[Snow and Ice Northern Hemisphere - Winter 23 /24]

****** SO ON TO THE BRILLIANT NEWS I PREDICTED YESTERDAY   *****

The JAXA sea ice extent has smashed through the average for 2000' barrier. 

This morning (and for me it was key) the ASIF figures told the story...

     

Not only that, but it went past the 2004 numbers also. 

That now only leaves 2000 to 2003 to challenge, as we hit 21st lowest from the last 20 years!!!

A day I (having listened to some) thought would never occur in my lifetime.

This mornings/d NATICE show decreases in the East but compensated by increases in the west with Barents and Baltic racing ahead again.

       

 

Today worth celebrating.          

MIA

[Snow and Ice Northern Hemisphere - Winter 23 /24]

20 minutes ago, nobble said:

Hi MIA

 

a question , is the northern hemisphere no gaining more ice as a result of a good refreeze , and a viscous circle of more ice making conditions colder and more ice forming ? A perfect storm if you will ? 
 

as you say in a “warming world “ some would say this is not possible , 

 

but clearly it’s happening

Cannot answer you directly as I promised the thread would not mention CC !

What you say is correct, Nobbie - but why is more ice being produced in the first place?

Is it the result of 3 years of La Nina??? 

if so it will change again very soon.

Is it the result of the Hunga Tonga Volcano ?      People on the ASIF deny this, though it could have been is my opinion.

It might be associated with the salinity of the oceans, though they do not appear to have changed.

So the only thing we know for sure is that the  temperature of the oceans has lowered.

but all the CC measurements say this is not so..

I DO NOT KNOW is the answer.

 I am expecting some more incredible news tomorrow on the ice front.

MIA

 

 

 

 

[Snow and Ice Northern Hemisphere - Winter 23 /24]

Friday was  my last update for Scandinavia , but the total ice situation in the N H is going BONKERS right now....

First to the snow reports where the situation is starting to improve, particularly in Europe, and I expect this to advance rapidly this week as Scandinavia moves into Europe for a while.  Expect the US to follow suite soon.

       

Then to the sea ice -

Well after 6 days of gains in total extent, Masie has again increased by +160K KM2 today after previous gains of (+2K (a week ago), +53K, +66K , +100K, +78K. +89K, +160K) towards a total of 13,887K Km2.

  

To put this in perspective 14M Km2  has not been reached until February for about  the last 10 years now (apart from 1 year), and this is all with an apparent increasing temperature worldwide trend. The normal average increase for this time of year is a +40K increase!!!!! There is little doubt now that the reason is the outer sea areas that are freezing over very rapidly this year, despite we are told these rapidly increasing temperatures !!!

I am totally at a loss to give any explanation, without upsetting a lot of people.

Any ways   - the outer sea ice charts for today tell the story -

      

           

 

You can see the gist of it.

It is to many unexpected,  and it is quite amazing, though it  has been a possibility following the ice increases being well above trend this freeze up  year. Jaxa on ASIF is rapidly chasing down the average for the 2000's, after overtaking all years since  2004.

Meanwhile currently in the UK, we are awaiting the outcome of a complex weather situation,  .... Can we join in the fun??

MIA

 

[Model Output Discussion - Into 2024]

4 minutes ago, seabreeze86 said:

Small ridge from the pacific helping instead of hindering this time perhaps?

yep.. small ridges will be useful, its the big round blobby highs (on that side) which transfer the cold back eastwards we do not want. 

MIA

[Model discussion highlights]

My thoughts on the current situation after reading back through the last 4 to 6 pages.  (for what its worth!!)

I see Blue has beaten me too it    but anyways....

4 days ago now we saw the start up of the second warming of the year, after the telecommunications had been proved pretty accurate.

No charts yet today of the (SSW's/ warming) status yet today           BUT

We do know that 3 days ago all the charts were lined up (GFS climbed into bed last) and that they all aligned along with all the telecommunications you could want.

Then ECM was first to wander. By  coincidence  It appears it has the best (most reactive at any rate) of all the suites to any 'warming' impact in the strat. I might use the term SSW, but a warming of the strat (whilst it is in a weakened state will have very similar effects as those produced by a full on SSW), so I will use interchangeably from now on in this note.

So ECMWF picked up a change first, and started to show the development of a huge PACIFIC high on the Russian side first.  At day 10 I think.

This straight away pushed more of the vortex back in towards Canada, and started to leave Greenland less prone to our  retrogressing high as suggested by the telecommunications tendencies.

The next day the ECMWF  produced a different position for the Pacific high, but with similar results for the Atlantic. Also some of the other models changed slightly;  by now the 'SSW' had become stronger, and some of the other models started to 'wobble', but were not yet being picked up as strong enough to deflect the strong telecommunications  effect.

So on a further day (yesterday , I think) and the ECM produces charts showing a huge Pacific high deflecting the PV back over towards its natural home, (unfortunately Greenland it seems) and try as they might,  it overrides every telecommunications signal. By now more of the  other models started the 'wobbling' process, as the initial effects  of the SSW started to move down into the troposphere.  

Onto the here and now - still more of the models move over to the ECMWF way of looking at things, and by now the ECMWF thinks that things have moved so far that they are irreversible and that the Northern hemisphere will revert back to its default status, with the loss of the high level blocking. 

