TEITS

The ideal scenario would be the slider LP bringing snow to those in the W followed by biting E,lys bringing snow showers into the E. That way everyone is happy, or nearly everyone! Have to laugh though. Back in late Dec, early Jan I was suggesting it would turn colder from mid Jan especially into the 3rd week. I then apologised around a week ago for being wrong and even suggested I should stick to my other hobby of watercolour painting. Obviously my reverse psychology worked!

Just a quickie as I have little time. I have read a few comments saying "it looks dry". These exact same comments were said during Dec 2009,2010. You will always find surprise snowfall turns up and is never possible to predict at this timeframe. Damn good 06Z. http://www.wetterzentrale.de/pics/Rtavn2281.gif Predicted surface temps remind me of 1981!

Overall im delighted with the output this morning. Some potentially bitterly cold min temps being possible followed by ice days and then potential for snowfalls. Alot to sort out though with regards to details especially around Tues/Wed next week as LP slides SE. What will cause issues here is how far E this LP tracks before tracking SE and the consequence of this is the positioning of the HP to our N/NE. This will impact who recieves any snowfall and how marginal it will be. The GFSP is probably my favourite this morning. The LP tracks across the W followed by a nice E,ly. http://www.wetterzentrale.de/pics/Rpgfs2071.gif So overall excellent output but this time I refuse to look towards when the cold spell might end. Considering the crap winter so far for my location im just going to enjoy this weekend and early next week.

What I love about the current output is the period this is occurring. I cannot tell you how many times I have seen a fantastic E,ly being progged by the models at +240 and watching this implode at +96.

Just a word of caution for those in the W with regards to a possible slider LP. What has basically happened since I noted the potential since yesterday morning is the models ,especially GFS, are trending towards more significant high pressure to our N with the slider LP backing further W. So with this trend developing what could happen is the Low pressure misses the UK as it tracks W of the UK on a SE,ly trajectory. The positive of this is a stronger more sustained colder spell beginning with a N,ly before veering to a NE/E,ly.

The models this morning remind me why it is such great fun being having meterology as a hobby. Not only do we have such varied weather but the way it is prone to change. Looking at this mornings models I am going to be concentrating on 3 seperate aspects in the following order. 1. Make sure the trend towards slider LPs, rise in pressure to our N/NE continues in the output. 2. Once 1 has been established concentrate on the tracks of these slider LPs.. 3. After 2 I shall be looking to see whether a classic E,ly will develop i.e very cold uppers, snow showers. The ECM hints at this but this mornings UKMO +144 is probably the best output for this because as the trough sinks a strong E/NE,ly flow would develop.

Well, well, well. What is showing on the 18Z GFS/P is exactly what I described above. Does not mean it will happen but its nice to see an upgrade for us coldies.

I still wouldn't rule out a massive shift in the output in the reliable timeframe. Note the LP on the southern tip of Greenland. http://www.wetterzentrale.de/pics/Rtavn1441.gif What could well develop is instead of the normal W-E movement we see trough distruption with this going SE to the UK bringing a risk of snow. As this occurs do not rule out a weak ridge of HP developing to the N of the UK bringing an E,ly flow. Seen this happen before and could again!

So despite me saying a few days ago that the GEM had lost the plot and gone mad there are hints from the 18Z that it wasn't so bonkers after all. The 18Z reminds me a little of what occurred during Jan 2013. What I mean by this is the models back away from the normal W-E movement of LP and we see sliders tracking SE. When this occurs you can sometimes see a weak area of high pressure develop to our N. Remember I said a while ago that you don't need mega high pressure to our N to bring cold to the UK! Whilst this could be a blip or a new trend towards a colder, snowier outlook!

The reality is Mushy many members like extremes whether that is cold/snow, heatwaves, thunderstorms, severe gales via storms etc. Considering the lack of snow these past couple of winters, many members are hardly going to get excited mild, unsettled weather. Anyway in my opinion many of the posts this winter in the model discussion thread have been negative due to the lack of cold synoptics and i've rarely seen anyone mention 1962/63 is about to be repeated. Sometimes bitterly cold F.I charts are highlighted but there is nothing wrong with this as it is still on topic and only highlighting a model run. What causes the most problems in the thread is when someone says "no sign of cold/snow" when really they are referring to their location and not taking into account other members locations. The current pattern is a good example because whereas I have little chance of seeing snow this isn't the case for those in the N.

