Model Output Discussion 29th December - Into mid-Winter.

[nick sussex]

The GFS makes a slight backtrack but we need a lot more than this. Its view is still different to the ne from very early on within T96hrs. Having said earlier we're not dealing with a shortwave drama I forgot the blasted one in Russia which the GFS makes a meal of, this stops better ridging from the Russian high. You have to get the ridging west otherwise too much energy spills east and not se. You can see here how much further east the GFS is.

[tight isobar]

Agreed the spread. ..sporadic at that...with shortwaving interrupted' is an eyesore to say the least. .

However disruption of warm-air-advection' cross polar can and/will have disruption for devolving (minor lp's)..as momentum gains via cross polar engagement! ..

Its a developing scenario. ..and quite simply one that makes the kid in me rise to the surface. ..

Output is now beginning to enlighten myself. ..

Edited January 3, 2017 by tight isobar

[booferking]

Big differnce 216 vortex spilit compare to earlier run

Edited January 3, 2017 by booferking

[johnholmes]

1 minute ago, tight isobar said:

However disruption of warm-air-advection' cross polar canand/will have disruption for devolving (minor lp's)..as momentum gains via cross polar engagement! ..

Please may we have sentences like this in English, I honestly have great difficulty in trying to understand some of your posts. I do not mean to offend simply ask you to explain what the above means please?

[bluearmy]

The split vortex provides the background for the amplification out west on this run. Prior to that the troughing N of the Azores (remember that ) was nterefring with the retrogression. How far south the low heights mange to get will be interesting 

[tight isobar]

@john Holmes

Apologies john..I've edited my former..

If there's anything else you would like me to elaborate' id be good to go..Regards

 

T-I...

[bluearmy]

2 minutes ago, nick sussex said:

Any chance that Euro slug high might get lost before I'm pushing a zimmer frame around! Jeez just go!

It's going this time nick - all the ens runs can't be wrong day after day ....... can they? 

[feb1991blizzard]

3 minutes ago, johnholmes said:

Please may we have sentences like this in English, I honestly have great difficulty in trying to understand some of your posts. I do not mean to offend simply ask you to explain what the above means please?

Actually John - his CPF is not out the equation by the end of this run, this run is a stonker.

[radiohead]

Interesting FI incoming on the 18Z...

[Allseasons-Si]

An FL bank

mid Jan on wards cold spell,stick it in your head

 

[TEITS]

Always encouraging when despite the differences between the GFS & UKMO/ECM at +96 the GFS still continues to suggest a cold outlook.

What the 18Z does to the PV has been shown a few times in recent days. Note how the PV is backing W towards Alaska which I think BA mentioned earlier.

However im still in the camp of Steve M & Nick S. Strongly believe the GFS will backtrack towards the Euros. Now whilst im not expecting any significant cold at +144 there is scope for a westward shift in the overall pattern..

[Guest]

WINTER 2016/17 FULL REPORT No. 6 WITH JANUARY 3RD INPUT

Please note that some of the charts that I refer to in this post are through “live” links which update periodically. So, if you are reading this a few days or even hours after publication (on Tuesday, January 3rd at 2300), some of the charts may already have updated. My comments relate to what the charts were showing at the time of this posting. I am just starting to learn how to cut and paste charts into my posts so please bear with me as I increasingly use these in future reports .I hope they copy okay.

This report will start off with a New Year message, then explore some of the reasons why the model output has been even more variable than usual. I will provide detailed coverage of Judah Cohen’s latest Arctic Oscillation report which should be hot off the press just after I’ve finished wrapping up the rest of my report by the end of this evening (and it's much better news for coldies as far as Judah is concerned). I also include all my regular features.

A New Year Message To Everyone On The Model Thread:

This part of my report is not intended to come across as an arrogant point of view but is an appeal to all those who use this thread.

First of all, a Happy New Year to everyone. For all the coldies (including myself) I hope that we shall see at least one or two decent cold spells before this Winter is over. The same goes for those seeking Summer warmth or whatever type of weather appeals to you (we can’t please everyone all of the time!). Whatever 2017 has in store for us, I hope that we can all enjoy the vagaries of the British weather throughout the year and continue to improve our understanding of this fascinating subject.

