The Winter 2011/12 Forecast Thread

[johnholmes]

This is NOT a forecast but an interesting bit of research into 'mild' Decembers' since 1900 and what followed.

Worth a look and it will be interesting to see the responses; half full or half empty glasses!

CET values in December of 6.0 C and following jan-feb-30 dec 11.doc

[cyclonic happiness]

This is NOT a forecast but an interesting bit of research into 'mild' Decembers' since 1900 and what followed.

Worth a look and it will be interesting to see the responses; half full or half empty glasses!

CET values in December of 6.0 C and following jan-feb-30 dec 11.doc

Nice bit of work there John.

So what it really goes to show is that the winter can still go either way which is a good thingas it may stop the Netweather members from forming such a long queue at Beachy Head.

I really don't think it's been all that bad this winter, one always has to look at the positives and the best one being that, with so much Atlantic dominated weather, the Midlands and East Anglia are going to have a much better chance of refreshing their aquafers and water tables.

Anything remotely cold or from a cold direction tends to render our regions bone dry, so we really have to be greatful for this period of wet weather, I know I am.

[cooling climate]

This is NOT a forecast but an interesting bit of research into 'mild' Decembers' since 1900 and what followed.

Worth a look and it will be interesting to see the responses; half full or half empty glasses!

CET values in December of 6.0 C and following jan-feb-30 dec 11.doc

Very interesting, It would have been great if enso and QBO states

could have been added to give a bigger picture of what was happening

in the atmosphere.

PS February 1985, and 86 are the wrong way round. 86 of course being the

last negative cet month prior to December 2010.

[damianslaw]

Very interesting, It would have been great if enso and QBO states

could have been added to give a bigger picture of what was happening

in the atmosphere.

PS February 1985, and 86 are the wrong way round. 86 of course being the

last negative cet month prior to December 2010.

Interesting stats- no clear pattern neither. Interesting to see how 1985 and 1986 turned out. Isn't the ENSO state very similiar this year to those two years?

[johnholmes]

Very interesting, It would have been great if enso and QBO states

could have been added to give a bigger picture of what was happening

in the atmosphere.

well there is a little job for you cc, add the data you would like to have seen on there!

and the actual values copied from the CET site

sorry Net Wx does not like excel type tables, I'll try and post either a link for all to see or a pdf of the bit needed

the link to the CET site

http://www.personal....av_temperat.htm

re your 'cor to my data cc, I think you failed to read this

First col=year for December, 2^nd=December,

thus the first column is the year followed by data for December of that year followed by that for January and February for the following year?

Edited December 30, 2011 by johnholmes

[Tom Quintavalle]

Evening all,

Wont go into too much detail, otherwise I'll steal C.Cs thunder! Since 1950, looking at those mild Decembers John H researched, we've had 6 El Nino events and 5 La Ninas of varying strengths.

Yes C.C, 1985 gave a La Nina DJF figure of -0.9 and 1986 gave a La Nina DJF of -0.5. Havnt got time to post more extensively, just to say that yet again, as the CET result showed, the ENSO state showed no bias.

I'll let you post your findings C.C, on all those years John researched, perhaps the QBO state was more important in those years mentioned.

Regards,

Tom

Edited December 30, 2011 by TomSE20

[johnholmes]

Evening all,

Wont go into too much detail, otherwise I'll steal C.Cs thunder! Since 1950, looking at those mild Decembers John H researched, we've had 6 El Nino events and 5 La Ninas of varying strengths.

Yes C.C, 1985 gave a La Nina DJF figure of -0.9 and 1986 gave a La Nina DJF of -0.5. Havnt got time to post more extensively, just to say that yet again, as the CET result showed, the ENSO state showed no bias.

I'll let you post your findings C.C, on all those years John researched, perhaps the QBO state was more important in those years mentioned.

Regards,

Tom

thanks Tom, yes and no again it seems?

perhaps one day someone MIGHT discover how to predict the weather accurately in all its forms from 1 hour to 1 month ahead-not in my lifetime that is for sure.

[Tom Quintavalle]

thanks Tom, yes and no again it seems?

perhaps one day someone MIGHT discover how to predict the weather accurately in all its forms from 1 hour to 1 month ahead-not in my lifetime that is for sure.

Thanks John,

Had to rush off out tonight, so had a very quick look. If I can ask a favour, do you have a link for ENSO events pre 1950, I only have this one:

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml

Perhaps C.C is taking a look at those years pre 1950, as well as the QBO situation for all those years you've mentioned.

Regards,

Tom.

