Model output discussion 25th Jan - The final third of winter beckons..

[Luke Attwood]

So when are u the ECM ensembles released

[PersianPaladin]

21 minutes ago, tomjwlx said:

+8 uppers into London at 216h so lets see how much support it has later!

Can't be discounted but seems quite extreme when most background signals point to a colder theme especially later in the month.

 

Personally I wouldn't mind that sort of weather. Would be a relief to the amount of colds and illnesses going around up here at least. Still, its a pretty plausible option given the persistent modelling of the PV lobe in Greenland; which will - if not somehow warmed-out by a change in general pattern - build heights in the Atlantic in an orientation that will end up bringing mild air over us.

 

Edited February 5, 2017 by PersianPaladin

[KTtom]

Very short memories here, how many times have people been celebrating ECM outputs + 168 hrs with no backing from other models, yet, now it doesn't go with cold it must be Correct?  It's been shocking post 144...as others have said, in this volatile winter, stick to the Met? 

[Duane S.]

Just now, Frosty. said:

It's unfortunate that every run is taken as gospel, I'm still very encouraged..wait for the Ecm 12z ensemble mean to give a better idea, it was very good this morning despite the op.

Indeed, there is a heck of a lot to be encouraged about. Anybody who likes cold and snow would be mad not to take today's runs (Ops and ENS included) as a whole. As always though, the concern is when the most recent Op run is the worst of the lot. I strongly suspect the EC ENS will show some support but not enough for us to be too concerned.

Then the 18z will come along and show it who's boss with a Cobra run to put Jan'87 in the shade!

[Summer Sun]

2 minutes ago, Luke Attwood said:

So when are u the ECM ensembles released

08:30 and 20:30 GMT

09:30 and 21:30 BST

[Methuselah]

Right then. Over the upcoming three-weeks or so, we are likely to experience very cold uppers + surface cold, warmer uppers but still with surface cold, and even some warmer surface-temps too...Isn't that just about what we should expect, from a continental flow? It's never going to be sub -10C uppers all the time!

[Daniel*]

It has to be an outlier surely the progression from 120 to 144 did not look right to me. The forum would descend into meltdown if that materialised even Tamara would be peed off.  

[Summer Sun]

Anyone who is not sure of the model update times please bookmark the below link

 

[Zakos]

7 minutes ago, Daniel* said:

It has to be an outlier surely the progression from 120 to 144 did not look right to me. The forum would descend into meltdown if that materialised even Tamara would be peed off.  

Thats a quite a pattern change in just 4 days, incredibly progressive from the ECM

 

The forum would fall silent I imagine after yet another tease. The short term is so promising, surely we can snatch something wintry from this pattern? heres hoping!

Edited February 5, 2017 by Zakos

[blizzard81]

The ecm really has been an attention seeker this winter hasn't it lol. A little like the gfs of old. It has teased with cold and snow paradise on and off all winter and the other models were having none of it. Now all the other major models are going for it but ecm doesn't really want to know. If it is correct tonight, it will go into the most hated model category for this winter lol.

[Guest]

Please note: I have copied this post across to the "in depth thread" should anyone wish to discuss any points that I have raised and share their views in a less frantic environment

 WINTER 2016/17 FULL REPORT No. 12 WITH FEBRUARY 5th INPUT

This is by far my most upbeat report of the whole winter (whatever any of the 12z model output might say!)

Brief Review Of The Last Week:

The widely predicted change from the cold continental influence to the more unsettled Atlantic influence was completed early in the week but not without further cold days in the north and north-east at first. The named storms, indicated on much of the model output a week ago, did not reach us but took a more southerly track into France where they named one storm  “Leiv” but fortunately the severest damage was restricted to a very small coastal region in western France. The following storms were less intense.  We were on the northern edge with some rain and briefly some stronger winds in the south and south-west. Although temperatures have recovered to some extent they have (mostly) only slightly exceeded normal on a few days and were generally in single figures with even a little wintry precipitation on higher ground in some parts.

