stodge

Nick's comment (picked up by one or two others since) is completely on the ball. We often see the initial impact of a push on the PV as being substantially negative in terms of "cold" over western Europe as the PV tightens and the zonal winds increase in response. No one can be surprised if we have to enjoy/endure a 7-10 day period of Atlantic domination (and the best we can hope for within that is cool/cold zonality) before the tropospheric response to the stratospheric response becomes clear. Given the pressure on the vortex from now until the projected split next weekend and then renewed pressure on each of the vortices I'd anticipate a frustrating milder spell mid-month before we see where the pattern takes us later in the month. Without wishing to sound too downbeat, it's worth pointing out the vortex split offers us only a place at the table - it doesn't guarantee a winning hand of Easterlies. Still, 18Z Control offers one option which will be attractive to many: Everything I've seen today in far FI suggests a slowing weakening Atlantic and jet as we move past the middle of the month. Obviously, that offers some possibilities which may be from the NW or the East. We'll see.

Afternoon all I won't do a full medium term model summation but irrespective of the next 96-120 hours which I'll leave to others, I've never seen much prospect of a continued cold period without any kind of less cold/milder interlude. That seems more and more likely in the form of a stormier and unsettled spell around mid month as the Atlantic stages what is, I believe, its last hurrah. So after this week's cold spell a general easing into mid month and then 7-10 days of Atlantic weather before the next big pattern change which is being well signalled in the MJO, the stratosphere and elsewhere. The manifestation of that pattern change isn't anywhere near settled but plenty of the GEFS in far FI are looking at height rises to the north and east. The key is or will be the decline of the Atlantic as the influence of the split vortex lessens. None of that guarantees cold weather or snow - we could easily finish up dry and cold or even dry and very mild - but we are much more in the game than if facing a relentless PV. One thing is certain - model watching won't be dull this month.

Afternoon all Unfortunately it's all often the case that when the charts get interesting my life gets busy. As so many others, I've enjoyed watching this hopefully interesting cold spell emerge from almost nowhere earlier in the week. There's a lovely animation over on the Finnish Met Office website showing the HP developing from above the point where Finland, Norway and Sweden meet and growing from 1020MB to 1035MB in just 12 hours and extending SW. http://en.ilmatieteenlaitos.fi/marine-weather-and-baltic-sea While you're enjoying that, I'll take a look at the medium range model output which today is going to take us out to Monday February 12th. Starting as always with ECM 00Z OP at T+240: A cold- looking chart though uppers are only -4 for most. Of more interest is the block re-developing over Scandinavia and the movement NW to SE of LP areas and the hint this movement could retrogress further west. Unsettled with rain and snow to altitude for many. GEM 00Z at T+240: GEM has never bought into the upcoming cold spell and has been dragged kicking and screaming to the table in the past 24 hours. Even now, it's a short-lived colder blip before the Atlantic rushes back and this is a very mobile chart with rain or showers for most with a cold front clearing through the British Isles. GFS 00Z OP at the same time: GFS has always played the anticyclonic card and continues to do so here. A brief milder segment embedded within the WNW'ly flow but generally benign and dry for most part from far NW parts which could see a little drizzle. Further into FI and the HP remains in charge with retrogression to an emerging Greenland HP. GFS 06Z OP at T+234: A more mobile and colder pattern with a strong WNW'ly flow off a chilly Atlantic. A secondary LP approaching the SW Approaches threatens enhanced rain and snow to elevation with some cold HPAs (below -8 over Scotland) in place. A colder evolution into FI with a NE'ly over the south which looks set to draw in some very cold air. GFS 06Z Control at T+240: Not hugely different to the OP - a brief quieter spell under a transient ridge before more rain and wind from the west. The Control also ends very cold with a NE'ly flow setting up behind an emerging Greenland HP. Looking at the GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 My observation would be a good number of colder options especially where the British Isles is under a cold col between pressure systems to the east and west. That looks our best prospect for a continuation of colder conditions into the medium term. A number bring in vigorous LP systems where there are milder options as well. Just looking at the Ens further into FI, a growing cluster favouring much colder conditions and following OP and Control. To conclude, events in the next 4-6 days notwithstanding, the best prospect of maintaining the cold theme through the end of next week is to get the British Isles into a col between systems where stagnant cold air can be maintained. That said, there are other milder options on the table and I'm struggling to see the cold theme surviving by this timer next week. That being said, strong signs within GFS FI for a return to colder conditions after mid month with a renewed thrust of NE winds as pressure builds over Greenland. So it could be very cold, less cold, mild, very cold as a sequence for the next fortnight. My final caveat is given the dramatic model evolution of the past 72 hours and the varied evolutions shown by the main models, confidence in any medium term evolution has to be low. Developments elsewhere offer encouraging signs of possible pattern change (GFS 06Z FI ?) but we'll know a lot more as time goes on.

