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Model output discussion 8th Feb - Cold for now, but then what?


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Still a chance of some brief snow later in the week according to the Gfs 12z and then a cold snowy westerly in FI..hopefully we will have some deeper cold to tap into during the first half of March.:)

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12_195_preciptype.png

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Evening All- ive been offline for a week taking a little break- monitoring the progress of the strat mainly- Things are homing in nicely now on the second SSW of the season ( a final warming

the possibility of a prolonged cold spell towards late November the possibility of a prolonged cold spell towards early December the possibility of a prolonged cold spell towards mid December the poss

Rather disappointing that the obsession over cold and snow excludes some fascinating weather over the next 72 hours. This is the deepening low, not yet even formed. It is due to begin to develop in th

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This evening's gfs 100mb charts not at odds with the 500mb anomaly with the trough mid Atlantic and a suggestion of some nice ridging over the UK at the end of the period

2017021912_f240_200.nonenonehghtnonenone_g201_mrf.thumb.gif.9ae9820a9cba66da128513a17473d147.gif2017021912_f384_200.nonenonehghtnonenone_g201_mrf.thumb.gif.bab966ef281f5d4d18f8e8f72d10fd15.gif

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52 minutes ago, Steve Murr said:

Evening All-

ive been offline for a week taking a little break- monitoring the progress of the strat mainly-

Things are homing in nicely now on the second SSW of the season ( a final warming ) - initially the GFS modelled this & the ECM wasnt on board- however as time has ticked by the ECM has followed suit -

the 10HPA values now set to land at 0m/s around the 24th so this coming Friday - 

Also the 30HPA responding as well

IMG_2879.thumb.PNG.0a4668b327a984da47035b3e8fcb5de9.PNGIMG_2880.thumb.PNG.5a1d08159d9351b280e6df66d2a302ac.PNG

So whilst there isnt to much in the way of tropospheric response just yet - all be it a fleeting Northerly this week- I still expect one last roll of the dice before winters finished- similarly to March 13 it looks cold !! 

So technically March may be spring however the window for Winter is still open- 

GFS now touting significant changes over the pole around day 12-13 on a similar pathway to a propergating SSW...

watch for the AO start to tank in the midterm from this week...

S

 

I'm willing to bet march 2013 isn't repeated 4 years later.

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WINTER 2016/17 FULL REPORT No. 14 WITH FEBRUARY 19th INPUT

Outlook: From Warm To Cold To Mild This Week – Then What? There Are Some More Encouraging Signs For Coldies Into Early March

My last full report was on page 21 of this thread.

Apart from my routine features in this report, I shall include a special focus on the warm interlude predicted for early this week and put it into context

Brief Review Of The Last Week and the Current Position:

Last Sunday, after a little more snow in places the short cold spell was already losing its grip with milder air pushing up from France. The Scandinavian high pressure (HP) sunk steadily southwards and now lies over southern and central Europe in a broad band stretching to the east and ridging westwards linking up to an extension of the Azores HP. Temperatures generally recovered to nearer normal, slightly above on some days but with slight frosts on several nights and some fog patches. There were a few short periods of mostly very light rain moving from south-west to north-east.

The European cold block has weakened considerably and has been steadily eroded by westerly winds. The deeper cold has been pushed back into western Asia and Russia. Northern Scandinavia is temporarily colder again with a northerly incursion up there. Daytime temperatures have risen above freezing even in much of central Europe but night frosts have continued away from the far west of Europe. This can be seen on the European surface temperature charts below (0650 close to minima and 1250 close to maxima):

                CURRENT “LIVE” TEMPS FEB 19TH                            FEB 19TH  0650 TEMPS                                  FEB 18TH 1250 TEMPS

                   temp_eur2.png                     temp_eur2-06.png                   temp_eur2-12.png

For the next few days we can look to our west and south-west for our upcoming weather.

