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Meteociel - Cartes du modèle numérique GFS pour l'Europe GFS still showing extreme cold to our NW over next few days. Apologies if chart doesn't appear..not yet fathomed how to upload charts from my tablet!

Meteociel - Cartes du modèle numérique GFS pour l'Hémisphère Nord GFS continues to model very low 1000-500 thickness values over Central and southern Greenland (below 474) where the surface temperature was -54 C on Saturday. The extremely low thickness values are set to position themselves over southern Greenland over the next few days and closer to the UK than I have seen for many years. Of course it will not have much effect in the UK but demonstrates geographically just how close the UK is to the Greenland Icecap and how desperately cold it is not that far away.

GFS is modeling extreme cold to out NW over next few days The temperature over Central Greenland recording -51 C at midnight and -39 C on the Greenland east coast. The cold modelled to be locked into the Arctic and intensifying during our current highly mobile spell. It is somewhat unusual to see such perilous cold so close to the UK although a couple of thousand miles away I suppose is not that close. Svalbald too has been between -15 C and - 20 C over the last couple of weeks which must be increasing the ice build up around its shores.

The high to our east is modelled to remain over Europe for the next few days with attendant warm days and some foggy nights. Dewpoints further to our east and southeast are impressively low and some of this very dry cold air must inevitably filter into the southeast of the UK. Fog may become less extensive but nights could turn very cold with some hard frosts where skies remain clear.

Whilst hunting for cold just now I notice Svalbald -21C, East Greenland -36 C and a 1000-500 mb thickness cold pool of 474 DM just north of Lapland. The intense high forecast to be to our east in a few days time is expected to suck up unusual warmth. If skies remain clear under the high an inversion is likely to develop with cold possibly foggy nights and potentially warm days. Where any fog forms it could be slow to clear with temperatures close to freezing in these parts. Along the south and east coasts where more of a breeze is likely temperatures are likely to be suppressed by the cool sea but mixing with the warm air aloft due to the breeze may alleviate the effect of the cold sea. It will be very interesting to see how the high behaves with such cold air surrounding it and a island of unusual warmth covering the UK.

A good 2.5 cm of snow in the west of the Isle of Wight at the moment with continuous moderate snow.

Satellite imagery shows an extensive snow cover over northeast France and the Low countries from the heavy snow there over the last couple of days. This acts as an ice sheet suppressing surface temperatures and with the wind direction modelled to flow from the SE it must increase the chances of wintry precipitation to southern coastal counties. Also 06Z GFS precipitation chart has the snow area slightly further south than the previous run now very close to the south coast. It is fairly rare to get snow actually laying on the south coast however parts of the south rise up to around 800 feet so from an imby prospective all to play for.

Sounds good to me !

The record for a Siberian high is 1083.8 MB which occurred at the end of December 1968. I remember trying to convince a colleague it was a high we were plotting on the circumpolar chart and not a low as only the last three digits of the value were coded and plotted.

Low resolution 12Z GFS shows a powerful Russian high 1060 mb moving westwards to our north and ridging towards Greenland.

Was is Kusamo in N Finland a few years ago and it was -36 C. Looking out it could have been -1 C as there was little hoar frost as the air was so dry. A local lady was out walking her dog !

Low Res GFS 06Z NH profile is about the best that we ever see.

Many thanks Mike.

Does Net Weather have a list of acronyms ? I am struggling with NAM, PNA, STJ, COD for example.

Yes it is 384 but unusually deep cold air is poised in just the right place to the north of Iceland and looks ready to sweep down across the UK. All change next run.

This is certainly what GFS is suggesting. The high to the east builds as very cold air is brought ever further west into Europe while at the same time the low struggles to make progress against the developing block.

Some improvement on 06 Z GFS mid range with Russian high positioned much further northwest than 00z with trough disruption beneath the ridge forcing very cold air back as far west as Denmark.

Although I am unable to reproduce the fax charts here I have just toggled between the latest T+96 and the T+120 and was surprised to see such a dramatic westward extension of the cold air towards the UK by Saturday.

Changes are occurring as early as T +72 with repeated westward corrections near the UK with fronts held to our west as warm air surges north aiding the building of a significant ridge to our east. Watch near time to see if the trend continues tomorrow.

Latest UKMO T+84 fax resembles a chart from an earlier decade with a big high to the NE, trough disruption over the UK and with an occlusion trying to move westwards across the southern half of the UK. A bit of a westward correction when compared to the previous run e.g yesterday evenings T+96. http://www.wetterzentrale.de/pics/brack2a.gif http://www.wetterzentrale.de/pics/brack3.gif

Agreed. UKMO, ECM and GFS have all been entertaining the idea of some sort trough disruption close to the UK over the last few runs with a tendency to build high pressure somewhere to the NE. We could be witnessing an evolving easterly in the medium term.

http://www.meteociel.fr/modeles/archives/archives.php?day=25&month=1&hour=0&year=2012&map=0&mode=2 Not so very different to what GFS is modelling this week and this spell was only 3 years ago. It ended up in early February with the SE of the UK coming under the influence of proper Siberian air one of the few occasions in the last hundred years or so.

http://www.meteociel.com/modeles/gfse_cartes.php Big changes from around T+120 on 12Z GFS backed up by latest UKMO as trough approaching UK slips south giving lower heights to S of the UK as weak ridge tries to build to the N/NE. Seem to remember that the recent cold spell appeared out of the blue at around T+96.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html Latest 8-10 day 500mb charts continue to show low heights in the eastern Med and Azores preventing the Azores high from assuming its normal position. ECM has the axis of the ridge extending from mid Atlantic to Russia slightly further north with respect to the UK compared to yesterday. GFS has the upper high cell over Scandinavia further to the NE than yesterday. The upper ridge and associated surface high will have difficulty sinking too far south while low heights continue to be modelled from the Med to the Azores.

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=186&code=code&mode=0&mode3h=0&runpara=0&carte=1 An omega block in the vicinity of the UK by around T+174. It could do with being a bit further north but nevertheless a rare sight.