Leaderboard

I'm not surprised at the increased interest that the 6z shows as I hinted might happen in my morning report. Let's hope it's the start of something that's expanded upon later.

Indeed - and likewise beyond. Through the first half of February, GloSea continues to stick to it's recent tune of an initially SW'ly flow then veering more W/NW'ly during first half of the month. The net result is a signal for colder than average conditions to develop as the month progresses. The UKMO Seasonal Consensus meeting has been taking place today in Exeter, so we hope to hear more regarding their judgement for next month later this evening.

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 09:00 ON WEDNESDAY JAN 20TH 2016 THE CURRENT GENERAL SITUATION A ridge of High pressure lying across the UK today will move away SE tomorrow as freshening Southerly winds and troughs of Low pressure move into the SW of Britain tomorrow moving slowly NE. http://www.wetterzentrale.de/pics/Rtavn001.gif CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the British Isles is around 2000ft apart from the far SW of England where the level is nearer 4000ft today rising to in excess of 5000ft here tomorrow. Snowfall is unlikely today. http://www.snow-forecast.com/maps/dynamic/uk http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow.gif MODELS-2 WEEK HEADLINE Becoming milder and more changeable with rain at times from later this week especially towards the North and West. Mostly dry at times in the SE. THE GFS JET STREAM FORECAST The Jet Stream currently weak across the Atlantic will ramp up somewhat and move East across the UK for a few days. Thereafter the prediction for it to locate well to the Northwest of the UK remains with High pressure close to the UK later keeping it well away from UK shores. http://www.netweather.tv/index.cgi?action=jetstream GFS OPERATIONAL The GFS Operational Run today is largely focused on dry and fine conditions under High pressure to the East and SE through the run. There is a couple of milder and more unsettled periods shown within the first week of the run when some rain any affect all for a time particularly this Friday and maybe again towards the middle of next week. Other than that this run shows any rain more focused towards the NW with a lot of dry, bright and possibly rather cold conditions with frost at night the more likely weather for many through the period. GFS CONTROL RUN The theme of the Control Run today also shows quite a lot of anticyclonic weather especially for England and Wales. A milder spell is likely following a spell of rain over the weekend and this run too shows the chance of another spell of rain towards the middle of next week which is followed by a rise of pressure across the South which then extends to Europe and sets up a trend towards rather cold weather with frost and fog returning by night and more unsettled conditions threatening the UK again at the end of the run as Low pressure moves into a cold block returned across much of Europe by that time. http://www.wetterzentrale.de/pics/Rtavn1441.gif http://www.wetterzentrale.de/pics/Rtavn3841.gif http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=144&mode=0&carte=0 http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=384&mode=0&carte=0 GFS ENSEMBLE DATA The theme of the GFS Ensemble Clusters this morning indicate a 65% pack with High pressure either to the SW or over the British Isles itself offering fine weather with some overnight frosts and fog. The remaining 35% of members show milder West or SW winds and rain at times in association with Low pressure to the North of Britain. http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD= UKMO The UKMO model this morning shows an altogether milder period coming up as SW winds and occasional troughs of Low pressure move NE across the UK from Friday with rain at times for all with the heaviest and most persistent falls across the North and West but with brighter mild spells as well especially across the South and East. http://www.wetterzentrale.de/pics/Rukm1441.gif THE FAX CHARTS The Fax Charts today is quite representative of the raw data as the winds turn SW for all and after a series of frontal troughs bring milder air to all over the weekend. High pressure lies to the SE with a warm front moving back NE across the UK bringing further mild and cloudy weather with rain or drizzle at times especially across the North and West http://www.weathercharts.org/ukmomslp.htm#t120 GEM GEM this morning shows milder air moving across the UK this Friday with some rain for all followed by several days of rather changeable weather with some rain in the North and West. With time though High pressure never far away to the SE realigns later as a cold puddle of air moves West over Europe and threatens the UK again with colder air later with some frost returning especially towards the South and East while the NW probably maintains the dampest and mildest weather. http://www.wetterzentrale.de/pics/Rgem2401.gif NAVGEM NAVGEM today prefers to fly the mild flag today as once the rain bearing trough of Friday introduces less cold air the rest of the period is shown to maintain SW winds for all with further rain at times and strong winds too as we reach the middle of next week as a more vigorous Low pressure area is shown to move up from the SW towards the SW approaches. http://www.wetterzentrale.de/pics/Rnvg1681.gif ECM ECM today shows the breakdown on Friday with a spell of rain for all ushering in milder Atlantic SW'lies. Thereafter pressure is shown to remain High to the SE and Low to the NW with the influence of Low pressure maintaining milder Atlantic winds with rain at times there while High pressure often very close to Southern Britain maintaining a lot of fine weather there with nearer to average temperatures at times and probably a return of some night frosts at times later. http://www.wetterzentrale.de/pics/Recm2401.gif ECM 10 DAY MEAN The 10 day mean chart has good agreement that pressure is likely to be Low near Southern Greenland while High pressure lies across the Azores in 10 days. Pressure patterns over Europe though look very indeterminate with a variety of options shown within members which could have implications for less mild conditions across the far SE of the UK later. http://www.wetterzentrale.de/pics/Reem2401.gif NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The models show a classic NW/SE split in trend this morning with varying degrees of bias towards a dominance of influence of High pressure over Europe again this morning. 31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECM show at 24 hours ECM ahead at 99.6 pts with GFS edging ahead of UKMO at at 99.5 pts to UKMO's 99.4 pts. At 3 days ECM is leading with 97.6 pts to UKMO's 96.8 pts while GFS lags behind at 96.4 pts. At 5 days ECM leads with 89.9 pts to UKMO at 88.0 pts then GFS at 87.6 pts. Then at 8 Days ECM still leads at 65.7 pts over GFS's 65.4 pts. Finally at Day 10 ECM is ahead of GFS at 50.3 pts to 47.6 pts respectively. http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day1_PMSL_MSL_G2NHX.png http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.png MY THOUGHTS With temperatures not far off -8C outside my window as I type it is hard to imagine that in a couple of days time temperatures will be some 15C warmer but such as Winter in the UK this is the most likely outcome shown within the models again today. The current cold High pressure across the UK will slide away East over the next 24 hours as troughs of Low pressure move up from the SW to reach the SW later tomorrow and all areas on Friday. All areas will see a spell of rain followed by much milder SW winds and some bright weather over the weekend. There will be some further rain especially across the West and North though with the main difficulty this morning in the detail surrounding this milder phase of weather. Some output notably those from this side of the Atlantic show quite unsettled conditions early next week and possibly longer with rain at times for all and temperatures responding to near or a little above average at times. However, this is not the blanket approach by all models. There remains a cold block across Europe which although recedes East over the coming three or four days will remain poised towards Russia and the American models do acknowledge this and coupled with High pressure which never lies far away to the SE and East could come back from the East later as High pressure rebuilds across a more Northerly latitude in the second week. It may be just natural variability between model runs and this theme may disappear in the next runs but my gut feeling is that the milder weather to come will not be like the spell in December with High pressure playing a much more dominant role aided by a weaker Jet Stream than back then and if it builds sufficiently North over Europe or even into Southern Britain it wouldn't take much to throw a totally different reflection on the weather at the surface than that currently indicated. I do believe that we are not moving into a spell of prolonged mildness but rather a period of changeable weather with a slow theme to drift back into dry and anticyclonic weather with frosts returning within a week or so. So having nailed my colours to the mast lets hope that I am right and that trends continue to develop towards a colder evolution in the rest of the runs today and tomorrow. Next Update Thursday January 21st 2016 from 09:00