Thanks Paul for starting this thread but personally I like the model discussion thread as it currently is.

Overall im disappointed in the output with regards to the medium/longer range. Once again the Met O appear to be spot on and reminds me that when we seek a significant cold spell you need this forecasted in the Met O 30 day forecast. I have been wrong on numerous occasions so far this winter and this is because I have believed the GFS F.I charts. Reason for this is sheer desperation following a rubbish winter last year and so far this year. Apologies if this appears off topic but the gist of what I am saying is the outlook appears to be as suggested by the Met O i.e unsettled with alternating milder/colder spells. I would ignore any GFS F.I eye candy which is what I should of done! I also have to say well done to John Holmes because like the Met O he has also been spot on. I might be a hard core ramper who always predicts bitter E,lys but I am always willing to admit when I get it wrong and also praise those who are correct. I think I shall stick to my other hobby of watercolour painting rather than forecasting lol.

Looking at next wed/thurs storm and the evidence suggests it will drop to around 955mb. The track suggests N Scotland so if I was living in Glasgow/Edinburgh I would be getting rather nervous! http://max.nwstatic.co.uk/ensimages/ens.20150110/00/prmslAberdeenshire.png Beyond the storm and the GEM yet again has lost the plot and gone mad by showing an E,ly! http://modeles.meteociel.fr/modeles/gem/runs/2015011000/gem-0-222.png?00 Now I have known the GEM to be correct in these situations and this occurred I believe in Jan 2013. However even I believe the above chart is unlikely to be correct.

I commented yesterday about the exciting trend im seeing with regards to the PV and I shall explain further. I note BA has also commented on this. Take a look at where we currently are and im going to use the control run as an example. http://modeles.meteociel.fr/modeles/gens/run/gensnh-0-1-0.png?0 Core of the vortex well and truly located across Greenland hence the stormy pattern. Note at +168 a change occurs with a lobe W of Greenland and another across Russia and a deep LP across the UK. http://modeles.meteociel.fr/modeles/gens/runs/2015010900/gensnh-0-1-168.png Now at +276 the PV is far weaker and less organised. http://modeles.meteociel.fr/modeles/gens/runs/2015010900/gensnh-0-1-276.png At +384 the PV becomes stretched from Asia to Siberia. http://modeles.meteociel.fr/modeles/gens/run/gensnh-0-1-384.png?0 So what this means to me is this. After the potential N,ly spell around mid Jan I can see a more prolonged cold spell developing. This is because in my opinion the PV will not be centred across Greenland and instead the dominant vortex shall be across Siberia/Asia. The result of this will be HLB developing bringing a much colder spell of weather especially for the last week of Jan into Feb.

Just a quickie as I don't have much time. Looking at the model output I would be staggered if the Met O outlook was correct. The change towards a colder 2nd half of Jan is gathering pace and an even colder last week of Jan looks on the cards. Despite the varying GFS runs they are all pointing towards a colder trend. Very excited at todays output so far. Just add its the trend with regards to the PV that is exciting me and shall explain later.

The chart below is the main interest for me and in my opinion the ECM would go the same way. http://www.wetterzentrale.de/pics/Rtavn2761.gif I mentioned this yesterday about low pressure taking a SE,ly track with pressure rising behind bringing an E,ly.

Well been a few days since I last posted and today I have mixed feelings with regards to the output. Firstly the signs towards a colder 2nd half of Jan continue. However my mixed feelings are that from around mid Jan it appears a colder NW,ly could develop which could bring snow showers for NW England/Scotland/Wales. My negative feelings towards this is it looks as though it will be via HP to the W of the UK rather than significant blocking towards the NW of the UK. On a positive thereafter the GFS and some GEFS members want to track a LP SE with pressure rising behind this to the N/NE of the UK bringing a possible E,ly. So in summary it looks likely to turn colder mid month but this doesn't appear to be a prolonged freeze. At the moment we shall have to remain patient but I am encouraged with the trend especially as we head towards the last week of Jan.

I agree with CH. My own thoughts with regards to LRF is at the moment far too many variables which are not fully understood make long range forecasting very challenging, in addition you then have the problem of figuring out how they interact with each other. So what is the option do you give up or carry on? Well you won't find the solution by simply giving up which is why LRF must carry on. I will add even if the Net Weather & Steve M forecast are completely wrong I am still very grateful to the effort they put in and will look forward to next winters LRF. At least we do not have to pay for these forecasts unlike some who predict 1963 winters every year and have the cheek to charge for them!!