The Current and Short Term Position:

I felt that this milder spell would be brief and kept a careful watch on the European cold block which I have said time and again during the last month has been consistently under estimated by almost all the models. I believe that this is still being under estimated and this time it will greatly assist us in the feed of deeper cold air into the UK by next weekend. In fact, I felt so strongly about this that I started a “Daily European Temperature and Pressure Watch” three days ago. My latest update was posted this morning (see page 92).  The cold block was only pushed slightly eastwards into western Asia. Much of central and eastern Europe only briefly saw temperatures rise slightly above freezing (for a couple of days).

The UK Atlantic spell is being cut short. Fronts will be stalling across the country during the next three days as a Scandinavian HP takes hold.  There may even be a little snow as the fronts return westwards before they fizzle out. Right now, pressure is building strongly from north-west Russia and is already ridging into Scandinavia – just look at my live pressure chart on page 92 and compare that to the 0650 chart. The deep cold is also steadily intensifying in north-west Russia and moving south-westwards into northern Scandinavia. The sub -20c pool of surface cold (some is nearer -30c) and sub -20c 850s are also expanding and moving steadily westwards and south-westwards. I believe that the transition may well be even faster than currently predicted with colder weather installed by mid-week. I also think that there is a good chance that the small area LP that moved across south-west England today will move away into France. Then the fronts associated with the following larger area of LP tomorrow may not make much progress into the UK and there might be a good chance of a new small LP forming on the warm front or near the occlusion which could move away south-eastwards and further undercut the block, introducing easterlies further south into the UK a day or so sooner.

I demonstrated the predicted development of the Scandinavian  HP in another post yesterday (see page 84) where I used all the Met Office fax charts. I had noted that their latest charts (which were issued several hours ahead of the 12z model output – they always give an advance clue to any likely near term changes) were showing the HP being maintained further north and west over Scandinavia and with a better alignment for the easterly on its southern flank. Some of the models are still struggling with the all important detail on this. I indicated this morning that there were already several undercutting LPs propping up the HP. Okay,  I had better post the two live charts now to make my points clearer (but just take another look at all the charts on page 92 to fully appreciate the extent of today’s changes):

EUROPEAN "LIVE" PRESSURE CHART                       EUROPEAN "LIVE" TEMPERATURE CHART

                                 

At this stage, my take on this is that the Scandinavia HP will not sink southwards, at least for quite a few days. I also believe that with this and the under estimated depth and extent of the cold pools (upper and surface cold) that conditions will turn somewhat colder across the whole of the UK sooner than much of the recent model output has suggested.  I do note that the 0z output has mostly upgraded the colder uppers. I am writing this part of my report at 1330 and by the time I post it this evening, the 12z output will have rolled out.  I am expecting further upgrades over the next few runs but perhaps still with the odd single run/single model set back. The models mostly still need to factor in the current extent of the cold and as they update they should reflect these changes in the D3 to D6 range.

Now, I am not trying to score points over anyone (and it would foolish to try to take on the models for any extended period) and I may be wrong about this but let’s look at some more evidence. I noted an interesting point that @johnholmes raised several days ago which I completely agree with. The strength and persistence of HP and/or cold blocks is frequently under estimated by the models. In fact I would say that this is often one of their most serious faults or shortcomings and presents huge timing issues and even leads to quite a different outcome on occasions. In the days when forecasters did not have access to computer models, satellite imagery and all the other modern tools, they often had difficulties in assessing the longevity of these blocks. Much of their forecast was based on pure experience and using analogue charts alongside the current data. As John says, it is amazing that these blocks still present such forecasting difficulties.