I am not discounting the fact that the ECM may be overreacting to the signals, so all may not yet be lost., 

 

However no new telecommunications signals had appeared during the above events. The only thing that changed was the early appearance of the SSW  (strat warming). It is my belief that no new 'teles' appeared and that it  is this that has changed the outlook.

If you remember, before this event ( a week ago)  when the latest warming was picked up it was thought that it would make its presence felt by the end of next week (not this), and this was hoped that it would lengthen the period of cold by the then draining cold outlook. Maybe we underestimated its abilities to rapidly impact the troposphere.

Well once again it has not worked in favour of our little bit of the world, whilst other areas (North America again!!) are plunged into cold.  Does luck come into it? I do not know but it sure feels like it.

The thing is that there must have been some other ' drivers' at work causing the rapid onset of the new SSW.

Sorry no charts for the above since  I have to go out now, and I  felt it would have been too long a post. I hope you agree that it is a reasonable summary of the events -. even if you do not agree with the conclusions.

Lastly - the big question is. Is the ECMWF correct?    We have not been able to witness this sort of balancing act between the strat and trop before at this level of detail..

I find it fascinating.

MIA

Original post: https://community.netweather.tv/topic/99706-model-output-discussion-into-2024/?do=findComment&comment=4999202

[Model Output Discussion - Into 2024]

My thoughts on the current situation after reading back through the last 4 to 6 pages.  (for what its worth!!)

I see Blue has beaten me too it    but anyways....

4 days ago now we saw the start up of the second warming of the year, after the telecommunications had been proved pretty accurate.

No charts yet today of the (SSW's/ warming) status yet today           BUT

We do know that 3 days ago all the charts were lined up (GFS climbed into bed last) and that they all aligned along with all the telecommunications you could want.

Then ECM was first to wander. By  coincidence  It appears it has the best (most reactive at any rate) of all the suites to any 'warming' impact in the strat. I might use the term SSW, but a warming of the strat (whilst it is in a weakened state will have very similar effects as those produced by a full on SSW), so I will use interchangeably from now on in this note.

So ECMWF picked up a change first, and started to show the development of a huge PACIFIC high on the Russian side first.  At day 10 I think.

This straight away pushed more of the vortex back in towards Canada, and started to leave Greenland less prone to our  retrogressing high as suggested by the telecommunications tendencies.

The next day the ECMWF  produced a different position for the Pacific high, but with similar results for the Atlantic. Also some of the other models changed slightly;  by now the 'SSW' had become stronger, and some of the other models started to 'wobble', but were not yet being picked up as strong enough to deflect the strong telecommunications  effect.

So on a further day (yesterday , I think) and the ECM produces charts showing a huge Pacific high deflecting the PV back over towards its natural home, (unfortunately Greenland it seems) and try as they might,  it overrides every telecommunications signal. By now more of the  other models started the 'wobbling' process, as the initial effects  of the SSW started to move down into the troposphere.  

Onto the here and now - still more of the models move over to the ECMWF way of looking at things, and by now the ECMWF thinks that things have moved so far that they are irreversible and that the Northern hemisphere will revert back to its default status, with the loss of the high level blocking. 

I am not discounting the fact that the ECM may be overreacting to the signals, so all may not yet be lost., 

 

However no new telecommunications signals had appeared during the above events. The only thing that changed was the early appearance of the SSW  (strat warming). It is my belief that no new 'teles' appeared and that it  is this that has changed the outlook.

If you remember, before this event ( a week ago)  when the latest warming was picked up it was thought that it would make its presence felt by the end of next week (not this), and this was hoped that it would lengthen the period of cold by the then draining cold outlook. Maybe we underestimated its abilities to rapidly impact the troposphere.

Well once again it has not worked in favour of our little bit of the world, whilst other areas (North America again!!) are plunged into cold.  Does luck come into it? I do not know but it sure feels like it.

The thing is that there must have been some other ' drivers' at work causing the rapid onset of the new SSW.

Sorry no charts for the above since  I have to go out now, and I  felt it would have been too long a post. I hope you agree that it is a reasonable summary of the events -. even if you do not agree with the conclusions.

Lastly - the big question is. Is the ECMWF correct?    We have not been able to witness this sort of balancing act between the strat and trop before at this level of detail..

I find it fascinating.

MIA

[Model discussion highlights]

On 04/01/2024 at 12:39, Midlands Ice Age said:

Whilst quiet in here(?), I did some work back in 2018 on most of the severe cold spells since 1860 showing where/what  they came from and what was the temps (850's) in the region the outbreaks occurred (generally Iceland for northern based and 'Moscow' for eastern based) ln and what was the CET as a result.

I did this by examination of the reanalysis charts after consulting people on the web (and in here) about what cold outbreaks to include.

I tried to publish the data, but couldn't do it properly, I might try again soon now if I can find the data. 

Anyway I still have the hardcopy and I am checking the data, and I give the relevant data in summary below.......