Afternoon all Plenty of interesting comment and I hope for everyone's sake we get a decent shot of cold/snow. From the 06Z GFS Ensembles I'll take P10 all day every day for the next two and a bit weeks.

Morning all MY chance to look at the medium term model output this morning. Last week showed teases aplenty in FI regarding easterlies and Scandinavian blocks but perhaps that's all they ever were. We have a sharp colder blast this week and perhaps over the weekend too but that's not what most on here want and I suspect cold and dry won't cut it either. Some encouraging signs from the teleconnections however for further into February but perhaps too early for the model output at this time. Anyway, this morning we're looking at the models for Friday February 9th: Starting with ECM 00Z OP at T+240: After last week's teases, a classic winter chart for the British Isles. Between the Azores HP centred over the Azores (no surprise there) and a deep LP over Iceland the British Isles is in a WSW'ly flow. A transient ridge is coming in to cross the British Isles so a quieter spell before more showers or rain from a following trough which might well form a secondary feature. On to GEM 00Z at the same time: Some people are very rude about GEM but this model has, in my view, done very well of late. It has wanted nothing to do with phantom E'lies or Scandinavian ridges apart from a brief flirtation which gets swept away rapidly. It does over-blow Atlantic LPs on occasion and may have done so here but the British Isles is in a cold NW'ly flow with sunshine and showers and wintry to high ground I'd imagine. The angle of the trough is well into Europe so the Azores HP has no option to topple so this version of cold/cool zonality which we've had for much of this winter continues. GFS 00Z OP at the same time: A recognisable blend of the above solutions and after last week's huge divergence, it's pleasant to see more unanimity across the models so it's a W'ly flow from GFS this morning but a small transient ridge crossing before more unsettled conditions and an interesting little LP lurking between the two HP cells so let's see where that goes further into FI. That does cross the British Isles but the mode into the middle of February is stormy and unsettled as a lobe of PV energy drops into the Atlantic in the form of a major LP. Some indications in the 10HPA strat profile of a new and unusually placed warming but we'll need plenty more runs to see if this is indicative of anything. GFS 00Z Control at T+240: A more sharply-aligned trough here so a cold and unstable NW'ly flow for the British Isles with the likelihood of snow to higher ground. Very unsettled to the end of the run but perhaps just a hint of the Atlantic weakening. Looking at the GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 A single rogue E'ly remains but plenty of cold N or NW'ly options out there and our old friend cold zonality which played so well for much of the north a couple of weeks ago may make a come back in February when such a flow would still be potent. In summary, for fans of snow in the lowland south it's a bleak outlook this morning - for fans of snow in Scotland and on high ground, plenty of opportunities for transient falls. The trend toward a more settled period has ebbed away and the powerful jet fuelled by the extremely cold and tightly-organised PV is in charge throwing LP after LP across the Atlantic. The Azores HP keeps them far enough to the north not to offer any potential damage in terms of wind or excessive rainfall but those hoping for a prolonged drier spell are going to be as disappointed as those seeking snow. I see more than a hint of our friend cool zonality in the outlook and the potential for a stormy mid-February. Beyond that, who knows ? Hints of the Atlantic weakening as the PV comes under significant attack may offer some hope - the MJO seems to have been forgotten about. One or two charts looking even further ahead suggest late February into early March may see a pattern change but in the short term I see nothing slowing down that intensely cold engine over NE Canada.

Oddly enough, it's the least anticyclonic run I've seen for a while and has echoes of an OP from earlier in the week. Heights from the Pole pushing the jet and associated troughs further south. -4 to -8 uppers so you'd think there might be some wintry possibilities but the southerly tracking jet the big change (but it's all low-res).