Many on here have said, easterly airstreams have been much rarer in recent years. Back in the 1960s to 1980s they were so much more common. Not just in cold winters but we usually saw several of them even in predominantly mild winters. I can recall a great many examples of all sorts of types of easterlies but this is not the time or the appropriate thread to list them now. In broad terms, the most important component was “usually” the Scandinavian HP. Its position, orientation and how it developed was always so important. Some develop as a temporary extension of a Siberian HP. Some develop in situ, often after an Arctic incursion, when the LP fills up quickly and HP forms over the residual surface cold. Some are transient features and some stick around for days or even weeks on end. Some form when there is no cold pool to tap into. I recall a few easterlies with temps hardly below average. Some produce long periods of cold to very cold but completely dry weather. Some produce a few snow showers on exposed coasts but nothing more than a few flurries inland. A few produce much more convective conditions with rather heavier snow showers often merging into longer periods of snow. Isolated cold pools (those that have broken away from the main cold lobe, like the one indicated on one of the GEM runs two days ago (that disappeared on their next run), small disturbances and troughs can produce snowfall, sometimes developing quite unexpectedly.  Streamers can form in the more favoured downwind well aligned spots (like the “Thames Streamer” on a direct easterly flow) and produce many hours of almost continuous snow showers with significant accumulations. There can sometime be more general snow events when Atlantic LPs and their attendant fronts come up against the cold block. Down here in the West Country there have been a number of severe blizzards when stalling fronts undercut the easterly or south-easterly flow. These are rare events but can turn up in mostly mild winters (such as February 1978) as well as in severe winters (with multiple events in 1947 and 1962-63). Sometimes an easterly is swept away rapidly by the Atlantic (probably with the Jet Stream powering up with a more direct attack). Sometimes a LP over Biscay or France veers the flow to the south and pulls in much milder air.

So what sort of easterly will this one be and will it deliver any snow? Unfortunately, the answer is that I do not know for sure but there are some very positive signs. Factoring in some of what I’ve just mentioned, I am very encouraged in the way that this Scandinavian HP is developing. This is from the north or north-east into Scandinavia. There is already a good supply of surface cold. This is now being topped up with even deeper cold as I have already shown. HPs often sit over some of the coldest surfaces available. I feel that there is an excellent chance that once the HP sets up over northern Scandinavia, that it will maintain a similar position for quite a few days.

The next thing is the LP areas on the southern flank. The very latest position on the live pressure chart shows another really encouraging sign – the central European LP is already helping to re-orientate the HP. I think that within 24 hours it will be far more on an east/west or east-north-east/west-south-west axis. This means a more direct easterly. The strength of this flow will be determined by the intensity of the HP and how close are the LP(s) on its southern flank.  The increasingly cold air should then filter south-westwards in this flow.

The south of the UK in particular may well be far enough away from the HP to the north-east to encourage some convective activity. If we can get sub -10c uppers in, then things could start to get much more interesting. For now, I would say just some snow showers on exposed east coasts but all to play for in the finer developments during the next few days.

Next Weekend and Into Week 2:

So how long will this last for and just what can go wrong. I know that some on here like to be more cautious and it can be wise to manage expectations to avoid future disappointments. Others can get taken in by all the ramping with the very bests charts greatly outnumbering the less goods ones being posted (I wonder why!). After all the disappointments we have seen so far this winter as well as in several recent winters it would hardly be surprising to see quite a few members taking a sceptical view. I believe that this will be a rare occasion when things might just go right for us coldies.

This has been a highly unusual winter with persistent blocking restricting any Atlantic influence to the minimum. Blocked winters usually have prolonged cold spells. The vast majority of the blocking this winter has been MLB. This has allowed for some exceptional cold over Europe but we have mostly been just on the outer edge of it. There has been a highly anomalous area of  HP very close to the UK for much of the last three months. Several posters have said if only we could have the HP a little further north. Well your wishes are about to be granted! I believe that there is now an excellent chance of HP being located to our north-east and later to our north or north-west for much of the next six weeks.

Let’s have a look at the Jet Stream. The main arm has taken a more southerly track recently and the northern arm has broken up with a returning flow circling Scandinavia (which may help to maintain the HP or conversely, the HP is partly deflecting the flow of the Jet.

Northern Hemisphere Jet Stream – Current Position:

                         GFS 12z T+6  

          

Moving on to D6, let’s have a look at several cross model Jet Stream charts.  The main arm continues to be deflected to our south. The southern arm drives through the Mediterranean and south of most of Europe. This should carry LPs systems along that path and this will also help to underpin the HP further north.