 I organised it in month order -  

During November, until Nov 2010 (Greenland based) there were very few other cold spells (3  - in 1978, 1904 and 1890.  (temps of 850 in 2010 was -14C, but fell to -20C at source,     CET -1.9C)

In December - 25 occurrences  mostly from straight northerlies. Greenland 'forced'   - a few of them, but mostly easterly based. when -28C  (in Dec 1892) was the coldest source and the CET was --3.12C).

Most Greenies started as a UK high and the coldest 850''s was in 1927 and 1892 when -24C was the 850.  These produced CET's of 

--2.6 and -3.37C respectively.

 

So onto January - when I recorded 31 cold spells.

Most based upon Siberian highs after Northerlies and a UK high..

Greenland based were in 1987 (-3.0C) , 1982(-4.03C),  1963(-3.56C), nearly all the early 1940's,    coldest (-3.49 in 1940),   1894(_4,4C) ,  1881 (-4.38C) .

These were produced by the lowest Greeny based 850's of between -20C and -28C) from the air sourced above/over Iceland. 

850's over the UK were (associated with the colder outbreaks) between -14C and -18C, otherwise -10C to -14C.

Gives you an idea of what may be possible if things go according to way they are being shown today.

I also have data for February, March and April - but I will leave that for later!!!, 

This is not to say something  will happen - as there are many 'risks' to overcome first.

I also have some research into that looking at how many cold spells followed blizzards, but I will leave that to another post.

Hope the mods are happy me posting this on the model thread, but many people would like to know what is the 'worst/best ' we can expect.

MIA

 

After the good response to the above post, I decided that (as opposed to the best values above), I would produce an average expectation as to what the CET might be from both the UK 850's and the 'Source' 850's. IF IT WAS POSSIBLE...

 Before I present any results I think people need to understand the restrictions -

1) The cold weather investigated had to be at least a 5 day spell of cold temperatures from the CET record and not to average above 0C.

2) as stated above data for the 850's was taken from the Meteorciel Renalysis charts either north of Iceland (for Greenies or a straight northerly) and Moscow for either Scandies or Russian  cold.

3) To match up roughly with the CET, I used 850's from 20 miles within the UK coastline, hence eliminating extreme Scandy highs in the North Sea, etc.

4) The CET  was the average of the 5 days or more of the event, and  if extended or repeated in the same month/year would show as separate events. Thus 1962 - 63 has 3 events (one for Dec, one for Jan and one for February).

 

It looked a reasonable simple task with 4 events for Nov,  31 for December, 33 for January, 30 events for February and 4 for March, in the database.

 

I discarded the November and March data as they were few in number  and had occurred mainly in the last 50 years . Why has this started to happen?

Also it was clear that the heat of the sun was a factor.

 

So the total number of events in my database was 94 - a reasonable sized data repository.

So fairly obvious (I thought) was to plot the 850 against CET  -          but this produced spaghetti.

So I repeated by month and it gave some results which showed that cold in December was better from the 850;s , than January, however  they were both  in  the main much colder CET wise  than February.   HOWEVER,  there were 2 events in early February which were exceptional (vis 1/2/56 CET 4.08C, and 5/2/1895 CET 4.81C) which were brutal. They both had severe Arctic  blizzard outbreaks before clear skies moved in from the East allowed the night time temps to plummet for several days.. 

 

So turned to compare the 'Source 850's' against the CET.

Immediately it was obvious that a better linear pattern was present for 85 of the events, with some sticking out above  (the Feb ones above), and some below - which all turned out to near UK based highs -  where the cold temps had built up 'in situ'  with high/medium  850's, which hadn't changed much.

However,  for the vast majority of cases the linear fit was -4.5C for -30C for Source 850's -  at the top of the range;   to +0C  CET for an -4.C Source 850 at the lower end of the range.  The above straight line graph also includes values  of about +/- 0.75C CET  on either side for each 850 of Source cold for the distribution.

To help a bit I have produced the below table of the straight line graph.

Source 850        -30C       -25C       -20C         -15C         -10C            -5C              0C

CET                    -4.6C      -3.8C      -2.9C         -2.0C        -1.2C         -0.4C            +0.5C

Please remember that values can be increased or decreased by about 0.75C from these valued depending upon factors like cloud and wind, over the UK, which can change the average position.

The most extreme position I have heard of was in the 17th century when a 50 mph blizzard directly from Siberia kept the temps around -10C for 3 days solid in SE England, whilst the rest of us 'boiled'  in -6C CET's..  Must have been some watch!!! Pity we didn't have N.W.  in those days.

The above are only intended to be a guide,     possibly for the less experienced.

!I hope you will find these useful many times in the future, and lets hope for top quality weather watching  this year.

MIA                              

 

Original post: https://community.netweather.tv/topic/99706-model-output-discussion-into-2024/?do=findComment&comment=4998510

[Model Output Discussion - Into 2024]

On 04/01/2024 at 12:39, Midlands Ice Age said:

Whilst quiet in here(?), I did some work back in 2018 on most of the severe cold spells since 1860 showing where/what  they came from and what was the temps (850's) in the region the outbreaks occurred (generally Iceland for northern based and 'Moscow' for eastern based) ln and what was the CET as a result.

I did this by examination of the reanalysis charts after consulting people on the web (and in here) about what cold outbreaks to include.

I tried to publish the data, but couldn't do it properly, I might try again soon now if I can find the data. 