GLOSEA5 sounds to me as if it's trying the 'west-based NAO moving steadily east' theme. Anyway, in light of that somewhat tasty GFS 06z operational, I decided to compile the GEFS outlooks for the AAM/GWO from the 15th (in red), 18th (in blue) and 20th (in green) and see how that looks: Aha! Big changes afoot, with the much greater neg. dM/Dt in phase 8 a reflection of the expected negative MT event being picked up on, and the signs of a move toward 4/5 the beginnings of the response to that MT event that should actually take the GWO back to phase 5 and may not even visit the COD along the way, based on how large the negative AAM bias in the GEFS model has been on the approach to the previous two 6/5/6/7 orbits. Notice also that the amount of AAM drop in the short term - literally the next few days - has been reduced a little with time. Given that falling AAM corresponds to additions of westerly momentum to our latitudes and so a boost to the polar jet (as Tamara mentioned in her excellent post last night), these slight reductions may be what's allowing the splitting jet outcome to gain a little more support in the GEFS. There may be a similar trend going on with ECM, but not yet enough to make a notable difference. I'd say this is a classic case of 'if trends continue...!'. The question over the rest of Jan has long been whether the drop in AAM will be small enough to allow enough amplification to overcome the flatter pattern encouraged by the period of more neutral/positive AO that leads us up to the SSW (and is important for the SSW to have significant impacts on the tropospheric vortex). Evens like 1991 do show us that such a thing is entirely achievable with a bit of luck. Or maybe a lot of luck. This is Blighty, after all