The Short Term Position and the Warm Interlude:

The HP to our south-west is bringing in a tropical maritime flow originating from between the west of North Africa and the Azores. This will flood across the country during Sunday night and into Monday. Temperatures will rise well above normal and reach unseasonably high values in the south. A wide area of central southern, the south-east, East Anglia and the Midlands will see temperatures approaching or exceeding 15c on Monday. The air stream will be very moist with some low cloud and hill fog and more generally cloudy. Any areas which see the sun break through may see temperatures several degrees higher but perhaps, not quite as extreme as forecasts suggested several days ago. Favoured spots might be to the lea side (north-east) of any slightly higher ground such as towards the north Kent coast and around Gravesend. A wider area from north London through Hertfordshire into south Cambridgeshire might also see the highest values tomorrow afternoon.  It may be hit or miss for maximums up to 17c (possibly even a degree higher). The Arome 0z chart below is a typical representation and gives a very rough idea of the maximum temperature distribution over southern England for the 12 hours up to 1900 tomorrow.

                AROME 0z T+42 MAX TEMPS

             arome-31-42-0.png?19-05   

There has been the usual misreporting in the press and several rather inaccurate comments on this forum in the last few days. The Daily Mail said that temperatures would reach 18c and the highest for over 160 years. They may be right about the temperature but not the record. This value has been exceeded on at least 8 occasions in those 160 years and 19c has been exceeded on 3 occasions. The long standing record “was” on 27th February 1891 with 19.4c in Cambridge but that was exceeded during a memorable warm spell from 7th to 15th February 1998. Temperatures rose above 15c on 8 consecutive days somewhere in the UK.  On February 13th the maximum exceeded 19c at a number of locations in southern England and the Midlands.  The new February record was broken with 19.7c at Greenwich, 19.6c in Worcestershire and 19.5c in Somerset. This spell was all the more remarkable for being in the first half of February as well as for its longevity. 1997-98 was the time of the “super El Nino” – the strongest on record (almost matched in 2015-16). More tentative early records suggest that 1891 was also a strong El Nino year (Wikipedia with links and “confirmation required” entry; NOAA’s records only go back to 1896).  Interestingly both the 1891 and 1998 warm spells  were followed by a very cold spell in early March. There was no SSW or any warming events in 1997-98 and records do not go back to the 1890s. 

It may not be too long before we see 21c (70f) exceeded in February if the current warming continues (although the trend “may” be reversed during the next 30 or so “Maunder Minimum” years but that’s another discussion). There was another noteworthy and remarkable warm spell in early March 1948.  That saw 23.9c at Wealdstone, Middlesex (near Harrow in NW London) and even 23.3c  at Cromer (on the north Norfolk coast). Higher temperatures have all occurred towards the end of March (25c reached in 1929, 1965 and 1968) but nothing comparable in the first half of March. All these events involved tropical maritime incursions and HP very close to our south-west, south or south-east and followed quite prolonged dry spells. Very high values in December and January are usually confined to the fohn effect with adiabatic winds on the lea side of mountains such as at Rhyl in North Wales downwind from Snowdonia.  By mid-February the sun can just have enough strength to burn off the low cloud and warm the surface slightly. In the charts below, I compare the current pattern to the two previous February events and the March event from the archives:

           GFS 6z T+30 Mon 1300                                 NCEP 13.2.1998                                    NCEP 27.2.1891                                      NCEP 9.3.1948

    gfs-0-30.png?6?6        archives-1998-2-13-12-0.png       archives-1891-2-27-12-0.png       archives-1948-3-9-12-0.png

Later This Week and Through to Next Weekend:

At the time of writing (1100 Sunday) the tropical air mass sourced from the far south is predicted to be cut off during Tuesday with the HP slipping further south and LP to the north becoming more dominant and introducing more of a westerly flow. If it had persisted for a couple more days we may have seen the 13th February 1998 record being challenged. It looks like we are set to enter a much more changeable period with a succession of LPs running mostly to the north of Scotland. Some of the models “had” been showing a brief Arctic incursion for around Friday into Saturday and even a little snow but this has mostly been watered down into an even briefer period. So, perhaps less than 24 hours with either a polar maritime or Arctic maritime sourced flow, an Azores ridge and another LP to follow. The period from D3 to D5 can be summed up as some quite short periods of rain, heaviest in the north, moving through quite quickly in the brisk and at times quite strong winds with drier, clearer or brighter interludes in between. It will be mostly rather mild but far less so than tomorrow with shorter colder incursions perhaps with a frost if they occur overnight. Any snow looks like it will be confined to showers over northern hills and mountains during the colder interludes.

Of course the minor details might change so let’s take a look at the position for next Friday with one of my cross-model checks.

