WINTER 2014 / 15 PRELIMINARY VIEW - * COLD , POSSIBLY VERY COLD + DRIER THAN AVE *

[Lynxus]

Not sure if this is the best place, However this an interesting read  Re: the ultra cold that the east is having recently..

 

http://news.sciencemag.org/asia/2014/10/arctic-sea-ice-loss-responsible-eurasias-deep-chill

 

 

 

From the article:

A deadly winter cold wave settled over Europe at the end of January 2012, blanketing much of the continent with snow and ultimately causing more than 800 deaths. Such severe winters are becoming more common across Eurasia—and some scientists contend that sea ice loss, by altering circulation patterns, is ultimately to blame for these frequent deep chills. But as climate simulations haven’t yet parsed out the atmospheric response to the loss of sea ice, its influence on Eurasian winters remains a question mark. Now, a new modeling study finds a link between these winters and the decline of sea ice in a part of the Arctic Ocean known as the Barents-Kara sea region, bordering Norway and Russia. The researchers identified several key circulation patterns that affected the winter temperatures from 1979 to 2013, particularly the Arctic Oscillation (a climate pattern that circulates around the Arctic Ocean and tends to confine colder air to the polar latitudes) and a second pattern they call Warm Arctic and Cold Eurasia (WACE), which they found correlates to sea ice loss as well as to particularly strong winters. WACE has been going strong since about 2004 or 2005—and as a result, the probability of severe winters has more than doubled in central Eurasia, they report online today in Nature Geoscience. But these severe winters may be a temporary phase within longer term warming: By the end of the century, the researchers report, the Arctic Oscillation could overpower the cooling effect from WACE—and winter temperatures over Eurasia will gradually increase.

Edited October 27, 2014 by Lynxus

[SMU]

I will catch up with the posts & comments later -

However the word

MADDEN is banned from this thread. The guys a tool.

[Lynxus]

I will catch up with the posts & comments later -

However the word

MADDEN is banned from this thread. The guys a tool.

 

Cough*   Tools are useful. In fact , This is somewhat offensive to tools.

[feb1991blizzard]

Excellent analysis as per usual Steve, me not being one of the most knowledgeable but I still did a lot of early compositing on other things than the OPI and came to a similar conclusion, couldn't post them as they just disappear on here and my laptop has bust now anyway so cant access it at all, anyway the upshot was I came to the conclusion that a cold spell could hit slightly earlier and suggest 15th Dec - 15th Jan the real chance of bitter cold, although mine came out a zonal first 2 thirds of Nov and would suggest history would say that wouldn't necessarily be a bad thing.

[summer blizzard]

All i ask for is the 15th Jan-25th Jan 2013.. as a ten day period that was cracking.

 

Good forecast Steve.

Edited October 27, 2014 by summer blizzard

[MR EXTREMES]

Steve

Some bad news, really bad news........Madden has forecast a really cold winter AND chosen January as the coldest most wintry month.      

I hope that doesn't put the mockers on it

 

Oh, yours has sound reasoning....that'll be the difference

 

BFTP

even more bad new the most depressing news this year the met office ideas of this winter im hiding behind the sofa. 

[MR EXTREMES]

Not sure if this is the best place, However this an interesting read  Re: the ultra cold that the east is having recently..

 

http://news.sciencemag.org/asia/2014/10/arctic-sea-ice-loss-responsible-eurasias-deep-chill

 

 

 

From the article:

A deadly winter cold wave settled over Europe at the end of January 2012, blanketing much of the continent with snow and ultimately causing more than 800 deaths. Such severe winters are becoming more common across Eurasia—and some scientists contend that sea ice loss, by altering circulation patterns, is ultimately to blame for these frequent deep chills. But as climate simulations haven’t yet parsed out the atmospheric response to the loss of sea ice, its influence on Eurasian winters remains a question mark. Now, a new modeling study finds a link between these winters and the decline of sea ice in a part of the Arctic Ocean known as the Barents-Kara sea region, bordering Norway and Russia. The researchers identified several key circulation patterns that affected the winter temperatures from 1979 to 2013, particularly the Arctic Oscillation (a climate pattern that circulates around the Arctic Ocean and tends to confine colder air to the polar latitudes) and a second pattern they call Warm Arctic and Cold Eurasia (WACE), which they found correlates to sea ice loss as well as to particularly strong winters. WACE has been going strong since about 2004 or 2005—and as a result, the probability of severe winters has more than doubled in central Eurasia, they report online today in Nature Geoscience. But these severe winters may be a temporary phase within longer term warming: By the end of the century, the researchers report, the Arctic Oscillation could overpower the cooling effect from WACE—and winter temperatures over Eurasia will gradually increase.