Anyway I still have the hardcopy and I am checking the data, and I give the relevant data in summary below.......

 I organised it in month order -  

During November, until Nov 2010 (Greenland based) there were very few other cold spells (3  - in 1978, 1904 and 1890.  (temps of 850 in 2010 was -14C, but fell to -20C at source,     CET -1.9C)

In December - 25 occurrences  mostly from straight northerlies. Greenland 'forced'   - a few of them, but mostly easterly based. when -28C  (in Dec 1892) was the coldest source and the CET was --3.12C).

Most Greenies started as a UK high and the coldest 850''s was in 1927 and 1892 when -24C was the 850.  These produced CET's of 

--2.6 and -3.37C respectively.

 

So onto January - when I recorded 31 cold spells.

Most based upon Siberian highs after Northerlies and a UK high..

Greenland based were in 1987 (-3.0C) , 1982(-4.03C),  1963(-3.56C), nearly all the early 1940's,    coldest (-3.49 in 1940),   1894(_4,4C) ,  1881 (-4.38C) .

These were produced by the lowest Greeny based 850's of between -20C and -28C) from the air sourced above/over Iceland. 

850's over the UK were (associated with the colder outbreaks) between -14C and -18C, otherwise -10C to -14C.

Gives you an idea of what may be possible if things go according to way they are being shown today.

I also have data for February, March and April - but I will leave that for later!!!, 

This is not to say something  will happen - as there are many 'risks' to overcome first.

I also have some research into that looking at how many cold spells followed blizzards, but I will leave that to another post.

Hope the mods are happy me posting this on the model thread, but many people would like to know what is the 'worst/best ' we can expect.

MIA

 

After the good response to the above post, I decided that (as opposed to the best values above), I would produce an average expectation as to what the CET might be from both the UK 850's and the 'Source' 850's. IF IT WAS POSSIBLE...

 Before I present any results I think people need to understand the restrictions -

1) The cold weather investigated had to be at least a 5 day spell of cold temperatures from the CET record and not to average above 0C.

2) as stated above data for the 850's was taken from the Meteorciel Renalysis charts either north of Iceland (for Greenies or a straight northerly) and Moscow for either Scandies or Russian  cold.

3) To match up roughly with the CET, I used 850's from 20 miles within the UK coastline, hence eliminating extreme Scandy highs in the North Sea, etc.

4) The CET  was the average of the 5 days or more of the event, and  if extended or repeated in the same month/year would show as separate events. Thus 1962 - 63 has 3 events (one for Dec, one for Jan and one for February).

 

It looked a reasonable simple task with 4 events for Nov,  31 for December, 33 for January, 30 events for February and 4 for March, in the database.

 

I discarded the November and March data as they were few in number  and had occurred mainly in the last 50 years . Why has this started to happen?

Also it was clear that the heat of the sun was a factor.

 

So the total number of events in my database was 94 - a reasonable sized data repository.

So fairly obvious (I thought) was to plot the 850 against CET  -          but this produced spaghetti.

So I repeated by month and it gave some results which showed that cold in December was better from the 850;s , than January, however  they were both  in  the main much colder CET wise  than February.   HOWEVER,  there were 2 events in early February which were exceptional (vis 1/2/56 CET 4.08C, and 5/2/1895 CET 4.81C) which were brutal. They both had severe Arctic  blizzard outbreaks before clear skies moved in from the East allowed the night time temps to plummet for several days.. 

 

So turned to compare the 'Source 850's' against the CET.

Immediately it was obvious that a better linear pattern was present for 85 of the events, with some sticking out above  (the Feb ones above), and some below - which all turned out to near UK based highs -  where the cold temps had built up 'in situ'  with high/medium  850's, which hadn't changed much.

However,  for the vast majority of cases the linear fit was -4.5C for -30C for Source 850's -  at the top of the range;   to +0C  CET for an -4.C Source 850 at the lower end of the range.  The above straight line graph also includes values  of about +/- 0.75C CET  on either side for each 850 of Source cold for the distribution.

To help a bit I have produced the below table of the straight line graph.

Source 850        -30C       -25C       -20C         -15C         -10C            -5C              0C

CET                    -4.6C      -3.8C      -2.9C         -2.0C        -1.2C         -0.4C            +0.5C

Please remember that values can be increased or decreased by about 0.75C from these valued depending upon factors like cloud and wind, over the UK, which can change the average position.

The most extreme position I have heard of was in the 17th century when a 50 mph blizzard directly from Siberia kept the temps around -10C for 3 days solid in SE England, whilst the rest of us 'boiled'  in -6C CET's..  Must have been some watch!!! Pity we didn't have N.W.  in those days.

The above are only intended to be a guide,     possibly for the less experienced.

!I hope you will find these useful many times in the future, and lets hope for top quality weather watching  this year.

MIA                              

 

[Model Output Discussion - Into 2024]

I am wondering if the ECM is picking up the first signs of trop changes due to the current ongoing rapid warming in the strat.

I know that it is only 13 days  from when it first started (3 days ago), but the strat is now already in a severely weakened state and maybe it is able to move along more quickly.

I would not expect the GFS to pick it up yet (from my research) , and the MO does  not go out far enough.