I would like to see a New Year’s resolution by everyone to do their bit to help keep this forum a happy place for presenting, discussing and responding to posts. We need to understand the huge diversity of members. This is not just a mixture of ages, the sexes and backgrounds but the sheer range of experience from newbies just starting to learn and understand the subject, keen amateurs like myself, those with greater technical knowledge (some fully qualified but many self-taught) right through to the professionals (some active and some retired). On top of this we have a lot of members who mostly only read but rarely or never post. Many come on here to see beyond the daily forecasts or what is behind them. With such a diversity of people, it is little wonder that misunderstandings can develop, disagreement and criticism can become quite personal, patience can be tried – sometimes to the limit, emotions can run to fever pitch and bad behaviour can become rife.

We need to appreciate that the moderators can have a very difficult time presiding over us. There has been a big clampdown in recent days on removing unsuitable posts altogether and moving “off-topic” posts to other threads, particularly the moan and ramp thread. There have been repeated warnings and links to some of the rules and guidelines. When we had the most recent disappointment following the “generally” (but not exclusively) optimistic model output suggesting some proper cold for several days followed by the massive downgrades and back tracking, someone actually commented that it was surprising how so few posters seemed to be “throwing their toys out of the pram” (or the equivalent). Well although a few might be learning how to manage their emotions better after a series of similar disappoints already this Winter as well as in many previous Winters, the main reason was simply due to the moderators making an enormous effort to carry out all their warnings. Just as exciting model output can lead to ramping, poor or dire output can lead to all hell breaking loose. By removing the posts with the more extreme and unpleasant reactions, this place can start to look more than half respectable! One correlation to this is the political debate in Parliament. MPs can often show a lack of respect during debates and the Speaker often needs to intervene. Then at Prime Ministers Questions we often see some very childish behaviour. While a small number of people might find this “entertaining”, the vast majority will loose the little respect that they might have had for many MPs. The message has to be before you post on this forum, think of the wider audience who will be reading and forming an impression of it.  I will not repeat what I said about bad behaviour and managing one’s expectations in my last two reports on pages 167 and 236 of the last (5th December 2016) model thread but I will expand briefly on how we can all help.

Newbies, especially those with very limited experience of the science, need to understand that some posts by necessity are of a very technical nature. If you have a genuine relevant “on-topic” query, please do not be discouraged from asking it. If you feel it’s rather “off-topic” then send a PM to the poster or raise the matter on a more relevant thread. If you are completely unsure then a short PM to the moderators might be best. Whichever of these routes you take, you will find that the vast majority on here will be pleased to help you directly or point you in the right direction.

For the more seasoned posters it’s simply a case of taking a step back before you post or reply and asking yourself just how would you react if that post was directed at you. We know that many readers and the moderators do not like one liners unless they really add something to what is being said and are “on-topic”. There are a few posters like me, who prefer to produce much more occasional but far more in-depth posts. I do keep most of each of my posts model related but I like to look at it all from a slightly different perspective and I try to find a few things to say which have not always been covered elsewhere. I am not referring to these opening paragraphs which I only feel compelled to write when the thread has exhibited far more bad behaviour than should be tolerated (in my opinion).

Now I come on to the much more experienced posters including the professionals and the moderators. Last week before the downgrades, even a “few” of you guys were guilty of ramping. You allowed yourselves to focus on a single (or just a handful) of particular models when they were showing some of the best routes to cold. As you have the greatest followings you need to be particularly wary of using throw away comments. A number (not all) of the Tweets from (usually) well respected professionals and commentators get posted directly onto this thread. The majority of these are purely that person’s reaction to just a narrow amount of model output. This sort of message is normally aimed at a particular following and is often purely publicity grabbing. I even include Judah Cohen here even though I have the greatest respect for his well-balanced reports, his one liners rarely enhance his reputation and probably damage it more often than not! A little irresponsible reporting can feed the frenzy and thoroughly mislead the majority of readers.

We have a few regular posters on here who are almost always utterly responsible and who deserve a special mention. I will name four of them but the list is a little longer. One is “Knocker” who always tells it as he sees it without any ramping. I do not feel that anything could knock him off course!  Another is John Holmes, who like Knocker has considerable experience and explains the ensemble charts so well to us. John is very careful to ensure that his views are expressed neutrally. Then we have Tamara and Nouska, who have built-up their own knowledge and experience mostly through self-learning and specialist reading. Although I have been around this subject almost all my life (as an amateur), I simply do not have sufficient skill to fully understand parts of the science associated with some of the teleconnections. When these ladies speak, most of us listen out of respect. They do their best to manage our expectations but they are sometimes quoted out of context.