Northern Hemisphere Pressure for Friday, February 24th at 0100 (with adjusted times to provide an accurate comparison):

                 GFS 6z T+114                                  ECM 0z T+120                                  UKMO   0z T+120                             GEM 0z T+120                               NAVGEM 0z T+120   

 gfs-0-114.png?6?6  ECM1-120.GIF  UW120-21.GIF  gem-0-120.png  navgem-0-120.png?19-07

        JMA 12z Feb 18th T+132                  GEFS ens mean 6z T+114             Met O Fax 12z T+120 for 1200 Thur  Feb 23rd  (latest available) 

  J132-21.GIF  gens-0-1-114.png                               20170218.2301.PPVO89.png

The main variations are the strength, timing and exact track of the LPs and the extent of the Arctic incursion. The broader pattern is generally agreed by the models but the finer detail is still somewhat uncertain.

Into Week 2 and Beyond:

The unsettled spell looks like continuing for much of this period too. There still seems to be some debate on the likelihood and timing of the final warming event. Going by the recent posts and comments on the strat thread it seems possible or perhaps probable that we might be looking at some changes impacting around the second week in March. There are hints of some HLB being picked up in distant FI with the GFS showing a possible Svalbard HP or Scandi HP by around T360 to T384 (D15-D16).  That’s a long way off but a much colder spell before mid-March cannot be discounted.  I will pick up on northern hemisphere and Arctic temperatures later in this report where there are some much more encouraging signs.  In the meantime, let’s have a look at the Jet Stream.

Northern Hemisphere Jet Stream – Current Position:

                              GFS 6z T+6  

            gfsnh-5-6.png?6    

The Jet Stream is going through a transition but continues to be split from North America through the Atlantic and into southern and central Asia.  The lower arm takes a very southerly track through North Africa, still well south of Europe and through the Middle East into south-west Asia. The northern arm has strengthened during the last week and is particularly strong in the Pacific (where the two arms rejoin and this is producing the unusually heavy rainfall that is relieving the two year drought in California). It’s still slightly meandering and fragmented in the Atlantic where it moves north-eastwards and approaches the UK from the north-west.

Northern Hemisphere Jet Stream for Sat 18th Feb – 0100 (with adjusted times to provide an accurate comparison):

                    GFS 0z  T+138                                             NAVGEM 6z +138                         GEFS ens mean 12z T+132 (updates?)                            JMA 12z Feb 11th T+156

    gfsnh-5-138.png?6               navgemnh-5-138.png                  gensnh-0-3-132.png                      JN156-102.GIF                                               

Moving on to D6, let’s have a look at several cross model Jet Stream charts (above).  All the models show the northern arm taking charge and firing through North America and right through the UK. The JMA shows it rather stronger than the other models, the NAVGEM the weakest with the GFS and GEFS ens mean in between but still showing a rather meandering path across the Atlantic. The southern arm continues on a similar very far south track but is weakening across the Atlantic. As it moves out of Asia it moves northwards in the western pacific to become the main arm where it’s at its strongest. There is a break away loop circling Alaska. At no stage is the Jet Stream at all strong through eastern Europe and into Russia and western Asia – so the cold block will not be broken up completely, which may be important much later on.  Looking at the extended charts (not shown as they are too far out) there are already signs of the Jet Stream starting to weaken again, particularly in the Atlantic where the main arm starts to dive well south of the UK again. This would be in line with possible HLB towards the second week in March and another sign to keep an eye on in a week or so.

Northern Hemisphere Current 2m Surface Temperatures and 850s:

                          GEFS ens mean 6z T+0                              GEFS ens mean 6z T+0

                gensnh-0-4-0.png              gensnh-0-0-0.png

Northern Hemisphere 2m Surface Temperatures and 850s for Sat Feb 25th – 0700:

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

                  gensnh-0-4-144.png               gensnh-0-0-144.png

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 much of the USA has resumed its unusually mild period following a brief cold snap in the north-eastern states with considerable snowfall. Most of the cold remains entrenched further north over much of Canada.   By next weekend, the colder air has seeped southwards over the western USA but the eastern states are particularly mild, if not warm. So, based on these charts, there will be little assistance from the thermal contrasts to fire up the Jet Stream any further, quite the reverse in fact. Note also, the build-up of  deep cold in the Arctic which I will return to later in this report. Another sign that we might yet see our coldest weather of the winter in early Spring!   