Is the EC picking up the westerly wind down burst already?

Perhaps its all balls in the air time?

MIA

 

[Snow and Ice Northern Hemisphere - Winter 23 /24]

Couldn't find it, but this is a sample of places not as badly affected -

In pictures: Nordic states gripped by winter freeze - BBC News 

https://www.bbc.co.uk/news/in-pictures-67871751  

 

 

[Snow and Ice Northern Hemisphere - Winter 23 /24]

14 hours ago, cheese said:

It's a bit dark but you can see the Baltic Sea in Stockholm frozen over here (specifically the bay called Saltsjön).

 

Yep

Scandinavia really going into the freezer now, Finland and Sweden have been there for a few days now.

I have just been watching a video issued by Southern Norway authorities issued on the Mon - Wed snowstorm this week.

It was mainly coastal based apparently, whereas in  the mountains behind the coastal strip the roads were still open.

Towns on the coast were paralysed by up to 1 metre of snow and drifts the size of houses, 

I understand that Denmark was similar.

     The snow is now showing up on the north of the European continent I think in advance of a more general increase this week.

Meanwhile the Baltic ice continues to grow 

      as does the Northern hemisphere sea ice extent.

Jaxa is now showing us at the highest level in the last 20 years and is now approaching the levels seen in the early 2000;s. 20/20 full maximum house (thanks ASIF)

       

However, before comment, we may be just at a sweet spot for ice this year, particularly as we are forecast a major outflow of the cold air into both Europe and North America this next week, whilst the Pacific is already cold and in full ice mode . The question is will any 'warmer' air move in to replace the colder air in the Arctic   -  I suspect it would  make little difference to the sea ice extent, but may impact the volumes and ice concentrations. if it does. 

We do not have the latest DMI temp for the Arctic Basin yet (EOY), but up until the end of last year we were moving into a colder Arctic than we have seen recently. This would tie in with the extra ice currently being seen.

  

All for now...  I'll show the video of Norway blizzards  if I can find it.

MIA

 

[Model discussion highlights]

4 hours ago, claret047 said:

Good Morning everyone from a great fan of snow. Hoping what I am posting is not off topic but I would appreciate being permitted to ask a question of the more knowledgeable on this thread. 

Do all models use the same resources to collect their data in order to do their modelling? The reason I ask is that I believe the GFS is an American model (please correct me if I am wrong) and wonder if they have more information as far as modelling the area around Greenland. If so perhaps they can predict that area better than ECM or UKMO. Hopefully that is not the case as we all want the evolutions of the other two models to be correct. 

A very good question and one that I have thought about myself after watching one of the American forecasters (on X) over there give his outlook  for the USA (using all the available models), for the next 7 days....

For interest only,  they are fore-seeing freezing conditions spreading in during the weekend and then across to all but the extreme east and north east by next weekend, with the possibilities of record lows.. So a massive change for them.

However interestingly, for all but the short term prognosis (where he used the GFS mainly, but for some precipitation charts he used  a 'blend' of the others) ,  he used the GEM and ECMWF models for most of his outlook after 3 days. Sometimes he would state that he had used a blended forecast (GFS 40, ECM 40, GEM 20), etc..  but mainly ECMWF. 

I have noticed this before when watching US forecasts that they frequently state that they are using ECM and GEM rather than GFS,  almost as if they do not think the GFS is accurate, in their corner of the globe..

As Paul  says above they use more or less the same starting data, but I am beginning to suspect that the GFS  is quite weak on any stratospheric medium outlook influences, when it gets to the 10-12 days ahead outlook,  They seem to be able to pick up at a way out timescale, but then seem to wander away from it again for a while,  until it comes back into more the reliable.....    

This 'feeling' is  shown by the way in which the GFS suddenly 'veered away' from the rest  at the start of this chase over a week ago now.  And we know from the ECMWF blogg (on SEVERE weather EU),  that  the GFS were not seeing any strat changes, when it was being shown that all other models had picked them up back in late December..

HOWEVER , could it have been that actually the rest left the GFS behind,(?? -likely in my opinion),   as they factored in the warming of the Stratosphere, and moved it into its tropospheric effects - even though it did not actually cause an SSW, it has certainly weakened the jet flows around the world. Perhaps GFS at the shorter range only use the tropospheric data and  then will slowly come back onside again.

It would also explain why the GFS was so good on the last cold spell - where it was totally tropospherically based, - and it seemed to wind it down to zero better than the other models..

Back to here and now again...We now see that ECMWF are seeing another rapid warming occuring at the  same time as GFS apparently veers away from the rest again.

\Will it be correct this time or will it come back into the fold as the effects of the latest warming actually become apparent at lower levels (possibly in 10 days time).

Last week the GFS  took quite a while to gradually come back 'in fold', (3days?) - maybe as they started picking up on the actual tropospheric influence of the partial and minor SSW which occured at the same time as the charts merged together again. 

Do they use different programs for their longer range compared to their more immediate  forecasts? Certainly we have seen sometimes how their 13- 15 days forecasts suddenly go totally haywire. (as shown up by the pub run?)

This would explain the type of behaviour of the models that many of the more experienced of the guys have observed on here....