That’s the end of my New Year message but I sincerely hope that most, if not all of us, will make a real effort to make this a better place for everyone.

 Why The Huge Variability in the Model Output?

Let’s look at this in a simplified way. The models are always a moving feast. At the best of times we might see some good consistency in the output up to a week or so out and then a greater divergence from D7 and particularly from D10 and beyond while the models explore some of the possible outcomes based on often quite minor changes in the short-term period. During the Northern Hemisphere Winter half of the year (October to March) the atmosphere goes up a few gears. Land cools off more quickly than the oceans creating thermal contrasts which can strengthen the Jet Stream for long periods. The polar vortex in the stratosphere and the troposphere is usually at its strongest around the turn of the year and either side of it. Cold air is locked up in the Arctic. Warmings in the stratosphere can work their way down to the surface with a widespread displacement of the Arctic cold towards the middle latitudes (most extreme during a Sudden Stratospheric Warming event which do not happen every Winter). Warm air advection at the surface such as that delivered by a powerful Jet Stream can have a similar but rather more localised effect with cold air moving down in one or more areas with the larger land masses in the continents of North America and Asia usually more favoured than other areas.

Now to the more complex bit which is beyond my ability to explain other than in the simplest terms – the teleconnections. The various oscillations in different levels of the stratosphere can have significant impacts which might vary hugely from year to year. The ENSO, currently close to neutral but very slightly trending to La Nina conditions, the west based QBO, the shorter term cycles like the MJO, the strength and position of the PV, the ridges and troughs in the stratosphere (influencing those on the surface), the extent (or lack of) Arctic Sea ice and the amount of solar activity to name just some of them. Sometimes one of these forces is more dominant but there is usually a strong link between them. At other times, some of the signals are masked by other signals. I have noted some of the comments in recent weeks such as very weak signals, often conflicting signals, stratosphere and troposphere disconnects and the reverse with strong correlations between the two!

This Winter, following on from much of the Autumn has seen persistent MLB with an anomalous area of high pressure never too far away from our shores. In my report last week, I did a brief review of 2016 which highlighted the number of extreme events. This included, a record strong El Nino last Winter, a near record strength PV for much of the 2015-6 Winter and now into this Winter, a record weak PV which has strengthened to a very strong one in recent weeks and record low Arctic sea ice build-up during the last three months. These extremes have presented new challenges to those who understand the teleconnection science and signals. Part of the models’ input is based on these signals.

The longer range forecasts generally predicted a substantially blocked December and we had exactly that. The change to zonal after mid-month (week 3) barely materialised with high pressure quickly reasserting itself after Christmas. We then see forecasts of a pretty blocked January. The trouble is that almost all the blocking has been MLB with little in the way of any cold for us so far. I do not feel that some people realise just how unusual the pattern has been. It is difficult to believe that we could go through much of the Autumn and all the Winter without this type of pattern evolving at times to produce a longer period of HLB. The trouble is that we have the strong PV. This, as well as the complex signals that I just mentioned above, seem to be at least partly at odds with each other. Following due warning from the likes of Tamara, we were told that a “prolonged” period of HLB would be highly unlikely until “at least” later in the Winter (not necessarily during mid-January as some seem to have interpreted those comments but “after” that period) and even this was not presented  as a given.

It really is not at all surprising that the model output has been so volatile even down to the more reliable periods around D5 to D7. With these conflicting and sometimes weak signals, there is a very fine margin indeed between MLB with a flatter pattern and some modest HLB with a more meridional pattern. We have also seen the occasional output showing a more mobile Atlantic and sometimes even a longer period of zonality. The Jet Stream has been split for a while and the models have struggled with the direction and strength of each arm. January often sees some of the greatest thermal contrasts and most powerful Jet Streams. Almost all the models and the large majority of their ensemble members (I have not looked at the 12z output yet and I do not believe in being swayed by just one run anyway) are still showing a high degree of blocking with a continuing mix of mostly MLB and some HLB.

Right, now that I have got the bad news out of the way, I still believe that we have a whole host of interesting possibilities to give us a chance of something better during this Winter. We may well go through almost the whole Winter without any prolonged cold but there are enough pools of cold around and some of these should get very close to us. Even with predominantly MLB it is still possible to have occasional Arctic outbreaks or (still muted as a “low” probability) a Scandinavian high pulling in some of that very cold air locked in to our east. I can recall many much more mobile Winters with significant cold snaps, albeit lasting for little more than a week. Some of our greatest snowstorms have come in predominantly mild Winters. This January looks like delivering below average temperatures overall but even that is not always enough.