Northern Hemisphere Jet Stream for Sat 11th Feb – 0100 (with adjusted times to provide an accurate comparison):

                        GFS 6z  T+144                                           NAVGEM 6z +144                               GEFS ens mean 6z T+144 

                   

Another useful indicator for assessing the likely future strength of the Jet Stream in the Atlantic is the thermal contrast between the eastern USA and the adjacent ocean. Right now and for at least the next week much of the USA will continue to have an unusually mild period. Canada is pretty cold but it rapidly turns milder further south. So, nothing here at all in helping to power up the Jet Stream.

Northern Hemisphere Current 2m Surface Temperatures                                                              Northern Hemisphere Current 850s

                                GEFS ens mean 12z T+0                                                                                                                  GEFS ens mean 12z T+0

                                                                                                                             

Northern Hemisphere 2m Surface Temperatures for 1300 Sat Feb 11th                         Northern Hemisphere 850s for Sat Feb 11th – 1300: 

                                         GFS 12z T+144                                                                                                                       GEFS ens mean 12z T+144           

                                                                                                                     

I have seen several poster’s concern over the chance of an Iberian LP drifting northwards over France and pulling in milder air with it. If the southern arm of the Jet continues to blow strongly through the Mediterranean there would seem to be a slim chance of this. In my experience, it is the slacker flows that can be prone to this. Even here, there are some examples of the milder air not being able to penetrate the surface cold and the warmer air is lifted over the cold which can produce far heavier snowfall or occasionally freezing rain. I call these events  “cold southerlies”. They occurred repeatedly in the two epic winters of 1946/7 and 1962/3. In fact most often in the two Februarys. I’m not saying that the 2017 cold spell will be anything like those two winters but entrenched deep cold will take an awful lot to shift it – not a gentle push from the south.

A Brief Look Further Ahead:

I have not yet even mentioned the stratospheric changes and the multiple warmings in the Arctic.  As I said in my report last Sunday (and repeated in several of my updates during the week) there was a good chance that even if the first warming fails to produce a true easterly that there would be one or two further opportunities. I was very reassured to see the latest updates from several of our strat experts like @chionomaniac that the PV should be split for a much longer period. In fact it may well be shattered! The MJO (see later) is predicted to enter its key phases through 6, 7,8 and 1 in the 10 to 15 day period. @Tamara, in her update today, maintained her view that the key background signals should all assist with much greater HLB. 

The result of this could be twofold, both are cold outcomes - either maintain and strengthen the existing Scandi block or encourage height rises towards Greenland with a broad Arctic flow established. In our longest cold spells we have sometimes seen several switches between easterlies and northerlies and back again. There could be a brief milder interlude during any transition and all the models have been struggling with this in terms of timing, extent and how long will it all last. I am going to stick my neck out and say that it will remain cold for the rest of the month (possibly well into the first half of March too) and it will be very cold for quite long periods. How much snow we might get is very difficult to for anyone to predict but the longer the cold spell continues the greater the chances. I am still very optimistic for the initial easterly to produce at least some of the white stuff.

Can it all go wrong – yes it can but I feel that this is our best chance in four years for a memorable cold spell and there is so much positive evidence in favour of it.

Now on to my routine coverage.

Arctic Sea Ice News and Analysis:

The last full monthly report was published on January 5th (next one due very soon). This is a fascinating read and includes a review of the whole of 2016. 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/

This chart shows the current extent of the sea ice (as on February 4th) in relation to the 30 year means.

Source: National Snow and Ice Data Center (NSIDC)

The “rate of recovery” during December was very close to a record and there has been a continued recovery (with several pauses) during January but, despite this, the overall ice extent is still at record lows and remains just below the previous low set during Winter 2012-13.