Well - was the TS forecast unwise? Is winter really over now? Can IF get any more cryptic? Where has GP gone.... and just what on earth is happening in the strat, over in the pacific and to the modelling of the GWO for the next 2 weeks? All models are picking up increased amplification towards the middle/end of next week, and the GFS links that with the semi-permanent high of the current winter season to build a fairly impressive Scandy block. As the trop vortex then becomes stretched (coordinated impact of trop and strat factors coming together?) we see a signal for retrogression of those heights towards Greenland. GFS op today would bring proper snowfall to the south of England on 1st Feb. ECM meanwhile turns a fairly amplified atlantic at 96h to a flat high powered westerly by 144 as the azores high strengthens and extends across mainland Europe. Yuck. Where does the trail truly lead? Hard to say - but certainly not inevitably to a Euro high. There is a strong wave 1 assault on the strat visible at the end of next week, and confusion once again in the modelling of the MJO (GFS more coherent, ECM all over the place....). The crunch for me is that the modelling of the GWO currently has it falling fairly fast into a low orbit phase 1/2 (cant seem to post the chart? - but take it from me - it is.) This runs counter to the prediction from GP that saw a Western Pacific trough and upstream ridge as being a good signal for maintaining the GWO in a decent orbit phase 7/8. So - what are we to think? Ha - I suspect we genuinely dont know. I'm sure Stewart will post again with his take on the GWO forecast at some stage soon... and perhaps he over estimated the robustness of the high amplitude pattern. Or perhaps the models havent seen it yet properly and once the pacific trough/ridge scenario kicks in over the weekend we will see a sudden model shift as they pick up the signal for a sustained GWO impact. Overall both op and mean modelling for next week has been fairly underwhelming the last few days, but on its own this does not mean the game is up for winter. There are, quite simply, too many factors pointing in slightly different directions to be at all confident of what the pattern will be by the end of next week.

It is not the good GFS run data that is plotted on this Wetterzentrale graph (it was probably the 00Z run). Note that the location taken for London is "Lat : 51 Long : 0" which is 50km south of London. They use the nearest point of GEFS 1.0deg data. The Isle of Wight thing was probably when GEFS data had a 2.5deg resolution. Same thing for the GFS op resolution. It had a 2.5deg resolution in the > 192hours part of the run until the last GFS upgrade. (On Meteociel we now use GEFS 0.5deg / GFS 0.5deg data for the graphs and interpolate between grid points, so the values are supposedly more conform for London)

Those who have been following the strat discussion for years might remember what was happening in January 2012 .... This was forecast for the middle of January ... ...not a million miles from positioning of current expected warming. It verified and the weather on the ground a few days later .... Current GFS 06Z not implausible on recent past history. Edit to add the caveat that the GFSp is more bullish with this pattern of strat warming and is possibly the reason it is persisting with the output seen on recent runs - most recent run 00Z So similar to the one above from four years ago!