 

summer suns met office ideas on this years sea ice..... 

In the Arctic, sea ice is growing and is a little below average across the basin as a whole. Sea ice extent to the northeast of Russia is well below average, whilst closer to Europe, in the Kara Sea, the extent is close to average for the time of year

[Polar Side]

Really enjoyed reading your preliminary forecast, excellent analysis as usual.

Steve, do you think the long range seasonal models will start to pick up on the signal for a cold winter ?

[A.J]

Really enjoyed reading your preliminary forecast, excellent analysis as usual.

Steve, do you think the long range seasonal models will start to pick up on the signal for a cold winter ?

haven't checked the raw CFS  output today, but certainly noticed a couple of days ago it was a pretty blocked scenario with solid HP over Scandinavia into Russia for a good chunk of the winter

 

a really in-depth analysis/forecast from SM, a thumbs up from everyone I think for him taking the time to compile his analysis

[Don]

even more bad new the most depressing news this year the met office ideas of this winter im hiding behind the sofa. 

 

It only goes to January and it does mention an increasing chance of colder outbreaks later on, so all is not lost and after last Winter, I think many would take that, even if we we're not looking at another 2009/10.  

[Froze were the Days]

haven't checked the raw CFS  output today, but certainly noticed a couple of days ago it was a pretty blocked scenario with solid HP over Scandinavia into Russia for a good chunk of the winter

 

a really in-depth analysis/forecast from SM, a thumbs up from everyone I think for him taking the time to compile his analysis

CFS raw output the last day or so has reverted back to low pressure going 'mental' in the Atlantic - dartboard lows at 950mb etc. frequently to the west and north west of the UK - in other words CFS not really picking up on any blocking of any note.

[mcweather]

A really well reasoned piece of work Steve. I look forward to your final winter forecast later in November.

[loafer]

Thank you Steve - your input and analysis is one of the key reasons this is my weather site of choice.

[Methuselah]

No one knows. Including me.

[yido]

Fantastic read Steve as usual. Your ability to present data that to many (me included) would be seen as little more than mumbo jumbo is second to none. Fingers crossed your caveats don't come into play and a cold snowy winter lies ahead.

Net Weather is very lucky to have your membership as are all us mere mortals!!!

[SMU]

Evening All....

 

" Ice age ready to grip Europe....... "

 

 

Well not quite. -

 

 

The SAI Index is nearly complete for the month of October & the data suggests this October will be the most fruitful in terms of snow advancement we have ever had.

 

 

So whats driving this & is it a cause or an effect.

 

Well Cohens work is well known in terms of Feedbacks into the Winter time tropospheric > stratospheric relationship- here it is below-

 

 

We understand that the Snowcover index becomes an influence around the Strength of the vortex, but what about the associated Height anomalies arising from this increase & could the effects become more elongated towards the UK?

 

 

Well we start with the route cause of this which is the sea ice anomaly.

 

Look at this image of where the Anomalies lie ( image courtesy of ICDC )

 

 

This is clearly indicated in the surface air temperature anomaly in the polar region extending South into Northern Siberia.

 

 

The surface air temperature being strongly positive is one 'spin off' from the melted ice, however the other is the amount of moisture in the air, that is then translated in available moisture in Late September & through October.

 

Here the image shows the relative humidity anomaly @ 925MB in the lowest part of the atmosphere since 2007 when we had the first crash in cover & volume.

 

 

Look close at the SAME area as where the big ice anomaly is & you see that the humidity gains are circa 10-15% V the 1948-current Norm.

 

Now the surface Temp Anomaly is driving a LARGE feedback loop specifically focussed on the Northern tip of Siberia ( referred to as the Taymyr peninsula ) where we see irregular heights developing in October - this is because of the much higher thickness of the warmer air.

 

The image below is the long term October height Mean from 1948-2007 & shows the order of magnitude of change.