Morning all Another day but the same distance away from the future it seems... Some interesting model output in far FI yesterday taking us well into February but like eggs, we'll kept it medium range so looking up to and including February 5th: ECM 00Z at T+240: Not perhaps the stellar output of previous days but not without some interest. Anticyclonic and probably cloudy and fairly mild despite a broadly NW'ly flow. A weak and very cold HP over Scandinavia but you'd think the northern arm of the jet too strong but the T+264 chart would be interesting. GEM 00Z OP at the same time: The OP GEM runs have never favoured amplification this week though it's worth noting how far west the Azores HP has moved. There's a residual ridge back over NW Europe but a second ridge NW and you just wonder if, assuming we can catch a break, there could be some amplification north. Otherwise, it's a mild and fairly benign outlook but with frontal rain moving in with strengthening winds as the LP centres approach. GFS 00Z OP at T+240: GFS delivers the chart of the morning for cold weather fans with a NNE'ly flow and an HP ridging south from Greenland. Uppers are -4 to -8 so snow to high ground and in any heavier outbreaks and cold for all. Into further FI and after a notable five day spell, the cold set up collapses as the Atlantic returns leaving residual heights over Scandinavia by T+384. GFS 00Z Control at the same time: Another cold chart though with a more NW'ly component. The amplification to Greenland hasn't worked and this would be more a 2-3 day cold snap for most before the Atlantic returns. GFS 06Z at T+234: The trough is much closer than on the 00Z OP and the amplification less marked. Still cold and unsettled and probably wintry to higher ground. Further into FI and battle is joined between the Atlantic and a developing Scandinavian HP. The former looks to prevail but it's a very long way off. Finally, GFS 06Z Control at T+240 (there being no T+234): A cold N'ly airflow for the British Isles with plenty of rain or snow. To conclude then, GFS has picked up the cold baton with gusto into medium range this morning though any colder spell looks to be brief before the Atlantic returns. That's something often modelled at the initial stages by GFS which loves to "reset" things but the reality is the colder air and block is harder to shift. The problem for cold fans at the moment is all this remains tantalisingly out of reach at this time and until we start seeing in high-res it's wise to be cautious. GEM goes out to T+240 but has offered nothing all week for cold weather fans. ECM has pitched around like a boat in a storm offering all sorts of fantasy charts at T+240. GFS has been resolutely anticyclonic but has offered more consistent "cold" output this week so far. Is "something" happening or are we all being led up a garden path strewn with red herrings ? More runs are needed..

Morning all An early(ish) look at the overnight model output on a fine but chilly Thursday morning. Looking at the output for Sunday February 4th in the medium range models: Starting with ECM 00Z OP at T+240: Another day, another tease might be the best way to call this. Obviously, IF this verifies, it would be cold but with only -4 uppers probably rain to low ground but obviously snow to higher elevations on the cards but it is what it is and where it is. GEM at the same time: Couldn't be more different. A long ridge of HP going into and covering much of western and central Europe with the cold Siberian air deflected to the far SE of Europe. For the British Isles mild or very mild and generally dry in the south but more unsettled and breezier further north with rain never far away. The jet is well to the north so little or no sign of winter on that chart - indeed, spring might well be in the air with temperatures in the south into the low to mid teens. GFS 00Z OP at the same time: A blend ? Well, maybe or maybe not. A large area of HP centred just to the SW of the British Isles is a GFS model favourite - the orientation is more interesting with the ridge aligned NW-SE. That keeps the British Isles in a NW'ly airflow but the air isn't that cold. Note the LP development over the Azores which is profiled very differently to both ECM and GEM and has a big impact on the HP's orientation, It has to be said the further evolution into FI is about as good as it gets for cold fans. The HP ridges north then NE from T+288 and ends up as an intense feature over northern Scandinavia at T+384. Fantastic eye candy and were it to verify, it would be a significant change to an E'ly regime over the British Isles with increasingly bitter air and the likelihood of snow. For now, though, eye candy is all it is. GFS 00Z Control at T+240: One of the reasons the OP FI looks so good is we catch a break in the flow of LP and the strength of the jet to the north. This break gives the HP a chance to build strongly north and then NE. The Atlantic profile on the Control immediately doesn't look as encouraging and the outcome isn't the transition to an HLB we see on the OP but an MLB centred over the British Isles. Yes, it would draw in a chilly NE flow to the south east corner but there's little for snow fans in that. All I would say at this time is the timing of the possibility of a cold outbreak in February looks about right but so much needs to drop right. Many UK cold spells have started with the Azores HP transitioning to Scandinavia and the OP route to do that has happened before so it may happen again. The degree of spread across the GEFS even at T+240 is indicative of a model pattern struggling with the lack of clear signals. Many GEFS members are HP dominated though the position and orientation of the HP vary considerably. One or two members (and this wasn't the case yesterday) have pulled the HP further west and dropped the trough right down over the British Isles (this was hinted at in far FI on the 00Z OP yesterday). The big area of difference is off the SE of Greenland. Think about it - put an HP there or an LP there and the barometric pressure over southern Britain might be similar but that's all that would be similar. Those Downbeat Dereks and Damians who were hailing the end of winter last night might be right but I simply don't see that this morning unless GEM has nailed this. ECM continues to tantalise at T+240 but the path remains unclear so it's GFS this morning which dangles the carrot and IF the OP verified this morning into FI it would be a carrot to savour for winter weather fans.