I have noted a recent trend on the thread which I feel is a good one. This is to focus far less on the fine detail from run to run (especially beyond D5) and to look out more for the various routes to cold. I feel that sooner or later at least one of these “possibilities” will verify down the line. So, we should all enjoy the hunt and bear in mind that this is a very unusual pattern that could easily fall into place to deliver at least something to reward our patience. If it all goes wrong again you can shoot me down as long that is not literally!

Dr Judah Cohen’s Latest Arctic Oscillation Report:

Here is the link to Judah Cohen’s latest update published at 2310 on January 3rd.  

http://www.aer.com/science-research/climate-weather/arctic-oscillation

Now I copy his summary and impacts below.

" Summary

The Arctic Oscillation (AO) is currently neutral and is predicted to first weakly trend positive week one and then trend negative week two.

The neutral AO is reflective of mostly negative pressure/geopotential height anomalies in the eastern hemisphere of the Arctic and mostly positive pressure/geopotential height anomalies in the western hemisphere of the Arctic. With positive heights over Greenland, the North Atlantic Oscillation (NAO) is currently negative.  With heights predicted to fall near Greenland next week and then rise the following week, the NAO is also predicted to first trend positive and then negative. 

With the drop in the AO/NAO over the past week, cold temperatures have become more widespread once more across the Northern Hemisphere (NH), especially northern Eurasia.

With the AO predicted to be in an overall negative trend, widespread cold temperatures are predicted for northern Eurasia including Europe and East Asia over the next two weeks.

Cold weather is predicted to expand across North America as well but with the greatest negative geopotential height anomalies predicted to remain over western North America, the coldest temperatures will be focused in western Canada and the northwestern United States (US).

A couple of poleward heat fluxes will switch the winds from westerly to northerly in the stratospheric polar vortex (PV) first over North America and then over Europe contributing to the colder pattern.  However in my opinion there is much uncertainty in the evolution of the PV beyond mid-January.

Impacts

The most important development, in my opinion, in the atmosperhic circualtion over the past week on the hemispheric scale has been the reversal of cold tropospheric polar cap geopotential height anomalies (PCHs) to warm tropospheric PCHs.   With the warming of tropospheric PCHs, cold temperatures have started to become more widespread across the NH continents.  Also the AO is predicted to be in an overall negative trend with the potential of the AO becoming strongly negative by the middle of January.  The strongest relationship between temperatures and the AO is northern Eurasia and the models are predicting cold temperatures to become more widespread across northern Eurasia including Europe and East Asia over the next two weeks.

Across North America the AO has its strongest relationship with temperatures in the Eastern US.  However here the forecast is more complicated.  Temperatures are predicted to turn colder this week but then become milder again even as the AO is predicted to turn more strongly negative.  No one index is a perfect predictor of temperatures and there are many instances of when warm temperatures were widespread across the Eastern US during a negative AO regime.

The negative AO trend and the predicted positive trend in Eastern US temperatures is not the only inconsistency between the model forecast and my own conceptual model of anticipating weather trends.  The model forecasts of warming temperatures in the Eastern US are also accompanied by the predicted winds around the stratospheric PV switching from southwesterly to more northerly.  This should favor temperatures turning colder in the Eastern US and not milder as predicted.

Finally I have been anticipating a PV disruption in the second and third weeks of January and so far the Global Forecast System (GFS) is showing little signs of that.   From the little of the European Center for Medium Weather Forecasting (ECMWF) that I see, it does look to me that the ECMWF model is somewhat more bullish on a stratospheric PV disruption than the GFS in the coming weeks.  Though admittedly the tropospheric wave pattern is not ideal for generating upward Wave Activity Flux (WAFz) or poleward heat transport and below I present an alternative interpretation of troposphere-stratosphere coupling more consistent with  quiet WAFz the second half of January.

In conclusion the forecast of colder weather across Northern Eurasia is consistent with the warming tropospheric PCHs and negative AO trend.  In contrast the forecast of a milder Eastern US is not consistent with these trends.  It is actually not that common for it to be cold across all of northern Eurasia, including Europe and East Asia and the Eastern US simultaneously even when the AO is negative, so a cold northern Eurasia and warm Eastern US does not bother me.  It is that the cold air will be widespread across the Eastern US and then while the AO is predicted to turn negative the temperatures are predicted to become milder.  I would not say that the models are wrong but rather I feel that greater uncertainty than normal should be attributed to the model forecasts in the medium range and beyond...".