Yet further reasons for perspective: 1) Regarding the next 10 to 15 days, let alone the rest of the winter, knee-jerk reactions to unpalatable model output has not come without any previous cautionary note against them I know my previous post at the weekend attempted to pre-empt this by saying that NWP would produce some underwhelming roll-outs this week. Exactly what is occuring.... These simply reflect the expected changes with regard to the renewed strengthening of the polar stratospheric vortex prior to the ongoing observation over a displacement of some unknown order (at least at this stage unknown) . The changes also reflect, as discussed previously, the tropospheric fall-out effects from a recent drop in relative angular momentum, which, combined with the position of the vortex back towards Greenland during this transition intensificstion period is inevitably adding to the polar jet and keeping the pattern flat in the 10 day period. Notwithstanding trying to state in advance that these hurdles need to be jumped, I am not sure what more can be said while a wait is in progress for further changes 2) The key to the question of further amplification lies, obviously, in when further upturn in AAM occurs (to re-amplify the Atlantic sector) and also tied in with the question of timing and strength of the much discussed vortex displacement. At present the 10 day NWP is occupied with the higher energy flatter state, and, being the evening of the 19th January, as cited above, we should not be surprised to see uninspiring output for this time-period at the very least! 3) Monitoring progress of the tropical signal in the Indian Ocean is only one part of the story (related to ebb in AAM) but watching the progress of the Global Wind Oscillation will tell the whole story regarding the total momentum budget and ultimately put the current lull into true perspective. The tropical cycle is on course to transfer eastward toward the Maritimes, but with continued low frequency Nino signal underpinning angular momentum. With this in mind, at present the GWO is according with expectations and treading some water in a slowly lowering amplitude Phase 7/6/7 pattern - with the westerly inertia across the Pacific counteracting AAM tendency fall ahead of expected further rise as we get into February. A cue for this rise to be further augmented when the MJO arrives at Phase 5 and then more especially beyond through Phases 6 and 7 during February, as it heads through the Pacific again (as it did during this month) by which time the effects of the suggested weakening and displacement of the upper stratospheric vortex should be already verifiable. 4) This is all still at least a couple of weeks ahead and more, so we must be aware in the meantime that any amplification potential in the Atlantic will be offset by the current placement of the vortex, and consequently whilst the upper zonal winds are still prohibitive, of allowing poleward ridging to take high pressure northwards and take the AO back to negative. 5) In the meantime however, the continual wave 1 activity from the Kara Sea height anomaly persists - the same activity that helped elongate the lower stratospheric vortex in the last couple of weeks and facilitate the amplification potential and provide the well signposted and anticipated -AO signature of much of the first half of January. 6) Its sometimes advisable not to get too hung about a definitive SSW - although obviously against the background of the strengthening and return to +AO of anticipated upper vortex disruption, it would certainly help on this occasion if we got one! However, an adequate displacement allied to persistent wave 1 trop/strat activity plus the MJO arriving in the Pacific should still be the cue for the best opportunity for a return to cold - and this maybe why the METO have cited the period from mid month as most likely for any colder weather. However, as deemed possible in recent posts, this is not at all to say that a colder pattern won't return before then - just that the chances increase through the month. Speaking personally, I am not sure that anything otherwise has been stated in terms of future possible prospects - albeit it has to be accepted the most optimistic prospects of the 83 Jan/Feb analogue suggestion being ahead of time no longer look so feasible 7) It would be very very easy to spend time discussing the worst scenarios that can happen - I think this post viewed as a whole, recognises and answers that anyway if one reads between the lines sufficiently. Time instead for looking at the best case scenario, which still remains - but with further evidence to hand, as just stated above, its one that demands caution and probably has to be adjusted back further into the new month: Taking a working assumption that the sum total of factors progress favourably, then the matured Nino forcing continues to evolve helpfully towards a pattern that favours greater cold than this initial spell. The tendency being for the GOA low to retrograde westwards, and downstream longwave responses being to remove any sibling lobes of vorticity over Greenland and NE Canada left over from displacement. This, allowing a more functional stronger height rise towards Greenland and Iceland than an ordinary amplified Atlantic ridge - and in tandem with upstream tropical forcing arriving back in the Pacific as Feb progresses, a greater and greater chance of securing a more east based NAO than attempted in January. However, the degree of success and extent to which this best scenario occurs, and of course any colder scenarios as a whole as well, will of course be brought about by significant enough damage to the upper vortex being secured in addition to the persistent troposphere>stratosphere interactions we have seen so far. Eight) Retrospective analysis has already been thoroughly covered and answered in respect of the changes from the New Year period and what has verified to date. However, beyond any persisting objective that might remain to find descrepancies with other members suggestions/predictions, if the main 'beef' is simply that not enough snow has fallen 'IMBY' from the recent Atlantic ridge and Scandinavian trough pattern, after the anomalous warmth of December, then there is a simple answer to that: Whilst one can certainly suggest a likely large scale pattern based on study of the longer range tools available to assist in doing so, it remains the case that for a country as small as the UK is in relative terms to the Northern Hemisphere, it is completely impossible to superimpose a larger macro scale pattern onto a micro street level atlas for each county (country-wide) and make surface condition predictions for each of them! This seems to get said every winter, if/when we get into the second half of the season and some people are feeling 'short changed' by the weather vs what some 'forecasts' appear to promise. 9) So, all in all, best relegate 'winter is over and the clock is ticking' doomwatch prophecies as an entirely uneccesary and excessively self- purgative exercise . Also not holding other members (whoever they may be) accountable for how much/or otherwise it snows, or doesn't snow - as the case may be. Keeping personal frustrations in some sensible, proportionate and mature perspective is far more helpful. Its the weather after all and not something we can intervene with and change

Oh dear more winters over posts, and no chance of snow, that's it... exactly where we were at the end of the year, and look how things changed 2 weeks on.. I rarely look in this thread.. and I will continue to do so.. its the same in the summer, washout etc etc no sun no warmth... this is a depressing thread to read at anytime of the year.