Morning all Another day, another named storm it would appear but it did look as though we were heading into a more settled spell with the change in the month so where are we this morning ? ECM 00Z at T+240 (February 3rd): A cracking chart for cold and snow fans to start the day. Rain and snow in abundance to the east and south east and the Azores HP trying to ridge north into Greenland. I expect the T+264 chart wouldn't show that but it's a fine chart for fans of winter. GEM 00Z OP at the same time: Very different as might be expected. In comparison to yesterday's GEM, a shade more amplified but with a 960MB LP off the Norwegian coast, a strong cold NW'ly flow across the British Isles with the best of any dry weather to the south west and possibly blizzard conditions in any snow showers to Scottish hills and mountains. GEM has a much stronger Atlantic profile than ECM so no prospect of any HLB but note the small LP in mid-Atlantic and the sense each new HP cell coming off the CONUS is angled further north than its predecessor. It's not a chart without interest or the "p" word. GFS 00Z OP at the same time: Strong HP just to the SW of the British Isles and fairly benign conditions for most on a mild W or WSW'ly airflow. The Atlantic profile, while not as vigorous as GEM, means there is enough strength in the northern arm of the jet to prevent the HP ridging N or NE at this time. Further into FI, the PV becomes very powerful trapping a very large pool of very cold air and creating cyclogenesis in the north Atlantic keeping a strong WSW'ly airflow going and the British Isles in mild and fairly benign conditions. GFS 00Z Control at the same time: Not too dissimilar to the OP at this stage but further into FI the HP staggers across the meridian and ends up over or just to the east of the British Isles with another attempt to ridge into Greenland under way at T+384. Looking at the GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 I'd say the OP and Control are fairly representative. The theme is MLB but the exact location and orientation are far from resolved. A position to the west or SW of the British Isles looks favoured this morning but other options are on the table. Further on, as you'd expect, the spread becomes considerable but that's not to say there aren't a lot of cold options on the table and, I'd argue, more cold than mild at this stage. In summary. the three main models at T+240 all have their own evolutions which suggests huge buckets of uncertainty. ECM is dramatic for cold fans and perhaps less lonely than it was yesterday. GEM has amplified slightly while GFS loves its HP cells in the SW approaches. I suspect after the short colder blip on Thursday we'll see a return of milder conditions for a few days but the evolution from early next week remains far from clear.

The GFS 06Z OP is, if anything, even more anticyclonic in FI. Barometer-breakingly high pressure more or less over the British Isles but some interesting charts and things to note on the periphery: T+240: It doesn't happen this time but it's an indication that a Scandinavian HP isn't off the table. Here's T+336: The thing to note here is the LP which moves out of Africa toward Greece. This brings some wretched weather for SE Europe but helps "hold up" HP further NW. If we want MLB as far north as possible we need this storm or something similar to lower heights in the Mediterranean basin.