Arctic Oscillation (AO) 14 Day Ensemble Chart:

Here's the link to the daily charts:       http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao_index_ensm.shtml

...and here’s the current chart which updates automatically each afternoon:

Note for newbies: The AO index reflects the amount of HLB in the Arctic. A positive +AO reflects very little HLB and a strongly +AO reflects no HLB anywhere in the Arctic. A negative –AO reflects some HLB and a strongly –AO reflects substantial HLB with more intense high pressure and/or more extensive HLB in various parts of the Arctic. This index produced by NOAA is based upon GFS model output and will fluctuate in line with that. Although ECM produce similar data based upon their own output this is not one of their “free-to-view” charts for public consumption.

COMMENT (relating to the AO chart above when it was showing February 4th data - it updates automatically each afternoon):

The Arctic Oscillation is currently negative and many ensemble members go into much stronger negative territory into week 2 (the strongest for the whole winter) but a smaller number of members trend back towards neutral. This reflects the GFS model uncertainty around D8 to D12. A possible switch to HLB and a northerly, a continuation of the Scandi HP or a breakdown  with a milder Atlantic influence.

North Atlantic Oscillation (NAO) 14 Day Ensemble Chart:

Here's the link to the daily charts:                 http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.shtml (click on the small chart there)

...and here’s the current chart which updates automatically each afternoon:

Note for newbies: A neutral NAO index reflects the close to average state of the mean sea level pressure patterns or the “climatological” norm in the North Atlantic. This would equate to the anomalous high pressure in the south, particularly around the Azores and low pressure stretching from off the eastern USA seaboard in a wide band running north-eastwards to the east of Newfoundland, east of Greenland and through Iceland. A positive +NAO occurs when these patterns are stronger than usual (eg: the Azores high is more intense or more widespread and/or the Iceland low is deeper or more widespread than usual). A negative –NAO reflects a weak Azores high and/or less intense Icelandic low pressure. A strongly –NAO would reflect a reversal of the normal patterns with relatively low pressure in the Azores and high pressure further north towards Iceland. A “west based –NAO” (talked about recently) is when the pressure is higher than usual in the western Atlantic such as around the Newfoundland area). An “east based –NAO would indicate higher pressure than usual in our part of the Atlantic. This index produced by NOAA is based upon GFS model output and will fluctuate in line with that. Although ECM produce similar data based upon their own output this is not one of their “free-to-view” charts for public consumption.

COMMENT (relating to the NAO chart above when it was showing February 4th data - it updates automatically each afternoon):

The NAO is currently positive and most of the ensemble members trend gradually towards neutral but remain slightly positive. Although we have the Scandinavian block much of the Atlantic is still dominated by LP. The NAO is not particularly important at this stage. If the block moves further west, we may see a slightly negative east based NAO later on.

MJO Ensemble charts:

Here are today's MJO ensemble charts for the big 4 (all updated on February 4th) + Kyle MacRitchie’s modified chart (by request following recent discussions) with the live links below should you wish to check any future changes: 

               UKMO   (7 day forecast):                       ECM (14 day forecast):                     NCEP/GEFS (14 day forecast):                 JMA (9 day forecast):                         Kyle MacRitchie (30 day forecast):

         

 

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

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

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

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

Kyle MacRitchie   https://weatherandvines.com/?page_id=140                  and his explanatory notes and further guidance:     https://weatherandvines.com/?page_id=128

COMMENT (relating to charts showing February 4th data - they update automatically each afternoon):  What an amazing set of charts – a full house! The big 4 and Kyle MacRitchie all show the MJO entering the keys phases of 7,8 or 1 at very good amplitude. The best signals, I think for several years.  A few of the ensemble members go off the chart in phase 8! This is perfect timing and along with the second (and possibly third) warming events should greatly assist with considerable HLB as we move through week 2.  Over to our experts for a deeper analysis.