 

 

We see the Taymyr region is firmly entrenched within the tight vortex circulation.

 

Now look at the height anomaly since 2009-

 

 

If we look close, the height anomaly is STARK for the Taymyr region & extending around the pole, also is becoming apparent teleconnection to lower heights scandi South ( & coincidentally why the UK is getting Warmer in October on the back of Southerly Winds)

Anyway look at the 850 temp Anomaly for these 4 years-

 

 

We can see whilst there isn't what I would call a significant anomaly across ALL years we are starting to see a picture of a move towards the cold air being shunted South then west out of the pole.

 

Now lets examine 2014 under the spotlight up to 26th-

 

How much of a shunt West is the Polar air getting- wow that's a -15c degree departure out of the pole into the SW part of Russia -

 

& the relative humidity-

 

 

Notably 10-15% increase in the area with the big cold anomaly.

 

So it is no surprise we have been heading for a VERY high SAI & across the piste this is something that will probably continue unabated until the pendulum swings to positive ice- which could be 20-30 years.

So the anomalies in the areas above will continue to increase in terms of depth which suggests that the SAI will increase & also the extension west of the cold air will also extend west into Scandi in October.

 

This then overall impacts the stratospheric vortex more & more to the point that the Base location of the Siberian High follows the snow- IE WEST.

( with the caveat that this anomaly is supported in October with other elements like the QBO )

 

It has been suggested that this whole feedback COULD move MORE western parts of Europe into that type of polar continental Winter with the core of the winds blowing from the east & as ever the UK will be tagging onto that at the western fringe.

 

Does it effect us? - well yes, as that fringe that we are on will always welcome a jog west so we are not so far out of reach of the deep Eastern European cold!

 

Effects for this Winter -  Combined with the supporting OPI index, the predisposed Atmosphere primed for Northern Blocking this feedback should precipitate further increased frequency & likelihood of the Arctic high becoming an Extension of the Siberian high Across Svalbard effecting the UK..............

 

regards

Steve
 

 

[joggs]

You gotta read me my bedtime story Steve lol.

Great read that!

[bobbydog]

Evening All....

 

" Ice age ready to grip Europe....... "

 

 

Well not quite. -

 

 

The SAI Index is nearly complete for the month of October & the data suggests this October will be the most fruitful in terms of snow advancement we have ever had.

 

SAI index2014.png

 

So whats driving this & is it a cause or an effect.

 

Well Cohens work is well known in terms of Feedbacks into the Winter time tropospheric > stratospheric relationship- here it is below-

 

Snowforedsignal.jpg

Cohen Snow.png

 

We understand that the Snowcover index becomes an influence around the Strength of the vortex, but what about the associated Height anomalies arising from this increase & could the effects become more elongated towards the UK?

 

 

Well we start with the route cause of this which is the sea ice anomaly.

 

Look at this image of where the Anomalies lie ( image courtesy of ICDC )

 

Ice anomaly.png

 

This is clearly indicated in the surface air temperature anomaly in the polar region extending South into Northern Siberia.

 

Surface Air anomaly.png

 

The surface air temperature being strongly positive is one 'spin off' from the melted ice, however the other is the amount of moisture in the air, that is then translated in available moisture in Late September & through October.

 

Here the image shows the relative humidity anomaly @ 925MB in the lowest part of the atmosphere since 2007 when we had the first crash in cover & volume.

 

Relative Humidity.png

 

Look close at the SAME area as where the big ice anomaly is & you see that the humidity gains are circa 10-15% V the 1948-current Norm.

 

Now the surface Temp Anomaly is driving a LARGE feedback loop specifically focussed on the Northern tip of Siberia ( referred to as the Taymyr peninsula ) where we see irregular heights developing in October - this is because of the much higher thickness of the warmer air.

 

The image below is the long term October height Mean from 1948-2007 & shows the order of magnitude of change.

 

October mean.png

 

We see the Taymyr region is firmly entrenched within the tight vortex circulation.