Morning all A chance for me to take a look at the morning's medium term output to see where the early days of Febraury might find us. So, it's the charts for T+240 which means Friday February 2nd so starting for a change with ECM: A dramatic opening shot from the European model. A cold NE'ly though not remarkably so (850s between -4 and -8) and likely to be unsettled particularly to the south and east with rain or snow but fine to the far north west. Basically, the Azores HP tilts toward Greenland allowing a small but complex LP to move down from the NW into Europe. Have to say this looks a classic toppler. GEM 00Z OP at the same time: Very different. A much flatter pattern with less amplification. The Azores HP is ridging into Europe rather than to the north so much milder and drier conditions for the south while the north remains unsettled under a more Atlantic dominance. GFS 00Z OP at the same time: Different again. The Azores HP has moved much closer to the British isles and while there is a cool NW'ly breeze down the east coast, for most it would be dry and settled albeit with frost at night under clear skies. Further into FI and strong Azores HP cells (1045 MB and above) do battle with a powerful jet firing deep LP out of eastern Canada. Unsettled and often very windy or stormy but mild in the south. Colder in the north with snow to altitude likely. GFS 00Z Control at the same time: The Control has the HP in charge and sat right over the British Isles but its evolution isn't dissimilar to the OP in terms of the struggle between the HP cells and the jet stream. Looking at the GEFS at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 The main theme here is anticyclonic. Many members have HP close to or over the BritIsh Isles, two or three get the HP further north or NE to advect some colder air over the British Isles but it's MLB day to this observer so little for snow fans but for fans of cold always the hope of some inversion leading to frosty and foggy conditions. MY take on the morning's mid range output is we have a very wide range of evolutions but all are dependent on the behaviour of the HP cells which form over the Midwest and head SE into the Atlantic and basically re-enforce the Azores HP cell. ECM offers a tantalising vision for cold.snow fans but I'm far from convinced. GEM plays the flat game and could be right but the signal for HP dominance at this time of year is often right - February is a dry month - so GFS looks the form horse but whether the HP can get far enough north in the face of a strong jet is still open to question. MLB looks more likely than HLB to this observer at this timer but fans of cold know the HP doesn't have to be too far north to draw in a colder continental flow.

Morning all A chance for me to take a medium term look at where the models are showing. Starting with ECM 00Z at T+240 (January 29th): The Azores HP (or a version of it) has finally got as far NE as NW France but the orientation brings mild or very mild TM air over us. Hard to think there wouldn't be a lot of cloud in that airflow but at 1040MB there's a possibility we might see some breaks to the lee of high ground so sunny and very mild days and foggy nights for a few but otherwise benign and largely settled. Worth noting the Atlantic seems pretty quiet at this time. GEM 00Z OP at T+240: A lot of similarities with ECM - the Atlantic a little stronger and the HP a little weaker and a little further south but for the British Isles the mild or very mild SW'ly airstream continues. GFS 00Z OP at T+240: Slightly different. The Atlantic is, as is often the case with GFS, much stronger with a very deep and vigorous LP to the east of the Faeroes. Further into FI, the European HP tries to build NE into Scandinavia but it's a struggle against the northern arm of the jet and at T+384 is centred over Poland and the Baltics and, as we all too often see, the very cold air is heading into the Balkans (-12 and -16 850s) while for the British Isles it would became colder especially over the SE under light winds with fog and frost possibly becoming more prevalent. GFS 00Z Control at T+240: Not too far removed from the OP in all honesty. The HP is centred over eastern Europe and not oriented well but there's the faintest hint of a continental drift for SE parts. Into further FI and the Control sets up a new HP over the British Isles before it declines SE into Europe. So to the GEFS Ensemble panel at T+240: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 There's a strong anticyclonic theme in the GEFS not I think reflected in the OP. I'd say a majority have HP in control and a significant minority have that HP to the north, north east or east of the British Isles with one or two having the MLB centred over the British Isles. I'd say those showing outright Atlantic dominance are in the minority this morning. To summarise, the transition to a much milder pattern is set but any spell of unsettled conditions is looking of short duration with strong signals for a pressure rise from the SW through the end of next week. January looks to end and February to start on an anticyclonic note but where the HP will end up is wide open at this time. It's also worth noting the changes in the Polar profile.

