Never believe the models when they are forecasting cold at t120 and beyond - they invariably back-track when we get closer to the time.

Here in Copenhagen, it is sub-zero and snowing this morning, but it is predicted to turn mild and wet by Sunday, so not much sign of a protacted cold spell in this neck of the woods.

What gives you the impression that yesterday's runs were any more likely than this mornings? 😉

As you surely know by now, medium range forecasting is about slow collation and confidence in trends over successive model runs. Taking all available data and cross-analysing. There is also a fair degree of information that is not freely available. If you'd said 'based on X op run of Y model, it's looking cold and wet' then fair enough, but based on probability as indicated by trends, clusters, means and anomaly spreads across the suite of available resources, it's looking cold and wet', then I'd also have to agree with you with the caveat that snow is more likely than not for many areas.

GEM FI going down the cold route this morning with a very negative NAO.

http://www.wetterzentrale.de/pics/Rgem2281.gif

Morning, well we'd only have to wait until late March then this year LOL.

Ecm Mean looks similar to the Op this morning. It's going to get cold how cold for how long and if we get any snow still all up for grabs.

http://www.wetterzentrale.de/pics/Reem2401.html

The verification stats indicate ECM is more accurate at five days by a few percent with GFS and UKMO more or less joint second - this is for N Hemisphere 500mb anomalies so a very broad brush.

Subjectively we will all have different opinions with regard the accuracy for W Europe as the general concensus is GFS models the Atlantic fairly well but tends to be more progressive with track and intensity of lows, but ECM is better at mainland Europe with a better handle on blocking highs. Very general I know but for the +120hr mark I'd take ECM over GFS.

You know what, I'd bank ECM's take on this. Yes, it is 240 hrs away and this won't exactly bring the much fabled snowmaggedon we all so crave, but anything to stop the Atlantic train in it's track will be most welcome by me . . .

Morning all.

Very mixed messages for next week looking at the latest data. Some snow for sure I would think, probably best for those with elevation up North. Not too sure about the prospects for the rest of the country, a bit of a toppler situation is favoured by ECM which you would have to say could be a very reasonable call. At least if that was the case then we would get a somewhat less wet scenario and some frost too.

Pretty good agreement on a cool down on the dutch ensembles.

Thats an interesting interpretation of the ECM output 

http://meteociel.fr/modeles/ecmwf/runs/2016010500/EDH101-240.GIF 

UKMO is probably my favourite this morning. Not keen on how ECM ends. Just a toppler as the PV reestablishes over Greenland and we go back to pressure to the south with sw'lry's on subsequent runs. Long way off and won't happen like that but most of us want to see the pressure build and maintain where the PV usually is.

You mean like in the link above? 

Should mean it becoming less wet though Doc, what ever happens that's got to be the most important outcome?

There will be some flip-flopping to come for sure.

Could be some stellar runs for cold to come in the next few days before the obvious downgrades to reality.

If that's representative of the mean for all the ECM runs then we can have a Delboy moment and say "Lovely Jubbly" but it's not what's displayed on the op albeit as an isolated run.

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 TUESDAY JAN 5TH 2016

THE CURRENT GENERAL SITUATION A filling depression lies across Southern parts of England and Wales, becoming slow moving with a chilly SE flow over the NE with an occluded front lying slow moving in situ. Further frontal system will approach the SW later tomorrow.

http://www.wetterzentrale.de/pics/Rtavn001.gif

CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the British Isles ranges from between 1500ft just to the NE of Scotland to nearer 5000ft over Southern England. Snowfall can be expected across the hills of Scotland today and tomorrow especially the mountains of NE Scotland.

http://www.snow-forecast.com/maps/dynamic/uk

http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow.gif

MODELS-2 WEEK HEADLINE Continuing unsettled and very windy at times with further heavy rain or showers at times. Perhaps drier and colder for many later next week

THE GFS JET STREAM FORECAST The main theme of the Jet Stream today shows the Jet Stream incessantly crossing quickly East across the Atlantic and generally to the South of the UK for the next week to 10 days. Towards the end of the run there is some indication of the flow returning to lie North of Scotland still travelling in an Eastwards direction.

http://www.netweather.tv/index.cgi?action=jetstream

GFS OPERATIONAL The theme of the GFS operational run today shows deep Low pressure areas affecting the UK over the next 10 days or so. The centre of the depressions will often lie across the UK for the next 10 days or so bringing rain and showers to all areas and as the air turns somewhat colder for a time next week some of the rain could turn to snow over all hills and winds turn more towards the North. Then High pressure slips down to the South and SE of the UK and builds at the end of the run with winds turning to a milder Southerly direction again with dry, benign weather conditions likely for most and any rain restricted to the far NW but with some frost and fog patches by night in the South.

GFS CONTROL RUN The theme of the Control Run is very similar to the Operational run this morning up until Day 10 with rain and strong winds in largely cyclonic conditions with temperatures falling somewhat next week with more snow on the hills at times and some frosts at night. The departure from the Operational Run leads us into another wet and windy period to close out the run as Low pressure from the Atlantic streams back across the UK with rain and strong winds for many in average temperatures.