        London 2m Temperature Ensembles 0z February 19th to 6th March:

                                     ensemble-tt6-london.gif

COMMENTS (in respect of the Feb 19th chart - it updates automatically):

This very useful ensemble chart highlights the current (Sunday 0z) differences in the model output. It and similar charts for other locations are often posted on this thread but I like a little more analysis. Both the NCEP and ECM start off showing tomorrow’s warm day, then the cooling off around Friday into Saturday (more especially the ECM) followed by a return to milder conditions but nowhere near as mild as tomorrow will be.  Predicted temperatures are only slightly above average towards month end. Then the NCEP (op run goes at the mildest end well above the average indicated and only falling back on D15.  The ensemble means show an increasing number of much cold outcomes during the first week of March. This takes us right up to the suggested period for the start of the cold spell (if it happens). The next week will be a really fascinating one to watch for developments. Note that the ensemble charts shown by the likes of Knocker will not show these “possible” changes for a while. The 10-15 days means may start to towards the end of this week and more so by early next week.

Now on to my routine coverage.

Arctic Sea Ice News and Analysis:

The last full monthly report was published last week on February 7th. This is a fascinating but quite distressing read.  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 report and updates:

http://nsidc.org/arcticseaicenews/

This chart shows the current extent of the sea ice (as on February 18th) in relation to the 30 year means.

                  N_iqr_timeseries.png

   Source: National Snow and Ice Data Center (NSIDC)

COMMENT:  (relating to the chart above when it was showing February 18th data - it updates automatically each afternoon):

The “rate of recovery” during December was very close to a record but this was insufficient to avoid the overall extent still being at record lows. Since then, the position became steadily worse. There was a continued recovery (with several pauses) during January but sea ice growth had almost stalled and even receded slightly at a time when the Arctic is historically at its coldest. Fortunately, much stronger further growth has commenced during the last week. The overall ice extent remains well below the previous record low set during the  2012-13 Winter.  Now, we learn that sea ice extent in Antarctica  (late summer there) is also at record lows. Overall, the world’s sea ice is well below previous record lows.

This rapidly accelerating loss is extremely worrying and will have all sorts of adverse impacts on the world’s weather patterns. It may well go some way to explaining why we struggle to get any prolonged cold spells into our neck of the woods. This is an extremely complex subject which many experts are finding difficult to explain. Despite the background of global warming, let’s hope that the recent trend of greatly accelerated ice loss proves to be a temporary pattern.

Arctic Current Sea Surface Temperatures (SSTs):

                     NOAA SSTs  Feb 18th                          NOAA SST Anomalies Feb 18th

         color_newdisp_sst_north_pole_stereo_ophi                color_newdisp_anomaly_north_pole_stereo_

COMMENT:

Although the Arctic surface temperatures have fallen sharply during the last week (see later) and overall ice extent has been rising again, the two charts above go a long way to explain why there has been such a struggle for sea ice to grow in the Barents and Kara Seas on our side of the Arctic. The SSTs need to be below the -1.5c threshold (the purple colour). Sea water will start to freeze when it is below -2c but that is for normal salinity. There is slightly lower salt content in the Arctic (due to ice melt) and the threshold is nearer to -1.5c. There are some areas with SSTs well above freezing and the current anomalies are widely 4c to 6c above average and up to 8c above in places. These higher SSTs are a legacy of the 2015-16 winter when the Atlantic Jet Stream powered well into the Arctic for much of the first half of winter.  This shifted much warmer than average currents right up to the edge of the ice sheet. This anomaly is exceptional and comes on top of the already generally warming Arctic. It will be interesting to see how much ice growth can be achieved during the next few weeks with much colder surface conditions likely to persist. Unless the SSTs reduce substantially, the anomalies might be carried through the summer and into a third winter. I shall include a brief update on these in my future reports.

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:

    ao.sprd2.gif

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 19th data - it updates automatically each afternoon):

The Arctic Oscillation perfectly reflects the current GFS model output. It start off positive, briefly dips towards neutral later this week (the very brief colder snap), then goes strongly positive for about a week before all the ensemble members start to trend sharply lower later in week 2 with some going negative towards the end in early March – showing  signs of greater HLB then.