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 go back over 10 years. 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 January 21st  to February 4th but you can change these again on the site:

a) Animated Northern Hemisphere Snow Cover Changes (updated by NOAA February 4th):

https://www.ncdc.noaa.gov/snow-and-ice/snow-cover/nh/20170121-20170204

....and here is their current chart:

b) Animated Europe and Asia Day Snow Cover (updated by NOAA February 4th):

https://www.ncdc.noaa.gov/snow-and-ice/snow-cover/ea/20170121-20170204

....and here is their current chart:

COMMENT: 

Part of central and much of eastern and south-eastern European is still snow covered. There continues to be well above average snow cover over northern Asia and this has expanded even further southwards and south-westwards – in fact it is quite exceptional. Scandinavia is fully snow covered, except the south of Sweden (the high central plateaus usually have pretty complete snow cover for most of an average winter). The extensive snow cover over North America has declined during the recent much milder conditions and this is likely to continue during the coming week or so

The extensive snow cover over west Asia, Russia, eastern Europe and Scandinavia is another very important piece in the jig-saw as far as our forthcoming cold spell is concerned. This should greatly assist in getting the deeper surface cold in and maintaining very low temperatures for much longer – strengthening the block further.

 

Current Arctic Regional Surface Temperatures:

GEFS ens mean– Northern Hemisphere Current Temperatures for February 5th 1900 (12z – 1300 T+6):

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=1&carte=1

Here is my selection of Arctic Regional Temperatures:

The the previous readings from my last full report are shown in brackets alongside

North Pole:       -20c to -24c   (-20c to -28c).

Baring Sea/High Arctic:    -16c to -24c  (-8c to -16c).

Scandinavia:  south  -4c to -8c  (mostly -4c);  north  mostly -8c  (mostly -4c).

Northern Siberia:    -32c to -40c   (-24c to -40c).

North West Russia:     -16c to -20c  (-12c to -24c)

North-east Europe:     0 to -4c   (-8c to -12c).

Greenland:           -16c to -32c   (-20c to -40c)

Canadian Arctic:     -24c to -32c (-16c to -32c).

Alaska:      -12c to -20c    (-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 together with a summary of D1, D5 and D9 values:

Central/West Svalbard – Longyearbyen 28 m asl:   

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

February 6th    +3c;            February 10th  +1 c;            February 14th    -5c.

North-West Svalbard – Ny-Alesund:  

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

February 6th   +2 c;            February 10th  +1c;            February 14th    -5c.

Central South Svalbard – Sveagruva:   

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

February 6th    +2c;            February 10th   -2c;            February 14th    -8c.

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:

Temperatures have risen just above freezing during the last few days with one of the warmest periods of the winter. This followed one of the coldest periods in the previous week (even below the 30 year means). The southerly winds brought quite a bit of snowfall with more to come. It is only after next weekend that temperatures are set to fall again. 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.

Final Comment:

As I’ve already said, I am extremely positive about the forthcoming very cold spell. I feel that there is a good chance that this will last for at least 2 to 3 weeks and perhaps well into March. Now will I be eating humble pie next weekend – I do not think so!

Next Update:

My next full weekly report should be on Sunday evening, February 12th.

 

Edited February 7, 2017 by Guest
Correcting typos and to ensure that all the links and charts work properly.

[Banbury]

32 minutes ago, Stu_London said:

Shocker of an ECM for cold lovers.

Could be on the golf course sooner than I thought if it were to verify

 

ECM wont be that warm , unless your ok with mittens and a scarf when golfing it

[Duane S.]

The MJO plots show consistent and continued belief that we are going to have serious help from the Pacific here. This does not tie in with the ECM Op. Unless the model is working off a serious disconnect, which is not how I see it.

 

Even the Canada is coming around to the idea.

 

The Japanese model will need a new scale if it carries on like that!

 

Edit: I see BB63 has beaten me to it with the MJO plots. What a great post once again from him!

Edited February 5, 2017 by s4lancia

[Allseasons-Si]

The gfs showing a split of sorts at 212hrs then another warming taking place at the end

[nick sussex]

The UKMO at T168hrs has the high further north, looks like a kink in the flow has worked westwards and looks much better than the ECM:

https://ruc.noaa.gov/hfip/tcgen/

[snowflakey]

2 hours ago, Captain Shortwave said:

The second half of this week onwards looks to be a real nightmare to forecast, you could probably not even be able to get a reliable forecast even at 48 hours out looking at how the cold pool could interact with various other players. A big snow event could crop up if these cold pools move in a favourable manner or we could end up mostly dry with a few flurries. A fascinating and potentially frustrating week ahead by the looks of it.