That is the GFS picking up way in advance a pattern change, only to drop it ., and then come back to it again after the other models (about 10 days) have picked up on it and then the GFS  returns to the fold very slowly at days 10 to 5,

I am sorry if this post is difficult to follow, but it is quite difficult to describe the fluctuations of the GFS. - Sorry mods 

Note you GFS fans, I am  not decrying the GFS,,, but it is these highly visible times that it seems it sometimes behaves strangely - but in a consistent manner. 

We will see  whether the above is 'tosh' or indeed correct.

MIA

Original post: https://community.netweather.tv/topic/99706-model-output-discussion-into-2024/?do=findComment&comment=4996546

[Model Output Discussion - Into 2024]

4 hours ago, claret047 said:

Good Morning everyone from a great fan of snow. Hoping what I am posting is not off topic but I would appreciate being permitted to ask a question of the more knowledgeable on this thread. 

Do all models use the same resources to collect their data in order to do their modelling? The reason I ask is that I believe the GFS is an American model (please correct me if I am wrong) and wonder if they have more information as far as modelling the area around Greenland. If so perhaps they can predict that area better than ECM or UKMO. Hopefully that is not the case as we all want the evolutions of the other two models to be correct. 

A very good question and one that I have thought about myself after watching one of the American forecasters (on X) over there give his outlook  for the USA (using all the available models), for the next 7 days....

For interest only,  they are fore-seeing freezing conditions spreading in during the weekend and then across to all but the extreme east and north east by next weekend, with the possibilities of record lows.. So a massive change for them.

However interestingly, for all but the short term prognosis (where he used the GFS mainly, but for some precipitation charts he used  a 'blend' of the others) ,  he used the GEM and ECMWF models for most of his outlook after 3 days. Sometimes he would state that he had used a blended forecast (GFS 40, ECM 40, GEM 20), etc..  but mainly ECMWF. 

I have noticed this before when watching US forecasts that they frequently state that they are using ECM and GEM rather than GFS,  almost as if they do not think the GFS is accurate, in their corner of the globe..

As Paul  says above they use more or less the same starting data, but I am beginning to suspect that the GFS  is quite weak on any stratospheric medium outlook influences, when it gets to the 10-12 days ahead outlook,  They seem to be able to pick up at a way out timescale, but then seem to wander away from it again for a while,  until it comes back into more the reliable.....    

This 'feeling' is  shown by the way in which the GFS suddenly 'veered away' from the rest  at the start of this chase over a week ago now.  And we know from the ECMWF blogg (on SEVERE weather EU),  that  the GFS were not seeing any strat changes, when it was being shown that all other models had picked them up back in late December..

HOWEVER , could it have been that actually the rest left the GFS behind,(?? -likely in my opinion),   as they factored in the warming of the Stratosphere, and moved it into its tropospheric effects - even though it did not actually cause an SSW, it has certainly weakened the jet flows around the world. Perhaps GFS at the shorter range only use the tropospheric data and  then will slowly come back onside again.

It would also explain why the GFS was so good on the last cold spell - where it was totally tropospherically based, - and it seemed to wind it down to zero better than the other models..

Back to here and now again...We now see that ECMWF are seeing another rapid warming occuring at the  same time as GFS apparently veers away from the rest again.

\Will it be correct this time or will it come back into the fold as the effects of the latest warming actually become apparent at lower levels (possibly in 10 days time).

Last week the GFS  took quite a while to gradually come back 'in fold', (3days?) - maybe as they started picking up on the actual tropospheric influence of the partial and minor SSW which occured at the same time as the charts merged together again. 

Do they use different programs for their longer range compared to their more immediate  forecasts? Certainly we have seen sometimes how their 13- 15 days forecasts suddenly go totally haywire. (as shown up by the pub run?)

This would explain the type of behaviour of the models that many of the more experienced of the guys have observed on here....

That is the GFS picking up way in advance a pattern change, only to drop it ., and then come back to it again after the other models (about 10 days) have picked up on it and then the GFS  returns to the fold very slowly at days 10 to 5,

I am sorry if this post is difficult to follow, but it is quite difficult to describe the fluctuations of the GFS. - Sorry mods 

Note you GFS fans, I am  not decrying the GFS,,, but it is these highly visible times that it seems it sometimes behaves strangely - but in a consistent manner. 

We will see  whether the above is 'tosh' or indeed correct.

MIA

[Snow and Ice Northern Hemisphere - Winter 23 /24]

1 hour ago, Aleman said:

The isotherms are absolute. The figures in bubbles are a historical mean, I think. Remember that the Gulf of Bothnia is almost fresh water. Salinity only approaches typical deep sea levels as you leave the Danish Straights

 

 

Thanks Aleman - that makes a lot more sense of it all.

MIA  

[Model discussion highlights]

Whilst quiet in here(?), I did some work back in 2018 on most of the severe cold spells since 1860 showing where/what  they came from and what was the temps (850's) in the region the outbreaks occurred (generally Iceland for northern based and 'Moscow' for eastern based) ln and what was the CET as a result.

I did this by examination of the reanalysis charts after consulting people on the web (and in here) about what cold outbreaks to include.

I tried to publish the data, but couldn't do it properly, I might try again soon now if I can find the data. 