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:

   nao.sprd2.gif

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 19th data - it updates automatically each afternoon):

The NAO is slightly positive for most of the 2 week period but trending towards neutral later on with signs of it heading into negative territory after that. This broadly reflects fairly close to average pressure distributions in much of the north Atlantic with fairly low pressure to our north and west and the Azores HP to our south-west

MJO Ensemble charts:

Here are today's MJO ensemble charts for the big 4 (all updated on February 19th) + 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):

UKME_phase_23m_full.gifECMF_phase_MANOM_51m_full.gif NCPE_phase_21m_full.gifJMAN_phase_51m_full.gif realtimemjo.png  

 

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 19th data - they update automatically each afternoon): 

After broader agreement in the last 2 weeks we see some divergence again now. The big 4 all start off with the MJO in phase 1 at decent amplitude.  

Then the UKMO moves slowly through phase 1 and ends up next weekend near the phase 2 boundary maintaining good amplitude. 

The ECM takes a similar route over the same period, then progresses through phase 2 and on into phase 3 by the end of week 2 and at slightly reducing amplitude with some ensemble members moving towards the COD (the Circle of Death) - could this mark a later return to the positive phases 7, 8 and 1 during mid-March or might it become inactive?.

The GEFS takes a much more interesting route, holding for longer in phase 1 initially (perhaps in line with that very brief colder snap later this week) and then it heads erratically back towards the COD but very close to the phase 8 boundary (some members cross into phase 8 and stay there).  Then later in week 2 there is a renewed sign of life with a move back out of the COD towards the phase 7 and 8 boundary with some members moving into phase 7 at low amplitude. This is the longest forecast period of the big 4 and might be supportive of a move towards greater HLB by the second week of March. Early signs but one to watch very closely.

The JMA has simply fallen in love with phase 1 and hangs around there for the entire period at decent amplitude!

Kyle MacRitchie (with his adjusted model for ENSO and other tropical signals) is rather different. He starts off in phase 7, progressing through phase 8 during this week, then on though phase 1 next week reaching phase 2 around March 4th – all at good amplitude. Then all the members progress through phase 2, 3 and 4 by mid-March at slightly decreasing amplitude. Finally, they move into phase 5 bordering the COD  by March 21st.

Overall, a rather mixed picture but possibly some encouraging signs for later on.

As @Tamara and several other highly respected experts keep telling us, we cannot simply look at the MJO in isolation. It must be viewed in line with the other teleconnection signals which play an increasingly important role in helping us to understand and forecast forthcoming broader pattern changes. I do hope that even those who criticise these experts (extremely unfairly and without any factual basis whatsoever in my view – usually but not always through a lack of knowledge of the subject) realise that they have consistently done a far better job this winter than most of the longer term model output has managed. Tamara never got very excited about the December blocking (which turned out to be almost entirely MLB). She predicted that the January Arctic plunge would be a brief one. She then started to gain more interest herself  as the stratospheric warming events took place but she warned us that the main cold (if it comes) will be delayed until either late February or early March.  Sure enough, we had that 5 day recent easterly spell but that was too early and the promising Scandi HP sunk away southwards (much to my own disappointment, as I was championing the strength of the cold block, as well as for many others). So still the final hurdle to cross in terms of the possible (or even probable) upcoming cold spell but so far Tamara has been almost spot on. I have an increasing belief in the teleconnections science and will do my best to improve my understanding of it all. Who knows, I might even be able to make greater use of them in these reports in due course!

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 February 4th to February 18th but you can change these again on the site:

a) Animated Northern Hemisphere Snow Cover Changes (updated by NOAA February 18th):

https://www.ncdc.noaa.gov/snow-and-ice/snow-cover/nh/20170204-20170218

....and here is their current chart:

ims2017049.gif

b) Animated Europe and Asia Day Snow Cover (updated by NOAA February 18th):

https://www.ncdc.noaa.gov/snow-and-ice/snow-cover/ea/20170204-20170218

....and here is their current chart:

ims2017049_asiaeurope.gif

COMMENT: 

Little overall change during the last week. Part of central and much of eastern and south-eastern European is still snow covered (slightly receding in recent days). There continues to be well above average snow cover over northern, west and central Asia but a slight decline further south-east. Scandinavia remains 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 again during the last few days (the north-eastern states had quite a dumping a week ago).