Thanks to @lorenzo, he just reminded me of the NASA GEOS5 model. Looks cool, with the nice seen region where the warming is charging from (the positive vertical velocity). We can also see some of the gravity waves. and regarding the u-wind, its is close to ECM. And also by the wave 1 strength. height wise, its going for a strong wave 1.

We certainly aren't seeing much encouragement in the operational output but I feel confident we will see positive changes soon. I did say this was a slow burner and I still feel that way but I expect see positive changes in the day 9/10 region over the next day or two. Remember this chart from this mornings GFS for Feb 2, it doesn't get much worse than this. But I think the reality will be very different. A good while back I said that we would likely see an effort to build a Scandi high in the output but this would likely fail and attention would switch back to Atlantic sector. While I was happy to cheer an Easterly on I think this is going to prove correct except we are not really seeing the Atlantic ridge and height rises toward Greenland being modeled which I hoped would appear late Jan and now there are only 11 days left to end of month. If it is going to happen anything like I thought then it needs to start showing in the next 2 days and I'm fairly confident the models will at least move away from the very dismal Southerly blocking from the Atlantic, through Europe and into Russia, yuk! Crystal ball time; I hope to see a deep trough modeled dropping into Europe and a strong Atlantic ridge behind around end of Jan. Seems to me models are over estimating the strength of high pressure to our South and how the PV in this region may split into two lobes and move SE and SW out of their Greenland home. Well it works in my head anyway, the models just need to catch on. ECM out to 168 as I post and looking a little better for lowering heights to the South perhaps though they the Euro slug is in full force here.

Not quite fishing , but a decent heads up, it thought about it on the zonal wind plot last night, this moves things into 'ramp' stages. 30mb on tonight's GFS sees a split over this period also with the vortex pegged to Siberia. Bit of a change in the last 48 hrs... Looking at the extent of that and the question of instant and lagged responses -very difficult to second guess things, looks to me though that this impacts right across the column and we are in for a quick hit.

Nothing to excite the Winter fans in the models for the next week or so with the south westerlies setting in. The earlier 06z GFS run was clearly a cold one against the majority of the suite.The next week looks rather mild/mild but looking at the ens graph on the 12z run a case could be made for more average conditions after that. the Op run trends milder after the 27th against the set. At this stage i wouldn't say more than that but we are still seeing the warming of the Strat.and forecasts of mean zonal winds decreasing over the next 10 days.This should translate into raising Polar HT anomalies in time and we can see a trend for this developing in the CPC graph as the AO index starts to slide into -ve territory. At this stage no strong signal for cold but maybe enough signs in the ens. that we are not entering a protracted mild setup ala December and with a chance of another pattern change early February as the vortex continues to warm.

Absolutely stunningly very cold frosty/icy Morning, Most of the island ranged between 0'c to around -3'c but there were some parts of the island got down to -6 - -7'c, so we decided to head out to see what photo oppurtunities we could find, it was extremely cold and was not easy to hole the camera for too long, but I manage to come across this beautiful little seen Newtown Creek, towards the North West Part of the Island, the water was also partly frozen

Lets hope the 6z suite is the fork in the road ......completely cracking...the beast in all her glory on this run!!!!!!!!!

It was a bit of leading/misleading post to be honest. There was a poster on the threads a while ago who was very good at posting historical charts and analysing them to show us how the cold made it to our shores and what the relevant set-ups were at the time. One of his famous threads was "where did that easterly come from" and it talked about historic synoptic set ups that initially look mild but then very quickly turn into a cold easterly for the UK. The above ECM chart does look mild and wet for the UK (as a whole) but with the vertical warm air advection northwards on the meridian line (which would help to inflate high pressure to the east) and the general blocked pattern to the east with a big cold pool in situ, it looks like the kind of chart that could very quickly turn into an easterly for the UK. I know the ECM 12z simply pushes the Atlantic in past the UK as the run progresses but if you look at what unfolds to the east you can see how a very cold easterly for the UK would not be out of the question.