Anyway I still have the hardcopy and I am checking the data, and I give the relevant data in summary below.......

 I organised it in month order -  

During November, until Nov 2010 (Greenland based) there were very few other cold spells (3  - in 1978, 1904 and 1890.  (temps of 850 in 2010 was -14C, but fell to -20C at source,     CET -1.9C)

In December - 25 occurrences  mostly from straight northerlies. Greenland 'forced'   a few of them, mainly easterly based. when -28C  (in Dec 1892) was the coldest source and the CET was --3.12C).

Most Greenies started as a UK high and the coldest 850''s was in 1927 and 1892 when -24C was the 850.  These produced CET's of 

--2.6 and -3.37C respectively.

 

So onto January - when I recorded 31 cold spells.

Most based upon Siberian highs after Northerlies and a UK high..

Greenland based were in 1987 (-3.0C) , 1982(-4.03C),  1963(-3.56C), nearly all the early 1940's coldest (-3.49 in 1940),   1894(_4,4C) ,  1881 (-4.38C) .

These were produced by the lowest Greeny based 850's of between -20C and -28C) from the air sourced above/over Iceland. 

Gives you an idea of what may be possible if things go according to way they are being shown today.

I also have data for February, March and April - but I will leave that for later!!!, 

This is not to say something  will happen - as there are many 'risks' to overcome first.

I also have some research into that looking at how many cold spells followed blizzards, but I will leave that to another post.

Hope the mods are happy me posting this on the model thread, but many people would like to know what is the 'worst/best ' we can expect.

MIA

 

Original post: https://community.netweather.tv/topic/99706-model-output-discussion-into-2024/?do=findComment&comment=4994619

[Model Output Discussion - Into 2024]

Whilst quiet in here(?), I did some work back in 2018 on most of the severe cold spells since 1860 showing where/what  they came from and what was the temps (850's) in the region the outbreaks occurred (generally Iceland for northern based and 'Moscow' for eastern based) ln and what was the CET as a result.

I did this by examination of the reanalysis charts after consulting people on the web (and in here) about what cold outbreaks to include.

I tried to publish the data, but couldn't do it properly, I might try again soon now if I can find the data. 

Anyway I still have the hardcopy and I am checking the data, and I give the relevant data in summary below.......

 I organised it in month order -  

During November, until Nov 2010 (Greenland based) there were very few other cold spells (3  - in 1978, 1904 and 1890.  (temps of 850 in 2010 was -14C, but fell to -20C at source,     CET -1.9C)

In December - 25 occurrences  mostly from straight northerlies. Greenland 'forced'   - a few of them, but mostly easterly based. when -28C  (in Dec 1892) was the coldest source and the CET was --3.12C).

Most Greenies started as a UK high and the coldest 850''s was in 1927 and 1892 when -24C was the 850.  These produced CET's of 

--2.6 and -3.37C respectively.

 

So onto January - when I recorded 31 cold spells.

Most based upon Siberian highs after Northerlies and a UK high..

Greenland based were in 1987 (-3.0C) , 1982(-4.03C),  1963(-3.56C), nearly all the early 1940's,    coldest (-3.49 in 1940),   1894(_4,4C) ,  1881 (-4.38C) .

These were produced by the lowest Greeny based 850's of between -20C and -28C) from the air sourced above/over Iceland. 

850's over the UK were (associated with the colder outbreaks) between -14C and -18C, otherwise -10C to -14C.

Gives you an idea of what may be possible if things go according to way they are being shown today.

I also have data for February, March and April - but I will leave that for later!!!, 

This is not to say something  will happen - as there are many 'risks' to overcome first.

I also have some research into that looking at how many cold spells followed blizzards, but I will leave that to another post.

Hope the mods are happy me posting this on the model thread, but many people would like to know what is the 'worst/best ' we can expect.

MIA

 

[Snow and Ice Northern Hemisphere - Winter 23 /24]

2 hours ago, Metwatch said:

A quick question on this chart 

Does the temperature specified in the open waters equate to the temperature above the freezing point of salt water  (-1.8C), or is it the absolute temperature of the ocean.

I do not understand which it is and I cannot read the FInish (or Swedish) language to sort it out.

Also the isotherm lines seem to be in different places and I am not certain why.

 I guess it wont make any difference to the ice freezing, but it would be useful to know!!. 

MIA 

[Model Output Discussion - Into 2024]

5 minutes ago, Panayiotis said:

Although 10 days away, we just need to be careful with the heights being pulled from Africa (which moves over France then over us). For the real cold pattern this would need to be cut off ASAP otherwise there is a risk for high pressure developing over the UK which would shunt the cold away. 

Unlikely..

The  very cold air to the north moving down would either blow the warm air away OR make it rise producing a massive blizzard.

P29 ? described above is basically that scenario....

MIA

[Model Output Discussion - Into 2024]

45 minutes ago, on the coast said:

Thats a cold sea

-     Yep just done the first  ice report for the North Sea in the NH Snow and Ice thread 

MIA

[Snow and Ice Northern Hemisphere - Winter 23 /24]

Two days into the new year and with things looking interesting for next 2 week in the UK, I thought an update on the Arctic ice and snow might be useful for some...