Afternoon all After the interest of the next 48-72 hours it looks increasingly as though we will be entering a milder Atlantic dominated phase lasting 10-14 days. With pressure high to the south quantities of rain for southern areas look low after the weekend . Doubtless many will be disheartened, downbeat and dejected. Perhaps but I'd point out we're barely half way through winter and there's the small matter of February to come. I'd also point out the route to very cold often starts from very mild so a spell of milder weather may not be the curse it seems. I'd also mention that March is perfectly capable of delivering snow even for lowland areas.

Afternoon all Some early comment on the 12Z suite. ICON shows a milder spell for the south into next week with 2m temperatures rising into the teens from Monday until a sharp cool down on Thursday. More of a blink and you'll miss it affair further north. Looks like the 06Z GFS Control to be honest. GFS OP much the same - a new storm forming to the south of Greenland tomorrow and Saturday meanders toward Iceland before heading east early in the week and deepening. Looks as though it will pass well to the north of the British Isles - over the Faeroes perhaps - while the Azores HP moves in to Southern France bringing a spell of mild SW'ly winds (in truth not really had a blowtorch spell this winter so far). GEM develops a large European HP area into early next week with the Atlantic LP much weaker than GFS and displaced further west so once again mild or very mild across southern areas through next Tuesday. GFS 12Z OP Northern Hemisphere Profile for T+144: UKMO 12Z NH Profile at the same time:

Just to review the precipitation numbers over the next week: The NW facing coasts and hills are set to take a pounding with some worrying rainfall (snowfall) numbers yet much less further east and south.

Afternoon all An interesting week coming it would seem with fresh to strong WNW'ly winds and frequent showers, no doubt primarily of rain for the south and lower ground but the possibility of snow to lower levels in the north and to altitude almost anywhere with the "fun and games" of a vigorous secondary LP crossing the south on Wednesday/Thursday bringing a potentially disruptive spell of rain and strong winds. By the end of the week the trough is moving out to the east and south east and a northerly brings in some very cold air with the likelihood of a couple of frigid nights and especially where any snow has remained. Where do we go from there ? ECM 12Z OP at T+240: If you want a definition of a messy chart, there you go. The Atlantic looks weak, the Azores HP is suppressed well to the south but there's little evidence of northern blocking either. GEM 00Z OP at T+240: The Atlantic wins through albeit without much power. The differences in NH profile with ECM are considerable so no surprise it's a different evolution. GFS 06Z OP at T+240: The Atlantic in charge to a degree but still some hint of a negative tilt to the trough so you'd think the LP would head SE rather than NE. GFS 06Z Control at T+240: Takes this to another extent as the LP deepens sharply and slides SE into France but the HP builds back strongly behind it. Picking the bones out of the METO 30-day summary there's an argument for an MLB to set up near the British isles and then sinking south allowing milder Atlantic air to return into February. The GEFS show the Azores HP becoming more influential with time but its orientation and position still very much up for grabs. It COULD ridge in strongly toward the UK sending the jet back north but it could inflate in the mid Atlantic keeping the N'ly or NW/'ly flow going. Nowhere near resolved yet.

The question from that becomes what any rise in pressure would look like and where any resulting HP would sit and be oriented. The 12Z GEFS out in far FI are a mixed bunch as you would expect but I would value a pretty large cluster try to raise pressure across the British Isles. Some have quoted the EC46 as a source for the Azores building in argument but the Control for instance builds pressure from the NE while another option might be to see pressure build from both north and south with an MLB set up close to or over the British Isles. I have no idea and the models are playing with all kinds of solutions at this point. Just had a look at the GEM Ensembles however and a strong cluster sending the Azores HP NE toward the south west approaches with the blow torch hot (as it were) on its heels.

Evening all Not expecting any lying snow in lowland East London but will I see any falling snow ? Perhaps but I do think I will see plenty of rain and perhaps some hail and sleet as next week goes on. Overall precipitation quantities of interest: A lot of rain (and presumably snow) to western and north western areas but much less further east. Where do we go from there ? ECM 12Z OP at T+240: GFS 12Z OP at T+240: GEM 12Z OP at T+240: To be honest, all these and the GEFS at the same time tell me there are no strong signals as yet for the evolution into the last third of January. The GFS 00Z and 12Z Control both offered something of interest but until the exit of the trough next week has been sorted out it's going to be hard to have any confidence in the evolution beyond that point.