Judah continues with his assessment of near-term up to 30 day+ conditions including an array of charts and diagrams. Please use the link that I show above for further reading.

BRIEF COMMENT:

Well his report is much more upbeat for coldies than I had anticipated! I have spent nearly 8 hours preparing my report and haven't had a chance to catch up with and examine this afternoon's model output which I shall do so after I've finished editing all this.

Arctic Sea Ice News and Analysis:

The last full monthly report was published on December 6th but please note that the current ice extent map and the comparison chart to the mean are updated daily and are always of interest. Here’s the link for the latest updates:

http://nsidc.org/arcticseaicenews/

The chart below shows the current extent of the sea ice (as on January 2nd) in relation to the long term means.

http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries_thumb.png

 

The recovery is still at record lows but after a slight blip a week ago it is getting very close to overtaking the previous low set during Winter 2012-13. I still believe that with the slightly colder forecast conditions up there for the short-term at least, 2016-17 will overtake 2012-13 soon. The Baring Sea and Kara Sea ice extent on our side of the Arctic has also been recovering much more quickly during December but is still well below average. The recovery is also evident across other parts of the Arctic, particularly the ice extent in Hudson Bay, around the Canadian islands and now around Greenland too with a very rapid increase during the North American very cold snap during last month (and another cold snap right now).

Last Winter the record strong Polar Vortex sent a roaring Atlantic Jet Stream right up towards the high Arctic which greatly restricted ice build-up for weeks on end in the part of the Arctic nearest to us. So far this Winter this has not been the case, although other factors are also at play. There has been considerable speculation as to how this low ice extent interacts with the teleconnections and how it might impact on broad northern hemisphere Winter patterns.

Arctic Oscillation (AO) 14 Day Ensemble Charts (updated January 3rd): 

The Arctic Oscillation, which is moving from neutral to positive this week goes negative during week 2 from around January 10th with many ensemble members going strongly negative by January 15th.

CAUTION:  this is in line with the current GFS model output but is liable to further fluctuations in line with changes in that model’s output. It does currently reflect a change to greater HLB in mid-January. Here’s the link for future reference.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao_index_ensm.shtml

...and here’s the current chart:

North Atlantic Oscillation (NAO) 14 Day Ensemble Charts (updated January 3rd):

The NAO is much more mixed starting off slightly negative, then trending positive and then back to neutral or weakly negative in week 2. Later on, the slightly NAO- is reflective of GFS modelling slightly higher pressure than average to our west and to our north and slightly lower than average further south. This is a mixed and weak signal with no dominant pattern (better to refer to the anomaly charts from Knocker and John for the time being). Here’s the link for future reference:

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

...and here’s the current chart:

Please note that both the AO and NAO charts I show are based on GFS ensembles so are indicative of their modelling and not the ECM and UKMO output.

MJO Ensemble charts:

Here are today's MJO ensemble charts for the big 4 (all updated on January 3rd) with the live links below should you wish to check any future changes. 

UKMO (7 day forecast): 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ukme.shtml

ECM (14 day forecast):

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ecmm.shtm

NCEP/GEFS (14 day forecast):

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ncpe.shtml

JMA (9 day forecast):  

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/jman.shtml

Please note that last Winter I reported on Kyle MacRitchie’s specialist MJO predictions which seemed to always differ somewhat from the big 4. I have been in contact with Kyle during the summer and he feels that his charts are not adjusted frequently enough and should not be compared to the others. So, unless Kyle improves his updating standards, I shall discontinue reporting on his predictions for the time being.

COMMENT:  A rather mixed picture but the 3 models (excl UKMO) that show week 2 changes do show a drift in the right direction towards the important phases 7, 8 and 1 (albeit with very little amplification) with a few of the ECM ensemble members now the most progressive. So, slightly encouraging but not nearly a strong enough signal to draw any more reliable conclusions as to whether the MJO will come to life and possibly assist with some greater HLB.