Much better run but cold pool going to far South need further North, this Island is bigger then just the South East of England but this can improve over time i want a countrywide event please..

Woohoo Just woken up to a lovely covering of snow, currently -1.9c looking at the radar it doesn't look as though I'll get any more but temps could struggle to get over 0c today so at least this covering should stick around for a wee while.

Nice days snowsports up at glenshee today, snow a tad hard in places but overall conditions excellent! -1 deg c, slightly overcast, not a breath of wind

One has to keep in mind that 'chasing the easterly' is an annual event in the MOD thread. It's a sado/masochistic ritual that is part of the initiation tests that newbies have to pass before acceptance as bone fide members of the 'coldie club'. Hence when thrown the odd bone by the GFS it's manna from heaven and the hare is running ............

Next week looks like the mild will win for the time being alas! After that lets be honest they haven't a clue. I Will take the forecasts week by week. Off to Glenshee tomorrow decided to take the day off wok before the biblical floods come on Friday. Need my ski fix!

OP vs Control 6z

The 06z gfs puts us into the freezer next week......

The ECM De Bilt ensembles are in a word blah! http://www.weerplaza.nl/15daagseverwachting/?r=midden&type=eps_pluim Nothing exceptionally mild there but also very little cold apart from the cold outlier! I don't see a return to the December horror show but apart from that it just looks uninspiring. Towards day ten theres a couple more colder solutions that break away from the blah cluster! Wind direction wise theres a few that go more nw and also some more in the east/ne. I'm doing my best here to spin some interest!

Hi Folks! As one cold spell ends perhaps another one begins.... So whats been on the table today if you want cold? A good 00z gfs, followed by a stonking 06z and a terrible 12z. The Ecm produced a terrible 00z run ,but a very interesting run from the 12z. We are now entering deep mid winter, and entering the coldest part of the year for the Northern Hemisphere. So enjoy the rollercoaster....Lots to play for...

Some encouraging posts and signs we may be about to see the polar vortex hit considerably over the latter part of this month, setting up a different northern hemispheric background as we enter February, one far more conducive to producing a colder outlook and more importantly also perhaps a drier more blocked set up. So whilst the immediate outlook looks less than inspiring for anyone who likes cold settled weather, in the background significant building blocks could be emerging towards a very different set up come next month.

Latest from the woodshed for the beginning of Feb

Somebody been adding charts from February 1991 into current output? 1991 looks better though with the high further west & better Atlantic undercut.. Hope this becomes the new trend! Won't hold my breath though... GFS GEM Feb 1991

I reckon Netweather doctor the charts occasionally to ensure the traffic through the site stays high. Lol!

I was just about to post in the model thread but a cold spell now looks 100% nailed on for Scotland for around the 15th - 27th February! No point checking the models though - work have told me I have to be in the US for 2 weeks so that pretty much guarantees it. Enjoy it folks

A min of -5.0C on the nose at 6.20am this morning. Stunning out there and the ground has firmed up nicely. Here's my BFG impression.

Not particularly for last year - but we were recently discussing on twitter the importance of the Kara high for AO and NAO blocking events especially when combined with SSW's. Low heights in this region combined with no SSW gave the worst AO/NAO outlook and a strong Kara high combined with an SSW gave a great -ve NAO. The hard work was yet again supplied by the brilliant Ant Masiello. If you go to the tweet chains then you can see a comparison of the years

resurrection of colder continental flow in further reaches of run.... this always remains a latent prospect whilst the very cold pool remains out east

Karyo Do you only make posts in this thread with a negative tone?

I beg to differ. The models have been consistent with a positive NAO i.e low heights to our NW with high pressure to our S for many days now. The models have also been consistent with high pressure to our NE. The problem is even if we do see low pressure going underneath the high to our NE, the low heights towards Greenland are likely to prevent the block to our NE to extend W. I seem to recall some forecasts based on teleconnections saying the end of Jan/early Feb is when winter will bite. Well at the moment I see no evidence of this in the output. Infact the current output is like something from a horror film. Maybe the forecasted cold spell will be put back to mid Feb.