 

Now look at the height anomaly since 2009-

 

oCT hEIGHT aNOMALY.png

 

If we look close, the height anomaly is STARK for the Taymyr region & extending around the pole, also is becoming apparent teleconnection to lower heights scandi South ( & coincidentally why the UK is getting Warmer in October on the back of Southerly Winds)

Anyway look at the 850 temp Anomaly for these 4 years-

 

Oct Temp Anomaly.png

 

We can see whilst there isn't what I would call a significant anomaly across ALL years we are starting to see a picture of a move towards the cold air being shunted South then west out of the pole.

 

Now lets examine 2014 under the spotlight up to 26th-

 

How much of a shunt West is the Polar air getting- wow that's a -15c degree departure out of the pole into the SW part of Russia -

Oct 14.gif

 

& the relative humidity-

 

Oct 14 rel.gif

 

Notably 10-15% increase in the area with the big cold anomaly.

 

So it is no surprise we have been heading for a VERY high SAI & across the piste this is something that will probably continue unabated until the pendulum swings to positive ice- which could be 20-30 years.

So the anomalies in the areas above will continue to increase in terms of depth which suggests that the SAI will increase & also the extension west of the cold air will also extend west into Scandi in October.

 

This then overall impacts the stratospheric vortex more & more to the point that the Base location of the Siberian High follows the snow- IE WEST.

( with the caveat that this anomaly is supported in October with other elements like the QBO )

 

It has been suggested that this whole feedback COULD move MORE western parts of Europe into that type of polar continental Winter with the core of the winds blowing from the east & as ever the UK will be tagging onto that at the western fringe.

 

Does it effect us? - well yes, as that fringe that we are on will always welcome a jog west so we are not so far out of reach of the deep Eastern European cold!

 

Effects for this Winter -  Combined with the supporting OPI index, the predisposed Atmosphere primed for Northern Blocking this feedback should precipitate further increased frequency & likelihood of the Arctic high becoming an Extension of the Siberian high Across Svalbard effecting the UK..............

 

regards

Steve

Said James Madden yesterday

......

[Penrith Snow]

Fantastic Steve, some really good analysis their taking into account all the broad scale features.

To me this type of long range forecasting is so much better than merely running a computer model forward 4 months then taking the Ensemble mean which essentially is what the MetO does, that even with MRF is so prone to errors and the butterfly effect.

I am really confident of a very cold winter in 2014/15, I have only ever issued a winter forecast in 2009 and 2011 because of the strong signals at the time and got it more or less right both years (cold in 2009/10 mild in 2011/12) and I am equally confident this year that winter 2014/15 will be cold.

By the way I sat on the fence in other recent years because I thought signals were too conflicting so I don't think I could ever make it a career of it!

Let the countdown begin.

Andy

[SMU]

The changing modality of the AO -   From Neutral to Sharp Negative.

 

 

In the grand Scheme of Northern Hemisphere the AO ( or the MODE ) of the AO 'generally' dictates our weather with a fairly robust correlation up to about 0.7 to the UK ( via the NAO )

 

Its helpful to understand what a 'modality' change is going from one mode to another- so for bobbing along at +1, through Neutral to say -4.

 

Its all very well people posting links of the NOAA AO ensembles but it helps the underpinning knowledge.

 

Here is the image of the AO ensembles I posted today-

 

  If we look at where the index ends up then -3 is certainly something that catch our attention-

 

lets examine our ranked CET DATA for very cold months that we have data for ( post 48)

 

http://www.metoffice.gov.uk/hadobs/hadcet/mly_cet_mean_sort.txt

 

we get: ( no surprises ) with the monthly AO data adjacent...

 

Dec 10  -2.6

Dec 81  -1.2

Jan 63   -3.3

Feb 56   -2.0

Feb 63   -1.7  

Feb 87   -2.9

 

** NB.  relative to the long term mean a low value for December AO is harder to achieve because this is the month the PV & Jet is at its strongest & gradually weakens out in Feb -

relative to the month then , anything sub -2 in Dec or Even November is inverse to the Norm. **

 

 

Back to the original theme then the current ensembles going from +1 to -4, what does it look like- we need 3 things to visualize what that looks like.

 

* what the average loading pattern is -

* what +1 & -4 look like

* a data set that links the above numbers.

 

Heres the loading pattern:

which is your average +1.5 index.

 

Obviously the key areas to see height changes are-

POLE ( for positive heights)

PACIFIC ( For negative anomalies )
ATLANTIC to Iberia ( for Negative Anomalies )

 

 

Dataset then, 14th DEC 1978 to 27th DEC 1978 - a 5.7 Swing across 13 days.