Northern Hemisphere Snow Cover:

I show animations for snow cover and sea ice changes. These are produced by the National Ocean and Atmospheric Administration (NOAA).  When you go to their site you can change the date range and look at the Autumn and Winter seasons and you can change the speed and pause on any particular day. These are brilliant, very informative charts and great to play around with. I’ve have re-set the links below to show the last 2 weeks from December 16th  to December 30th but you can change these again:

a) Animated Northern Hemisphere Snow Cover Changes (updated by NOAA December 31st):

https://www.ncdc.noaa.gov/snow-and-ice/snow-cover/nh/20161216-20161230

b) Animated Europe and Asia Day Snow Cover  (updated by NOAA December 31st):

https://www.ncdc.noaa.gov/snow-and-ice/snow-cover/ea/20161216-20161230

Please note that NOAA have only updated these charts up to December 30th and not to January 2nd  (probably due to the New Year’s holiday) and these last few days may be showing later tomorrow.

BRIEF COMMENT: 

There continues to be well above average snow cover over northern Asia and this has recently expanded southwards and south-westwards.. Much of northern Scandinavia continues to have decent snow cover but the south has lost most of its snow cover in the last few days (the high central plateaus usually have pretty complete snow cover for most of an average Winter). The snow cover currently extends to far eastern and north-eastern Europe but has receded from central Europe recently. North American snow cover had increased significantly during the very cold snap but has receded very slightly in recent days. The Arctic ice sheet has expanded quite quickly during the last few days on the Alaskan side but halted it expansion in the Baring and Kara seas (as described earlier) only to resume growth again from last week. The Hudson Bay has gone from almost ice free to completely ice covered during the second half of December.

Current Arctic Regional Surface Temperatures:

GFS – Northern Hemisphere Current Surface Temperatures for January 3rd 1900 (12z – 1300 T+6):

EDIT: Please note: My "work in progress" on pasting these charts has a long way to go! I wanted the  chart above to hold (or freeze) for the date and time shown above but it keeps updating with the most current one making my comments and readings below rather out of kilter. I think that I need to press the time shown to the left of the chart (T+6 for the above) before copying it. Ideally, I would want to show a completely current chart at the time of posting (T+0) which may well be available elsewhere - more homework for me! If anyone much wiser to all this can advise me, I would greatly appreciate a short PM. 

and here’s the link to live charts if you wish to view future changes (updated 4 times a day):

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=6&mode=9&carte=1

North Pole:  -24c to -28c (-28c).

Barents Sea/High Arctic:  -4c to -12c (-8c to -20c).

Scandinavia: south -4c to -12c (0c to -4c); north -20c to -24c (-4c to -8c).

Northern Siberia: -32c to -40c with a much wider area below -40c  (little change).

North West Russia:  -24c to -32c (-16c to -24c)

North-east Europe: -4c to -12c (-8c  to -16c).

Greenland: -16c to -40c (-16c to -32c).

Canadian Arctic: mostly -12c to -28c (little change).

Alaska: -4c to -12c (-8c to -16c).

Please note:  For land masses I have tried to focus on readings away from the coasts and away from any mountainous areas.   You can follow the trends by looking at the latest data at any time from now on. It is vital to note the time of day to take account of daytime/night time variations. So for like for like comparisons, for example the 1900 charts for each day should be available to view from the 12z (T+6) updates which are published around 1600 to 1700 or about 4 to 5 hours later.

Svalbard Daily “Maximum” Temperature Forecast for 10 Days:

Here are the links to the 3 Svalbard stations that I am monitoring.

Central/West Svalbard – Longyearbyen 28 m asl:   

http://www.yr.no/place/Norway/Svalbard/Longyearbyen/forecast.pdf

January 4th   -6c;    January 8th  -9c;       January 12th  -12c.

North-West Svalbard – Ny-Alesund:  

http://www.yr.no/place/Norway/Svalbard/Ny-Ålesund/forecast.pdf

January 4th   -3c;    January 8th  -15c;       January 12th  -10c.

Central South Svalbard – Sveagruva:   

http://www.yr.no/place/Norway/Svalbard/Sveagruva/forecast.pdf

January 4th   -11c;    January 8th  -15c;       January 12th  -13c.

Please note that the links above will update automatically at frequent intervals throughout the day. They are the Norway met office’s predictions. We need to be aware that these are only a forecast that is subject to change and I am told that the Arctic surface temperature forecasts are not completely reliable even at quite short range. 

BRIEF COMMENT:

The “maximum” temperatures fell to around -20c  during the second week of December and then recovered to around 0c around Christmas time but have fallen back again during the last week. Temperatures often rise briefly during a snowfall such as for January 4th before falling again when it clears. Overall, these temperatures are generally similar to last Winter but have trended a little below this month (compared to January 2016) but are still well above the 30 year means.