Indeed, the charts for January 15th have been consistent for days in general terms: GFS 12Z OP on January 5th for T+240: Tonight: GEM at the same time: Tonight: Yes. some subtle changes in detail as expected but the general thrust for the British Isles remarkably accurate at longish range.

Moving on from my birthday, how are we looking further down the line ? GFS 12 Z OP at T+240: A cold or very cold day with temperatures close to freezing over higher ground and in the north. Further wintry weather likely though fading as the main LP moves away over Europe. A sharp frost from a transient ridge before the next LP approaches. ECM 12Z at T+240: More progressive than GFS. The ridge has arrived and it's a fine cold day for all but winds already backing SW over Ireland. Worth comparing the NH profiles - the GFS has a very strong HP over NW Russia and the obvious question is whether this can build toward the Pole. GEM 12Z OP at T+240: An interesting blend. Yes, we have the transient ridge but a nose of LP heading in - will it go SE into France or across the British Isles. There's warmer air wrapped in it which looks to move up against some colder air still over the British Isles. Very interesting to see what happens one the LP and trough drop into Europe at the end of the next week and certainly very far from any resolution.

Evening all Birthday watch for tonight - down to T+96 so you'd expect broad agreement: UKMO: ECM: GFS OP: GEM: NAVGEM: JMA: Still some nuances to be resolved - the NW of earlier days has become a WNW or even a W'ly with consequently warmer uppers. The Azores HP is perhaps closer and more influential and the delayed collapse of the Scandinavian HP into Europe has perhaps left less option for a SE'ly move of the LP than was the case a few days ago.

Today's update from METO: https://www.metoffice.gov.uk/public/weather/forecast/gcpvj0v07#?date=2018-01-10 Fairly ambiguous in the extended forecast. Suspect there's no clear signal for anything as yet later in the month.

Afternoon all It's all gone quiet... The 06Z GEFS are an interesting bunch: The majority (I would contend) weaken or lift the PV out of Canada completely by T+288. Here's Control (which oddly enough retains a chunk of PV in its usual habitat): So it begins - first hints in the ENS followed by appearances in the OP and some stellar output at T+168 and T+144 only for the whole thing to be watered down from then. Maybe, maybe not.

Morning all Birthday watch got delayed last night which may have been no bad thing. We're well into high-res for next Monday's chart so you'd think the models would be firming up in agreement: So let's see: GFS 06Z OP for T+126: Control at the same time: GEM 00Z OP at T+132: NAVGEM 06Z at T+126: Finally, ICON 00Z at T+126: ICON stands out as a slight exception (though ECM isn't far removed from it) otherwise we're pretty much in agreement. A vigorous extremely powerful LP storm develops the day before off the south east coast of Greenland as a lobe of PV energy is ejected SE and this deepens sharply to 935-945MB before starting to move ESE for most - at present, most models are taking the storm as a weakening feature ESE into Europe though there are a number of complex iterations within that. The resilient HP block over Scandinavia has "slowed down" this development - the models from five days ago were showing the LP across the British Isles on the 15th but that has been put back 2-3 days because, I would argue, the block has intervened. What it does show for model forecasting purposes, is that, irrespective of whether the block directly impacts the UK weather, it has considerable upstream implications if it proves to be more resilient. Here's a thought - the California storm modelled on the GFS 00Z OP at T+54 (so Saturday's output): The same storm four days earlier (00Z OP output for 3/1/18 at T+150) Still out in the Pacific - I don't know but has the behaviour of the block and the weakness of the Atlantic over here had ramifications in terms of the progress of the Pacific storm systems or is there no causal relationship at all ?

Evening all That time of day again - yes, birthday watch and we're down to T+168: Tonight's charts from the respective 12Z OPs: ECM: GEM: GFS: JMA: NAVGEM: Broad agreement on the generalities but disagreement on the specifics. The movement NW to SE of the trough looks settled but the core of LP remains to be resolved - it moves in to be just west of the British isles by next Monday before moving in and over us for early in the week. Rain or showers for all would be the forecast to this observer but perhaps not too windy.