 

1978 12 14  1.445
1978 12 15  0.541
1978 12 16  0.503
1978 12 17  0.674
1978 12 18  0.960
1978 12 19 -0.125
1978 12 20 -0.937
1978 12 21 -1.192
1978 12 22 -1.522
1978 12 23 -1.551
1978 12 24 -1.573
1978 12 25 -2.607
1978 12 26 -3.588
1978 12 27 -4.292

 

 

Starting out on the 14th of Dec the jet is pretty solid November pattern - the PV is generally circular although not as sinuous as other years, but a fairly insignificant:

 

 

wind on 4 days to the 19th- 

So we are looking for a ridge to start pushing into the pole- this will disrupt the vortex & start to throw negative anomalies to the regions we want.   - Note the most acute angle is towards Greenland... 

 

 

The next day the 20th the angle is so acute towards Greenland that its inevitable the WAA will drive a nice this High in the region- today is the first -1 index.

 

 

To get from -1 to -1.5 index we see further developments over pole on the 22nd. - with a cut off high forcing cold air south into the mid latitudes. Notice the big negative anomaly driving that index, but not so apparent across the atlantic etc.

We will need to go again with another ridge to crank downwards.

 

 

Well for the next 3 days the Pattern stays in Situ but gradually the systems rolling off the States decrease the heights over the atlantic - thus supporting the negativity.

Notice the Greenland high also supports the vortex creeping West around the NH on the negative zonal wind-

 

 

The 27th Sees a big ridge sucked North out of Alaska, this the next step change moving the AO downwards to a super AO. The forcing of that Second ridge is creating a wave of energy that's pushing the cold upstream through the mid latitude that's because the HIGH pressure steers the low pressure -

When the 2 highs combine over the pole any positive anomaly over Europe will soon reverse.

the 27th was the most negative in AO @ -4.2, although the 28th is close @ -4.1.

 

 

& finally the 28th sees the transition complete with the AO at -4 & a near full reverse circulation around the pole from Alaska to Norway

A -4 AO used to be rare, however since the ice anomaly has developed this stark anomaly has increased in frequency as this negative Ice anomaly is acting as an offset towards overall negative behaviours....

 

 

 

 

So heres the jackpot chart- 3 days Later.

 

Snow, Blizzards, sub Zero temps & 60 MPH easterly Winds.

 

 

& a quote from Trevor Harley ( website britweather years )

 

 

1978 The start of a memorable winter: the Winter of Discontent was also often cold and snowy. The were frequent gales early in the month. On the 13th, there was a damaging hailstorm in south Devon. Some snowalls in the week before Christmas, although Christmas itself was mild and dominated by SW winds and heavy rain. The Scandinavian blocking high was then in place at the end of the month, laying the ground work for the severe winter to come. The cold winter started on the 28th, when there was a marked contrast on the 28th: maximum of 14C in Guernsey, but beneath freezing all day in parts of Scotland. There were 255 mm of rain in 48 hours over the Mountains of Mourne at this time. The floodwaters in northern England froze, and snow fell on top. A severe blizzard struck southern England on the 30-31st, with deep drifting. New Year's Eve was the coldest for 40 years, with local maxima of -4C.

 

thanks for looking.....

 

S

[Allseasons-Si]

One word Steve

 

fantastic.

[weathergeek]

Steve I barely know anything about the scientific/technical side of weather/forecasting (just a humble Mum of 3!) but have come on NW for the last 3yrs to read about any signs for snow! I still don't fully understand your posts but always enjoy reading them and you always help to explain it in the simplist of terms! I'm nowhere near knowledgeable but have learnt a lot so in my 4th year here and having followed your comments on the OPI thread too, I'd like to say thank you and keep up the good work!!x

[hillbilly]

A brave effort for such a long range forcast but as with all long range forcasts it is a certain failure.Good LUCK !!

[feb1991blizzard]

A brave effort for such a long range forcast but as with all long range forcasts it is a certain failure.Good LUCK !!

 

Its got a better chance of happening than a winter like last year.

[The PIT]

AO looks even better today really tanks downwards. NAO heads more towards neutral. Interesting.