Whilst snow is currently below average, I can see big changes next week with much colder air in both Europe and the north and west of the North American continent, bringing a lot of snow.

Sea ice is different though, with currently extent at near record levels for the last 20 years for overall, although this is caused mainly by excess ice outside the Arctic basin -   in the Pacific oceans.

Thanks to both Maise and  the ASIF (Jaxa) for the data below -

Masie extent is at a new high for the last 17 years currently (though its history is not totally pucka over 10 years),

 

with Baltic and Barents shown below -

       and        

Also Greenland ocean sea is fairly packed at the moment -

So any winds from the north and particularly the Baltic could carry an icy blast this year.

More detail of the Baltic is shown for today -

https://cdn.fmi.fi/marine-observations/products/ice-charts/latest-full-color-ice-chart.pdf  

and this will increase rapidly this week as -20C to  -40c air blows in from the northern Arctic waters. 

Just in case someone is not happy using Masie for ice detail, I show the Jaxa ice extents from today's reports -

    

This shows this year to be 18th out of the last 20 years.. Only last year and 2012 were better at this point in the year, and I expect that these  will be exceeded shortly as the momentum seems to be gaining this year. IF this does happen we will be looking at the 2000 average  (as well as 2010's already over-taken) being exceeded.

All very positive for the Northern hemisphere for  a cold outlook,

PS I'm all ready for  a North Sea  sea ice report!!!!!        

MIA

     

 

 

  

[Snow and Ice Northern Hemisphere - Winter 23 /24]

2 hours ago, cheese said:

I'm sure we will see a pretty big increase in Baltic Sea ice over the coming week with the very cold temperatures. The Swedish Meteorological institute has released multiple warnings for severe ice accretion in the Baltic. January is still pretty early in the season so it will be interesting to see how much ice actually forms. 

Yep already a big increase today   -

and now looking to move further south.

https://cdn.fmi.fi/marine-observations/products/ice-charts/latest-full-color-ice-chart.pdf

MIA

[Snow and Ice Northern Hemisphere - Winter 23 /24]

9 hours ago, Pauski said:

I am new here and  not posted before(only reading many years). I live in Finland,  Häme Castle(Hämeenlinna in finnish) is located in Finland in the city of the same name.

Häme Castle

WWW.KANSALLISMUSEO.FI

---

Experience the Middle Ages as well as the grandeur and decline of this 700-year-old castle by yourself or on a guided tour.

 

Welcome Pauski..

 It would be nice if  you could keep us informed of the status of the weather (together with the other newly registered  people) from Finland.

[Snow and Ice Northern Hemisphere - Winter 23 /24]

8 hours ago, hwyl said:

Häme Castle from the train window, ca -23 - perfect clear Nordic hp!

 

Hwyl...

Where is this taken? Is it by Stockholm on the Baltic?

Cheers MIA

 

[Snow and Ice Northern Hemisphere - Winter 23 /24]

and finally a snow and sea ice  comparison of end of 2022 with end of 2023 (for comparison) -

   <   2023          and 2022    >  

 

MIA

 

[Snow and Ice Northern Hemisphere - Winter 23 /24]

As discussed above I will do an end of 2023 post for both the Northern and Southern hemispheres sea ice now.  ( Worldwide is also interesting)

The post below is mainly taken from the ASIF (with thanks for the charts).

2023  started off more slowly than the end of 2022, with an end of refreeze update for 22/23 about in an average 6 - 9th position overall, but with the trends (see below for graphs)  on an increased slope.

 We then went through a rapid melt  in August at the end of the 2023 melting season. 

Sept and Oct were quite good for sea ice and by the end  of Nov were in an average position with the refreeze having taken over the basin slightly earlier than the average of the last few years. 

Since then the refreeze in the Pacific (outgoing sea areas) has been very strong and rapid.

Looking back at the sea ice extent average amount of sea ice or the NH we see -

 which has shown the higher amounts in the last 3 years and after the drop in the summer, it also shows well the uplift of the last 3weeks. The linear trend  lines of the last 10 years and the last 50 years are attempted to be shown -

So all looks very good really  - without suggesting any reasons for it.

It does seem to suggest that a breakout may well be happening but it requires another years data to confirm.

 

 

Meanwhile for the SH (Antarctica) things have been very different -

A rapid fall in the SH sea ice started in the Autumn of 2022 an this continued until about 3 - 4 months ago, when a recovery became apparent -

 ( I have already suggested it must be connected with  the Hunga Tonga Volcano).

and this is shown more clearly in the charts below for the accumulated amount of sea ice area shown at the end here -

       

So pretty large impacts of 'something' are being shown in the southern hemisphere.

 

What does this all mean for the worldwide Sea ice position?  Remember that this - according to some people  - is key to our continued life expectations on earth.

 

         

So what does the recent increases mean with the longer term trends in total sea ice area?

          

Again we need to see what happens this year to make any longer term statements, but the recovery in worldwide sea ice extent does appear to be quite strong at the moment.

A rapid 'bounce back' in the Antarctic area sea total annual sea ice area will be forthcoming soon as we are now at higher levels than last year right now. 

All for now, keep healthy and cheerful, and now for me back to the MAD thread. !!!

MIA