers. Further into FI the trough eventually settles SE just to the south of the British Isles with heights to the north but at the very edge of FI the flow shifts more SE and much colder air starts to encroach from Scandinavia. GFS 00Z Control at T+240: The Scandinavian HP starting to decline but the Atlantic energy split both north and south. The British Isles remains warm and fine under a benign SE'ly flow. Further into FI that doesn't last and it turns very much colder as heights build from the NW and a NE'ly flow sets up over the British Isles. A real temperature contrast would be on offer if this verified. The GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 Strong agreement on heights to the east or NE of the British Isles and a warm SE'ly flow. Some divergence over the exact position and orientation of the HP which is to be expected this far out but the overarching message is the same. Further into FI and all I'll say is fans of cold may yet have one last shot with plenty of Members showing heights to the NW and a NE or a variant of that setting up. We'll see.
  23. Late morning all A damp and disappointing start to the week in London but some signs yesterday of a hint of something better around or just after mid-month. This morning takes us to Thursday April 19th and we kick off as always with ECM 00Z at T+240: A strongly anticyclonic with plenty of dry and warm weather from an HP centred over Denmark. The easterly this week fades by Friday but the Atlantic disrupts north and south as the LP approaches western Europe with heights rising to the east and LP deflected north and south. GEM 00Z OP at T+240: Similar to the ECM and the evolution not too different. GFS 00Z OP at T+240: A very different evolution with persistent heights east from Greenland preventing the Atlantic KLP disrupting north so the whole LP moves SE keeping the weather unsettled especially over southern and western parts. Further into FI and the LP persists close to the British Isles even as the Azores HP tries to ridge in from the SW. GFS 06Z OP at T+234: A more definite ridge south from heights well to the north of the British Isles means a light ESE'ly for most and decent weather with the LP kept well to the SW. Further into FI and a brief flirtation with warmth is replaced by cooler conditions as heights end up to the NE with LP to the SW and SE meaning a broadly northerly flow over the British Isles but the coldest air always well to the east. GFS 00Z Control at T+240: More akin to the GEM and ECM than the OP and a more defined SE'ly flow. Further into FI as the LP approaches from the south, the flow shifts more east and eventually north east as the HP retrogresses to Greenland. The GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 A very strong signal for heights to the east or north east of the British Isles with OP and Control not far apart and leading the majority cluster. One or two Members have the LP a little closer but the net effect t is more wind from the SE rather than anything else. Further on and plenty of uncertainty as you'd expect but with no strong signal for any particular pattern. In summary, plenty of agreement this morning on heights building to the east or north east next week. Whether these develop from a disrupting LP to the west or from Greenland is less clear but the net effect is the same. HP to the east brings SE'ly winds so warmer and drier conditions for all. Southern and South-western areas would still be at risk from rain or showers if the 00Z OP verified. GEM and ECM break up the LP and send energy both north and south while GFS moves everything to the south or south east. Quite possible we'd see 20c from the GFS Control, the GEM or the ECM but the east coast would still be at risk from fog.
  24. Looking at the GFS 06Z OP illustrates the problem: If the Scandinavian HP moves too far east, the warm plume of air from the SE passes to the east and north east of the British Isles and instead the trough returns to southern areas bringing back a risk of rain or showers and re-enforcing the slack flow off the North Sea.
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