To put the above figures into context, here is a link to the main Longyearbyen site:  

http://www.yr.no/place/Norway/Svalbard/Longyearbyen/statistics.html

This shows monthly means and actual highest/lowest temperatures recorded during this winter and goes back further. Svalbard has been seeing “maximum” temperatures often running at 8c to 10c above their long term average throughout most of 2016. This has been the pattern for several years and is reflective of the warming Arctic and record low sea ice cover. The very recent trend has been slightly more encouraging with temperatures falling to slightly below their long term averages for 4 days in early December  which is the longest period of below average temperatures for about 3 years! Then maximum temperatures rose to around zero over Christmas are trending somewhat lower again now. They are predicted to be generally around    -10c to -15c during the first half of January. Should this coincide with one of the possible brief Arctic outbreaks predicted by some models (on and off) for mid-January, this could be useful for the UK. Slightly lower Arctic surface temperatures might be the difference between rain/sleet and snow in a marginal set-up for low lying areas further south (depending on the 850s and sub 528 dams)

Final Comment:

Most of the models, indicators and forecasts used in this report continue to reflect the very uncertain outlook. There are currently “some” slight indications of a colder spell just after mid-month but things might well swing quite significantly during the next few days. Judah Cohen's latest update (hot off the press after 2300 this evening) is much more bullish for coldies. I was going to say, overall, completely inconclusive but perhaps there are now slightly stronger indications of a "colder" pattern developing in our part of the world. Even if this does materialise, the timing, length and degree of cold are extremely uncertain at this stage.

Next Update:

Scheduled for Monday, January 9th when Judah Cohen’s weekly updates revert to their normal times late on each Monday evening.

Edited January 4, 2017 by Guest
To ensure that all the charts are showing, the links are working properly and to correct any typos

[snowbob]

Could today be the day the models start to play ball for the winter we all crave.

certainly seems to be edging that way since this mornings 0z runs.

slowly but surely.

is this the "murr" ment we have been waiting for.

[bluearmy]

1 minute ago, nick sussex said:

It going has been modelled at day ten for what seems like weeks! It crxpped all over my Christmas and meant I had to shelve my husky ride, the mountains look the worst I've seen since in January since I've been down here. I'm close to losing it big time if that wretched slug doesn't do one soon. As you can tell I'm just slightly irritated! lol

This time is different - this time we have all the ens suites in broad agreement and they have counted down from 15 days. We are now at day 10 on this cycle and we haven't fallen off yet. Previous examples thus far have not had Canadian ens with us.

[feb1991blizzard]

Hello, nice to see you Jan 1987.

 

[Dennis]

its a good blocking ..... there is a good chance to see it happen but some good signs out of the strato need too

Edited January 3, 2017 by Dennis

[bluearmy]

I can't go with that amount of amplification to Greenland but the overall themes through week 2 are pretty good on that run in respect of the ens suites. 

[Allseasons-Si]

Purely for fun,the pub is full tonight

[TEITS]

3 minutes ago, feb1991blizzard said:

Hello, nice to see you Jan 1987.

 

How I wish that to be true. The Jan 87 was a rare beast as the PV was sat underneath the HP. This is why the E,ly was so brutally cold.

[bluearmy]

Incidentally, there does appear to be some support for Steve's idea that the dropping system day 7 isn't followed by a slight rise in temps thereafter with a decent amount of eps members dropping the London temps down before the the expected colder spell post day 10

[snowbunting]

It seems the ECM, ensembles and GFS are moving towards a much colder mid month. The NAO looks like it will head slightly negative. 

Much better runs for cold lovers. 

[feb1991blizzard]

7 minutes ago, TEITS said:

How I wish that to be true. The Jan 87 was a rare beast as the PV was sat underneath the HP. This is why the E,ly was so brutally cold.

True but that chart I posted could easily deliver a proper dumping to you though, just a little kink in the isobar with -12c uppers would see to that.

[feb1991blizzard]

ECM ens trending slightly upwards at the end - always a bad sign.

[tight isobar]

@feb1991blizzard..

Why is a trending upwards a bad sign..in your opinion? ?

Ens flatter themselves sometimes..like some members!!!!

[karlos1983]

They look marginally better than this mornings imo 

More of a case of steady to be honest 

Edited January 3, 2017 by karlos1983