Just a couple of charts of winners

UKMO

   

Snow showers in the north east to start, possibly becoming more persistent and become more focused in the south.

GEM

    

A slow moving band of snow could move in from the continent, some very cold air sitting over Holland.

There isn't really any consistency in the modelling of that cold air after it moves towards Scandinavia initially, I am feeling like we will be pulling the one armed bandit with every operational here to see whether we get a hit.

 

Just love to see those light green hues in the middle of a high pressure (500 geo pot), indicating some serious cold.

[Summer Sun]

Plenty of snow potential from UKMO extended

ECM's at the same time

[Stephen W]

8 minutes ago, s4lancia said:

The MJO plots show consistent and continued belief that we are going to have serious help from the Pacific here. This does not tie in with the ECM Op. Unless the model is working off a serious disconnect, which is not how I see it.

 

 

But surely there are other factors in addition to MJO which are impacting and perhaps overriding the MJO signal.  There must be as far as ECMWF is concerned. 

Edited February 5, 2017 by Stephen W

[warrenb]

Having watched the countryfile forecast,  the synoptic charts they showed for the blocking had it well north of where the ecm has placed it for next Friday 

[SMU]

UKMO says no to ECM with snow for many...

[BurwellWeatherWatch]

looking at the models and going by the evidence from the posters who are vastly more knowledgeable than myself : it certainly seems that ECM 168 is unlikely to verify in that extreme format. There may not necessarily be snow-mageddon, and a cross-model blend of the more mainstream stuff may leave us cold and relatively dry.

but it's assured to get very cold as the week progresses and that is a good start on the path to something more interesting than we've had so far. A nice 80s feel about it all.

Some amazing contributions in here tonight and inspiring to read such well thought out posts. On the other hand a great deal of forum willy-waving as to who can paint the most apocalyptic vision of ECM168: "I'll get the barbecue out if that verifies."

"No I'll be doing the barbecuing in my pants while polishing my surfboard" -

all a bit tedious! (ESP as Ecm 168 would actually be V cold at surface)

Edited February 5, 2017 by BurwellWeatherWatch

[Ali1977]

1 minute ago, Steve Murr said:

UKMO says no to ECM with snow for many...

Oh yes - decent snow event there!!

[Man With Beard]

46 minutes ago, Iceberg said:

 

 

Pretty clear what's happened here- that shortwave off the coast of Norway is the same one that the UKMO and GEM have over the UK. Basically, the ECM has spun it round the high so quickly that it catches up the vortex to the north, fuses with it and sinks the high.

This to me is an unlikely scenario. These disturbances rarely travel so far without hitting a barrier of some sort. It's a bit like went a monster cold pool is forecast to get from Russia to the UK in one run, then nearer the time it gets held up by a kink in the flow and never makes it.

This shortwave would have to run absolutely perfectly around the high to catch the vortex in time to make the rest of the run happen.

If looking for a middle ground tonight, the GFS is fairly even between UKMO and ECM.

[Chris.R]

@Bring Back1962-63

Absolutely brilliant post! Also please keep those daily temperature watches going, they are fascinating. 

[blizzard81]

6 minutes ago, s4lancia said:

The MJO plots show consistent and continued belief that we are going to have serious help from the Pacific here. This does not tie in with the ECM Op. Unless the model is working off a serious disconnect, which is not how I see it.

 

Even the Canada is coming around to the idea.

 

The Japanese model will need a new scale if it carries on like that!

 

Edit: I see BB63 has beaten me to it with the MJO plots. What a great post once again from him!

The question we have to ask ourselves is what is the ecm seeing that the other models aren't? What unsettles me is that the ecm is still the best verifying model out there. Surely one of the reasons for this is it's ability to pick up on certain things quicker than the other models. Maybe that's what has happened today and the other models are playing catch up. I guess we will know one way or the other when the 00z runs roll out in the morning.