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

UKMO The UKMO today shows Low pressure in total control of the UK weather over the next 6 days with rain and strong winds at times as renewed Low pressure replaces the existing centre over Southern Britain later this week. Temperatures will largely remain close to average through this period with some snowfall on northern high ground at times.

http://www.wetterzentrale.de/pics/Rukm1441.gif

THE FAX CHARTS The Fax Charts show a continuation of the unsettled spell with strong winds and rain at times on troughs repeatedly driven across the UK in a SW flow decelerating and becoming slow moving across the NE of the UK with broadly windy and showery SW winds elsewhere in average temperatures overall.

http://www.weathercharts.org/ukmomslp.htm#t120

GEM GEM this morning also shows Low pressure close to or over the UK over the next week with strong winds, rain and showers circling the UK throughout. Temperatures close to average then fall back to rather cold levels next week with winds more Northerly allowing cold air to sink South to all next week with showers turning to snow and frost at night becoming more widespread.

http://www.wetterzentrale.de/pics/Rgem2401.gif

NAVGEM NAVGEM maintains a very volatile situation over the enxt week with strong winds and heavy rain at times for all. A notable storm system is shown to cross the South early next week introducing severe gales and heavy rain followed by colder conditions in it's wake as winds swing to the NW with showers turning more readily to snow over the hills over many parts of the UK by day 7.

http://www.wetterzentrale.de/pics/Rnvg1681.gif

ECM ECM today shows another week of strong winds and heavy rain at times as Low pressure remains anchored over the UK over the next week before shifting slowly off to the East. After the heavy rain and showers of the days to come winds swinging North or NW next week bring colder air to all with some wintry showers likely even in the South for a time next week before High pressure to the west ridges in later drying things up but giving a more seasonal flavour of rather cold conditions with frost and fog patches night and morning and a few wintry showers still in the East and SE.

http://www.wetterzentrale.de/pics/Recm2401.gif

ECM 10 DAY MEAN The 10 day mean chart shows Low pressure likely to the NE in 10 days with a strong ridge of High pressure just to the West of the UK. With the Jet stream still showing averaging South and West of the UK lying on the cold side of it would mean cold weather with wintry showers in places especially the North and East.

http://www.wetterzentrale.de/pics/Reem2401.gif

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The theme of the output has strengthened towards drier and colder conditions developing across the UK next week. 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 UKMO and GFS at 96.5 pts respectively. At 3 days ECM is leading with 97.6 pts to UKMO's 96.9 pts while GFS lags behind at 96.4 pts. At 5 days ECM leads with 89.6 pts to UKMO at 87.8 pts then GFS at 87.4 pts. Then at 8 Days ECM still leads at 64.9 pts over GFS's 61.5 pts. Finally at Day 10 ECM ties with GFS at 46.2 pts each.

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 There are increasing signs of change at last within the output this morning towards drier and somewhat colder conditions across the UK from next week. As is usual when model outputs show these type of changes in Winter there are a lot of rollercoaster moments along the way with output showing all sorts of options between wintry armageddon and just a two day cold snap and all things in between and while I personally don't think that anything remarkably cold or snowy is likely a marked change in temperatures to what we have become accustomed to this season so far is likely for all areas. Before we get to that we have another week of deeply unsettled weather as the UK lies under Low pressure giving spells of wind and rain affecting all parts with snow on the hills of the North but temperatures near average for many. It's not until the eary days of next week when the deep low complex across the UK drifts slowly east opening the door to the North and NW for cold winds to accelerate South across the UK. With pressure only recovering slowly wintry showers will probably affect all areas for several days with some wintriness possible even in the South. Frosts at night then look like becoming widespread continuing on into the latter part of next week as it looks like High pressure to the West ridges across the UK for a time with frost and fog night and morning becoming a welcome shift from wind and rain. The jury is then open on how long this lasts and there remains some output which shifts things back towards a westerly milder pattern quite soon but with the Jet flow predicted to be much weaker by then the chances of High pressure hanging around and becoming a much more dominant force in our weather is greater than at anytine recently. So it's a case of watch the models over the coming days and continue to ride the rollercoaster of the ups and downs of an upcoming cold spell always fraught with danger across the UK. Things I think will not become clearer until the coming weekend when some greater cross model agreement on how things pan out next week will arise.

Next Update on Wednesday January 6th 2016 at 09:00 approx

Obviously hypothetical at T240 but I don't think we would be back in mild southwesterlies if you took that chart forward as heights remain low over mainland Europe, I think the High would end up over us and then what happened after would depend on subsequent drivers.

Agree 100%. After two months of there being hardly a fully dry day here, a change to a more HP dominated set-up would be very much welcomed by me.

I have been saying since before Christmas that a dry or drier spell is more of a necessity now than a wintry spell; maybe at long last the weather is starting to wake up to that if the models have it right.

I'm pretty sure that everyone in the areas recently hit by flooding will be hoping that we do get an area of HP right over us sometime in the near future, Ian. That at least would guarantee a mostly dry spell of weather and would allow these areas to recover to some degree from recent flooding events.

Changes are on the horizon, changes to colder wx but more importantly changes to generally drier conditions too overall as Jan progresses

https://twitter.com/MattHugo81

A change is on the way by the looks of it.

[quote=nsrobins;750461]

The verification stats indicate ECM is more accurate at five days by a few percent with GFS and UKMO more or less joint second - this is for N Hemisphere 500mb anomalies so a very broad brush.

Subjectively we will all have different opinions with regard the accuracy for W Europe as the general concensus is GFS models the Atlantic fairly well but tends to be more progressive with track and intensity of lows, but ECM is better at mainland Europe with a better handle on blocking highs. Very general I know but for the +120hr mark I'd take ECM over GFS.

[/Thanks for the reply, i only made this post as a lot of people seem to look at the GFS system as it updates every 6 hours and sometimes with  massive differences, it really is quite unreliable. /quote]