I must admit I've enjoyed the past couple of days , a good sharp frost,and bright sunny days, makes you feel better in yourself. How anyone can say that they prefer Atlantic driven mild crap is totally beyond me. It's about as much use to anyone as a marzipan crowbar

Well it is a start That high needs to back a long way west but at least we have a block reaching the eastern side of Scandinavia instead of the high being back over Siberia like previous output.

Well after that GFS run I'll post GEFS 14s FI chart just for fun, as it's not too bad... The METOs outlook is actually ok so let's just get the next week out the way with then things will get much more interesting!!! I'd put Atleast a £1 on that.

Maybe not but at +300 hours, the greatest uncertainty is to our north east.

if the 12z show what the 06z GFS produced, or something close I will be a happy Karlos http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=192&mode=0&carte=1 After securing my tickets for Barca V Arsenal at the Camp Nou today, that would top my day off!! Overall just seeing if the trend exists or not

Yes, Tomas forecast looks a bit more relevant now. I actually thought it was a very good presentation and he explained his logic perfectly. Shame it wasn't more appreciated on these forums as the message was badly misrepresented.

Been looking through the GEFS 6z ensembles and the majority show high pressure near us after the 180 hour mark. Just over half show a movement of that block of cold to the east, westwards. Around 4-5 show some form of easterly between 200-300 hours and around 2 of these show a beasterly. For example, run number 17 shows this at day 11- which equates to this in terms of upper air temps- No gurantee of an easterly, but no gurantee of a south westerly. It's all up in the air, and I for one, am looking forward to the next 5 days of model watching. There could be something brewing

Probably dreaming here.. as this doesn't even happen on this unlikely run.. but if only we could get an intense cold pool go into France like this, but then get dragged NW across us by an undercut.. the Channel could become a 'lake affect' snow machine!

GEM gets very close to an easterly at day 9. It has the low over the med - Hope is not lost but remains the outsider

America is a huge continent so there is always going to a massive snowstorm somewhere on most days during winter.

One positive this morning is that there are more colder ensemble members on the gfs in the medium to long term. Lets see what the ecm ens look like.

Hopefully today was just a day of 'bad luck' with model synoptics and despite being in the minority its good to see that as per Fergie saying, synoptics favouring cold do have some support at the moment. Also charts from today showing heavy rain and storms returning and still staying there with the Euroslug in place a week to 10 days out from now are not in the close enough timeframe to verify, what good is taking these horrible model runs today as 'gospel' when they easily flipped from the stellar runs from yesterday and will probably flip again. If some of the bad charts from last week actually verified upon which people also cried 'winter is over' we would have be seeing heavy rain and milder temperatures already since the weekend, when some saw snow. Also these wild swings in runs day by day, as outlined by Tamara, could be a response by the models of the impact of strat warming, once again, that cannot be ruled out when there is good support building for such an event to happen. What has perhaps been a bit overlooked is the possibility the models today overdid the signals arising as a result of the possible precursor to the displacement of the vortex (temporary strengthening = milder conditions returning) We may see in the coming days and weeks, this is all the result of the atmostphere battering the vortex into submission which should a SSW occur afterwards or even sufficient vortex displacemet, kill any re emerging Euroslugs and get us the cold we all crave. Uncertainty is the key word here and what we can continue to hope for is a switch to a better outlook again and that these runs are still too far out to be taken as a serious reflection of future weather conditions and that strat warming gains considerable ground as we move into February which looks more and more likely. All hope is not lost

A cold one -2*C at the moment not a drop of wind, cold for an inner London borough. In the suburbs it must be -4*C or lower, Benson is nippy sitting at -6*C I think we could go lower than -8.4*C? If there was some snow-cover without question I'd say double digits for that part of Oxfordshire, I'm sad to see this weather disperse after Wednesday back to mild SW'lies.

Had a few snow showers today with snow cover still in place. The snow showers were not seen on the radar and not forecast either! I keep looking at the forecasts but they seem to have no relation to what is actually happening. I'm thinking I may as well get into delivering forecasts myself based on nothing more than my lifetime experience as a time-served Scottish person and general knowledge accumulated whilst living as a human on planet Erf...tomorrow will mostly be full of weather, cauld for some with a top temp. of brass and a low temp. hanging around baltic. Precipitation could happen anywhere ranging from smaw rain tae snaw or no at awe. That should cover it then, enjoy your weather folks.

Do bear in mind the very different evolution into medium range touted by 12z GFS-P. It's not wholly without support elsewhere, albeit a minority probability presently.