[johnholmes]

Thanks John,

Had to rush off out tonight, so had a very quick look. If I can ask a favour, do you have a link for ENSO events pre 1950, I only have this one:

http://www.cpc.ncep....ensoyears.shtml

Perhaps C.C is taking a look at those years pre 1950, as well as the QBO situation for all those years you've mentioned.

Regards,

Tom.

morning Tom-sorry No I don't have any links

[Methuselah]

perhaps one day someone MIGHT discover how to predict the weather accurately in all its forms from 1 hour to 1 month ahead-not in my lifetime that is for sure.

Nor in mine, I suspect.

[johnholmes]

Nor in mine, I suspect.

I won't ask where the 'new' name comes from-no don't tell everyone it will only stir things up Pete(SS)

[leicsnow]

Mark Vogan's revised written forecast:

For the first time this winter, it appears truely Arctic air (not modified by the ocean) will work it's way into the mid-latitudes of North America and eastern Asia. Yes, we do remain in the positive indexes of both the NAO (North Atlantic Oscillation) and AO (Arctic Oscillation) with a progressive, generally zonal, stormy (wavy) pattern around the N. Hemisphere with 'shots of cold' seperated by mild, maritime air.

Up until now, we have seen relatively weak cold, highly moderated by the oceans and with a strongly positive Arctic Oscillation, this has held all the true Arctic air north of the circle.

However, recent weeks have showed warming of the stratosphere and this continues to do so at 10mb. It appears this warming is bleeding around the pole from Asia towards Alaska, displacing the coldest upper level air across to Europe but STOP, that doesn't mean we see a deep freeze, no! But it may suggest the Arctic Oscillation may be heading towards neutral and if this progress continues the way it is, then it could well turn negative. Negative meaning, the polar vortex is weak and split, allowing ridges pushing north to reach and pull down pieces of this Arctic air.

This will be visible NEXT WEEK as we see the first true (albeit relatively short lived) Arctic outbreak plunge into the Central and Eastern US from Sunday through Thursday. During this same period, a push of Arctic air will also push south from Siberia into China where here too, the coldest air will arrive.

These lobes or fingers of true Arctic air are being allowed to branch off from the vortex, likely due to this warming of the upper levels. This gradual cooling of the troposphere beneath the stratosphere, allows the cold down to the surface and interestingly, where that warming is taking place, so the Arctic air is going to.

Yes, that means that with displacement of the coldest air aloft heading across to our part of the world, this suggests we WON'T see anything too terrible just yet with likely some brief shots of still-modified cold quickly followed by milder air, afterall, we don't yet have a negative NAO to show for the high building north from the N. Atlantic up over Greenland and therefore air will continue to free flow across us from the west.

It's the same for eastern North America that despite a bitter chill next week, this will be quickly followed by milder air again by weeksend simply because there's no stone (blocking highs) to stop the progressive west-east flow across the hemisphere.

The good news is, that whilst the evidence is there of change, this progress takes time and it's likely that if it continues, we will see more and more Arctic air reach the mid-latitudes and the return to a negative AO which may lead to the development of a negative NAO and the ultimate blocking pattern needed for a locked down period of cold. This will allow us to turn a LOT colder and remain that way for perhaps a few weeks.

I believe that given the current pattern and where we're at just now, I recon by Jan 15th through 20th and leading us into the late January period, we may well see a very different weather pattern over us which may present a challenging February and possibly March ahead.

The big concern is, IF we see this THEORY become a reality, then with such a long period of building cold thanks to the strong and persistent positive AO, then once that cold arrives, it may be much stronger than what we endured both last year and in 09-10. As well as that, could the NAO, again IF it does flip, last as long in a negative state as it did in a positive? If so, we may still see, one of the worst winters any of us have ever seen, deeming the last two mere curtain raisers. This is all very speculative and likely could be put down as hype, however, I like to share my thoughts with you and POTENTIALS with this pattern.

http://markvoganweather.blogspot.com/

Edited December 31, 2011 by Tellow

[johnholmes]

cooling climate, on 30 December 2011 - 14:27 , said:

Very interesting, It would have been great if enso and QBO states

could have been added to give a bigger picture of what was happening

in the atmosphere.

just wondering cooling climate if you will have a shot at this please?

It could make an interesting read for us all.

[bluearmy]

well mr vogan has finally released something that seems to make sense based on strat and trop modelling. however, he does tend to spoil it somewhat by sensationalising it later on.

[cooling climate]

cooling climate, on 30 December 2011 - 14:27 , said:

Very interesting, It would have been great if enso and QBO states

could have been added to give a bigger picture of what was happening

in the atmosphere.

just wondering cooling climate if you will have a shot at this please?