The extensive snow cover over west Asia, Russia, eastern Europe and Scandinavia may well become very important if we are to see the right synoptics for a final attempt at another cold spell.

Finally, in the animated chart, you can clearly see the ice build-up towards Svalbard during the last few days. Yet another highly encouraging sign.

Current Arctic Regional Surface Temperatures:

 GFS mean– Northern Hemisphere Current Temperatures for February 19th 1900 (6z – T+12):

                                          gfsnh-9-12.png?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 previous readings from my last full report are shown in brackets alongside

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

Barents and Kara Seas:      -8c to -20c  (-4c to -20c).

Scandinavia:  south  +4c to 0c (-4c to -8c;  north  0c to -16c (0c to -8c).

Northern Siberia:     -28c to -40c  (-20c to -40c).

North West Russia:      -12c to -24c  (-4c to -8c)

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

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

Canadian Arctic:     -20c to -36c (little change).

Alaska:      -20c to -36c  (-12c to -40c).

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.

COMMENT:

Much of the Arctic, including the North Pole and Greenland as well as northern Siberia and parts of Russia have seen deepening cold. It looks like this trend will continue for at least the next week leading to the lowest values for the whole of this Winter. This would be very timely (for coldies) if we can manage the right synoptics in early March.

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 20th   -12c;           February 24th    -13 c;            February 28th   -10c.

North-West Svalbard – Ny-Alesund:  

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

February 20th    -14c;           February 24th     -19c;            February 28th   -12c.

Central South Svalbard – Sveagruva:   

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

February 20th     -12 c;           February 24th     -18c;            February 28th  -14c.    

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. 

COMMENT:

Temperatures had risen just above freezing for 10 days from late January into early February with the warmest period of the winter. Since then, temperatures have fallen back sharply and have been close to their 30 year means for the last 10 days and look set to continue near this level for the remainder of February and into March. This is excellent news on several counts. The recent recovery in the sea ice extent should continue at a far better rate. The SSTs should start to fall back and begin to reduce the exceptionally strong anomaly. Finally, for coldies, if we are to see some HLB with an Arctic air stream at some stage, the source of surface cold should be considerably lower than it has been at any time this winter (and for several past winters). This is the best news that I have been able to report on since I started monitoring these Arctic temperatures for my reports from January 2016. I did study Arctic temperatures for many years before I ever joined the NetWeather forum and I hope that the dreadful recent news on the declining sea ice will at least temporarily be ameliorated. 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:

This winter may be far from over. In early March it is highly likely that we shall see the deepest cold of the winter season  in the Arctic and also some more deep cold re-establishing itself in western Asia (where it has never really subsided since late October) and in north-west Russia. So, this is the deal for coldies – I shall lay on the cold to our north and east to tap into and our strat experts need to ensure that the final warming event at last creates the right synoptics to deliver it to the UK. A further deal to those that like a Spring warm up – allow us die hard coldies a decent cold and snowy spell first half to March, then we can all think of Spring. As I said last week, it’s all a mind set and we cannot control the weather – so just accept it. Proper Spring doesn’t start until March 21st and mother nature will catch up later on. I look forward to producing an even more encouraging report next Sunday.

NEXT UPDATE:

My next full weekly report should be on Sunday evening, February 26th.

 

Edited by Guest
Correcting typos and to ensure that all the links and charts work properly.
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@Steve Murr good to see you back. Before you went offline last week you said 

"a very important update that indicates a further SSW is forecast for the 21st of Feb with the deceleration date the 13th- so spanning 8 or so days we will go from the recovery peak of 30M/S to negative -5M/S ( approx )- this will probably be a wave 1 'final warming'

The CFS has been modelling this day after day for late Feb early march ( purple lines ) & the GFS is in full support

s

- once again, whilst there could be the usual lagged propergation of 10 days - the troposheric response around 16-18 Feb could replicate something very similar or better to what we have now- with a decent HLB ( poss 2) located nearer Greenland- whilst we possibly dont get a full vortex split the net result may well be the displaced vortex in to russia / Scandi -

Back closer to the hear & now - whilst the next 7-10 days feel like they have available energy to keep the blocking & -AO

So for me, we get over this cold spell & around the 16th-18th we are confronted by a quick fire SSW -- The modelling impacts on the AO are very profound with their negative manifestations-- some ensemble suites run it down to -6!!!"