Looking at the SLP at various locations and this potential storm is rather worrying. Devon http://max.nwstatic.co.uk/ensimages/ens.20150106/06/prmslDevon.png Aberdeen! http://max.nwstatic.co.uk/ensimages/ens.20150106/06/prmslAberdeenshire.png Not only does it have support but some have an even deeper LP.

Still plenty of time for this winter to be fondly remembered as a classic. Some may think im mad saying this but like I said a few days ago, if for example the last week of Jan turns very cold with heavy snowfalls and this continues for the first week of Feb then we should really be satisfied with this. When I think back to cold spells in my childhood the winters did not consist of constant blizzards. I think we need to accept the climate we live in. I also think the other reason for such recent negative posts is a combination of last winter and our current one. I remember the harsh cold spell of 1981 which was far colder, more snowfall than Dec 2010 in Peterborough, the blizzards of 78/79, the biting E,lys of the late 80s and the Feb 91 E,ly. Yet none of these cold spells were as memorable as Jan 1987 and yet this winter was largely mild except the freak 7 day E,ly.. I still remember to this day the dreadful experience of walking to school in a blinding blizzard when max temps were -7C and this wasn't taking the wind chill into account. I also vivdly remember how heavy and constant the snow was. So in other words plenty of time left yet!

One pattern which many haven't noticed over the past 4 or 5 days is how often the GFS & GEFS control run are always colder than the mean. As a consequence the SLP mean in Iceland is lower than the GFS Ops/Control. When this happens continuously then its worth taking note rather than being the odd outlier. So my view remains the same it will turn colder from mid Jan onwards. The real tricky bit is this could range from a brief cold snap followed by mild W,lys. A classic N/NE,ly cold spell via blocking to our NW. Another scenario is a brief N,ly followed by blocking developing over Scandinavia bringing an E,ly. Note some of the GEFS ensembles are colder in my location than Scotland. This can only occur via an E,ly! http://max.nwstatic.co.uk/ensimages/ens.20150105/06/t850Cambridgeshire.png Note GFS/Control reach 1020mb over Iceland, 1040mb Oslo http://max.nwstatic.co.uk/ensimages/ens.20150105/06/prmslReyjavic.png http://max.nwstatic.co.uk/ensimages/ens.20150105/06/prmslOslo.png Problem is this is just out of the range of the ECM. So at the moment from an unbiased point of view of the models there is enough evidence to suggest it may turn colder but not enough evidence to ramp away at a potential big freeze.

Except when mild SW,lys are showing. Only kidding mate.

15th Jan is around the period of change which is 11 days away. This date has consistently been suggested by the GFS/GEFS.

I read a post this morning saying there was no sign of a change in the 10-15 day period based on the anomalies. My reply to this would be you need to look at all the available data because in my opinion that isn't the case. The trend towards a change occurring from mid Jan appeared many days ago and since then has continued. Whilst the GFS Ops have obviously swung between just a brief colder spell to a more prolonged cold spell, the pattern change is apparent in the GEFS ensembles. The Aberdeen ensembles show the alternating airmasses between low pressure systems but from mid Jan this becomes more sustained at -5C. http://max.nwstatic.co.uk/ensimages/ens.20150104/06/t850Aberdeenshire.png The best example of this coming pattern change is the Iceland SLP mean. http://max.nwstatic.co.uk/ensimages/ens.20150104/06/prmslReyjavic.png This is increasing all the while. The GFS Ops & GEFS control were a few days ago much higher than the mean but slowly other GEFS members are coming on board hence why the mean is increasing. So my summary remains the same as the 29th Dec. From mid Jan a colder spell will develop via N/NE,lys. However how prolonged and cold remains uncertain. Initially the N/NE,ly will be via HP to the W of the UK. However this could develop into more sustained blocking to the N/NW/NE of the UK bringing a prolonged cold spell. On the other hand this blocking does not develop and after a few days of cold N,lys the block to our W is eventually toppled with a return to milder W,lys. At this stage my instincts favour the sustained blocking scenario and a prolonged cold spell!

From a forecasting perspective I find charts at +312 more rewarding because of the greater challenge. Where is the fun in forecasting general trends at say +144 when generally speaking the models have a good handle at this time frame. I do think the art of forecasting is being lost by the over reliance on computers. Whilst some are wary of recent GFS runs I am not and remain confident of the change I highlighted earlier.