Can I ask what is different this time around ? You seemed almost certain of a cold spell from 18th - 20th at the time.  The 10HPA and 30HPA forecasts seem to be as fickle as other NWP output? 

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52 minutes ago, Bring Back1962-63 said:

temp_eur2.png

Those temperatures in Turkey in insane from +15C to -21!

Note I would delete most of the quote if I knew how (edit it's really hard and takes a few tries because of double scrolling in compose window )

Quote

FINAL COMMENT:

This winter may be far from over. In early March it is highly likely that we shall see the deepest cold of the winter season  in the Arctic and also some more deep cold re-establishing itself in western Asia (where it has never really subsided since late October) and in north-west Russia. So, this is the deal for coldies – I shall lay on the cold to our north and east to tap into and our start experts need to ensure that the final warming event at last creates the right synoptics to deliver it to the UK. A further dea[/quote]l to those that like a Spring warm up – allow us die hard coldies a decent cold and snowy spell first half to March, then we can all think of Spring. As I said last week, it’s all a mind set and we cannot control the weather – so just accept it. Proper Spring doesn’t start until March 21st and mother nature will catch up later on. I look forward to producing an even more encouraging report next Sunday.

 

 

in 2013 there was a lot of cold in the ground and in the waters around us but not so now so I am afraid that any cold spell will just fall short with the strengthening sun and all

 

wow the northern hemisphere view is amazing the entire hemisphere north of 45 degrees latitude (and even very large areas between 30-45degrees latitude) is covered in snow, except for western europe

Edited by ArHu3
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Nothing in this evening's anomalies to suggest any significant movement away from the unsettled picture with temps slightly above average, with the usual caveat of some variation as systems negotiate the journey east in the westerly upper flow.

In the 5-10 period still a complex vortex arrangement with one lobe over NE Europe and the main lobe N.Canada/Greenland with associated troughs SW down N. America and SE into the mid Atlantic and a strong GOA ridge. Ergo a continuation of the energy flow exiting N. America on a pretty strong westerly jet driving systems east to traverse the UK. With the Azores HP still playing it's part this will still tend to favour a north south split which in turn won't rule out some transient incursions of Pm air as any systems pass through. But in general temps a little above average with again the SE remaining quite dry. As usual the detail to be sorted by the det, runs

ecm_eps_z500a_5d_nh_11.thumb.png.5dd48d3b1c617e45f5c90def2ee1a42e.pnggefs_z500a_5d_nh_41.thumb.png.a9d56068bca1524851de3753666f225b.png610day_03.thumb.gif.41b2c51de6f84f4e456fd728776996e0.gif

In the 10-15 period little significant change. The Canadian vortex consolidates and the GOA ridge retrogresses NW somewhat  A hint of some amplification in the Atlantic with the trough and maybe some positive anomalies in the Iceland area and some ridging over the UK but essentially much the same analysis and temps still above average.

gefs_z500a_5d_nh_61.thumb.png.baae4b6b17364c74aaad8ca084a4369e.png814day_03.thumb.gif.77ff346d38018a69d9e3eef09b5f579a.gif

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Plenty of upper ridging showing on the extended ens output. Just where it does establish unclear but the overall picture beginning to reflect where we were early Feb with the models looking mobile until the scandi height rise was picked up. Nothing too exciting for coldies as yet 

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Whilst it's relatively quiet on here it's interesting that from a behavioural aspect that the December of 2010 has certainly skewed perceptions that late November can be cold and early December are particularly snowy months but March 2013 has not skewed perceptions that March is particularly wintery.

Of course January and February are the historically most wintery for the UK.  I wonder if psychologically it's because November and December are the start of winter whilst March is the end (obviously not meteorological seasons before some one calls me out).

Anyway letting past events impact on future unconditional probabilities aka the gamblers fallacy is a repeating feature of the models thread come winter time and has been for many a year.

So it looks Atlantic driven for the next week, albeit a relatively benign Westerly pattern.  Unsettled would be the definition especially the further West you are.  Then it's wait and see wether the SSW can shake things up in terms of a last cold shot.  

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1 hour ago, knocker said:

Nothing in this evening's anomalies to suggest any significant movement away from the unsettled picture with temps slightly above average, with the usual caveat of some variation as systems negotiate the journey east in the westerly upper flow.

In the 5-10 period still a complex vortex arrangement with one lobe over NE Europe and the main lobe N.Canada/Greenland with associated troughs SW down N. America and SE into the mid Atlantic and a strong GOA ridge. Ergo a continuation of the energy flow exiting N. America on a pretty strong westerly jet driving systems east to traverse the UK. With the Azores HP still playing it's part this will still tend to favour a north south split which in turn won't rule out some transient incursions of Pm air as any systems pass through. But in general temps a little above average with again the SE remaining quite dry. As usual the detail to be sorted by the det, runs

ecm_eps_z500a_5d_nh_11.thumb.png.5dd48d3b1c617e45f5c90def2ee1a42e.pnggefs_z500a_5d_nh_41.thumb.png.a9d56068bca1524851de3753666f225b.png610day_03.thumb.gif.41b2c51de6f84f4e456fd728776996e0.gif

In the 10-15 period little significant change. The Canadian vortex consolidates and the GOA ridge retrogresses NW somewhat  A hint of some amplification in the Atlantic with the trough and maybe some positive anomalies in the Iceland area and some ridging over the UK but essentially much the same analysis and temps still above average.

gefs_z500a_5d_nh_61.thumb.png.baae4b6b17364c74aaad8ca084a4369e.png814day_03.thumb.gif.77ff346d38018a69d9e3eef09b5f579a.gif

An interesting D8-D14 NOAA chart there - could well lead to another bout of continental influence at the surface the further S and E one goes - but that could mean anything from a warmer southerly to some sneaky cooler shots from an easterly direction - all depending on what type of air is out there at this time of year. More likely the former, looking out for the latter.

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The 18z GEFS are an absolute snorter.

gensnh-1-1-360_nry3.pnggensnh-2-1-348_jzz6.pnggensnh-3-1-384_ppo2.png

gensnh-4-1-348_vin2.pnggensnh-6-1-336_jyi1.png

 

The rest either rip the PV to tatters, bring surface cold, have brutal cold just south or east of us or would bring cold down the line (odd 1 excepted)

NOT 1 is out and out zonal.

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4 hours ago, ArHu3 said:

Those temperatures in Turkey in insane from +15C to -21!

Note I would delete most of the quote if I knew how (edit it's really hard and takes a few tries because of double scrolling in compose window )

in 2013 there was a lot of cold in the ground and in the waters around us but not so now so I am afraid that any cold spell will just fall short with the strengthening sun and all

 

 

 

wow the northern hemisphere view is amazing the entire hemisphere north of 45 degrees latitude (and even very large areas between 30-45degrees latitude) is covered in snow, except for western europe

Ahhhh yes Turkey, fast becoming the new Winter wonderland of the 21st century, who needs Lapland anymore, no doubt Santa will be moving down there soon.:rofl:

gfs-9-6.png

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Looked over 18z FI for a laugh and saw this. Lucky its so far out it is for mere entertainment value, but would be another taste of winter for Europe, and a fairly potent one. Lucky it is in the furthest reaches of FI

gfs-0-384 (10).png

gfs-1-384 (1).png

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5 hours ago, Trom said:

Whilst it's relatively quiet on here it's interesting that from a behavioural aspect that the December of 2010 has certainly skewed perceptions that late November can be cold and early December are particularly snowy months but March 2013 has not skewed perceptions that March is particularly wintery.

Of course January and February are the historically most wintery for the UK.  I wonder if psychologically it's because November and December are the start of winter whilst March is the end (obviously not meteorological seasons before some one calls me out).

Anyway letting past events impact on future unconditional probabilities aka the gamblers fallacy is a repeating feature of the models thread come winter time and has been for many a year.

So it looks Atlantic driven for the next week, albeit a relatively benign Westerly pattern.  Unsettled would be the definition especially the further West you are.  Then it's wait and see wether the SSW can shake things up in terms of a last cold shot.  

On that note a pinned post on logical fallacies would be useful for the model section of the forum in winter. We are all guilty of it from time to time, but unscientific, illogical and even magical thinking is too prevalent here at times.

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