It could make an interesting read for us all.

I said it would have been interesting if we could have seen the enso

and QBO states (especially the QBO) to go along side the CET

figures knowing that of course we can not because the QBO statistics

to my knowledge only goes back to 1948 and the fiqures given back

then are very suspect given that they show a run of 7 - QBO winters.

As far as enso stats go again I think they only go back to around 1950

or so.

[Freezing-Point]

_{Basic Statistics of data sets -}

_{Variable N N* Mean SE Mean StDev Minimum Q1 Median Q3 Maximum}

_{Dec 20 0 6.750 0.131 0.587 6.000 6.325 6.650 6.900 8.100}

_{Jan 20 0 4.075 0.331 1.479 0.800 3.100 3.750 4.875 7.000}

_{Feb 20 0 4.040 0.431 1.927 -1.100 2.650 4.400 5.700 6.500}

_{Here is a run chart of the data.}

_{Points of note -}

1. _{Only once has the CET in either Jan or Feb been higher that the Dec CET (2006)}
   
2. Both Dec and Jan are both normal datasets (passed normality test), but the Feb data is not normal. The run chart below shows that clustering and trends are present (p-value <0.05).
   

Edited January 1, 2012 by Freezing-Point

[johnholmes]

thanks for that-an interesting way of showing the basic data.

[phil nw.]

I won't ask where the 'new' name comes from-no don't tell everyone it will only stir things up Pete(SS)

I think you ought to press him on it John--give him a good grilling.

[Tom Quintavalle]

CET values in December of 6.0C or more and what followed from 1900 onwards

I thought it would be interesting to see what this might show. Before starting it I had no idea how it might turn out. I used 6.0C or higher as that looks about the value for this December, around 6.0C or a bit above.

First col=year for December, 2^nd=December, 3^rd=January, 4^th= February; temperatures in degrees C

The averages are as per CET link taking 1971-2000 for average values

December=5.1C; January=4.2C; February=4.2C

1900 7.2 3.5 2.3

1910 6.4 3.8 4.8

1911 6.2 3.6 5.4

1912 6.7 4.5 4.8

1918 6.9 2.9 1.9

1921 6.5 3.7 4.4

1924 6.8 5.3 5.2

1934 8.1 4.5 5.8

1942 6.7 4.9 6.1

1953 6.9 2.9 2.6

1954 6.8 2.6 1.2

1959 6.0 3.0 4.1

1971 6.6 3.9 4.3

1974 8.1 6.8 4.4

1977 6.1 3.4 2.8

1985 6.3 3.5 -1.1

1986 6.3 0.8 3.6

1988 7.5 6.1 5.9

1994 6.4 4.8 6.5

2006 6.5 7.0 5.8

So a total of 20 winters with a mixed couple of months following.

Eight January+February were above normal plus 2February’s alone

Eight January and February were below average with an additional 4 January’s also below.

In total out of 40 months after December 18 were above average and 20 were below average with 2 just marginally above the 1971-2000 average.

Make of that what you will. They are the facts.

My apologies if anyone goes checking and finds any errors.

Above I've posted John Holmes research into Decembers that recorded a CET of at least 6.0c, firmly into the mild category.

Keeping the fact in mind that this is a miniscule sample, it's interesting to note that in those examples where Dec. had a CET of at least 6.0c and Jan recorded more than 4.2c (i.e the ave 1971-2000 CET.), in each of the following Februarys (8 in total), recorded a CET of more than 4.2c (the Feb CET average).

Tiny, tiny sample but interesting nevertheless. Here's hoping for a pattern change soon, cold inversion highs will do!

Anyway, I'm sure it's not conclusive. There's more of a mixed result when Jans CET was less than 4.2c,this occured on 12 occassions with a bias towards a colder than normal Feb, 8 colder than ave., 4 milder than ave.

Regards,

Tom.

[Methuselah]

I think you ought to press him on it John--give him a good grilling.

lol!

[VillagePlank]

Comparison to previous years (in my case the complete record) was how my winter forecast was done - ie statistical analogue forecasting. Analysis against previous years suggest that this is about as successful as chance (maybe very marginally more)

About 1degC out for December, but I was really going for the 'shape' of the forecast. Jan CET = 7degC?

http://forum.netweat...ost__p__2152838

Still an exercise in luck, and I'll flog the method to the papers next year, then retire, after receiving plaudits, and a Nobel prize to boot, at what a genius I am to use basic statistical methods to forecast the weather months ahead when everyone else discarded them years ago in preference to tea leaves, the moon, the stars, and an undergraduate degree course.

Edited January 4, 2012 by Boar Wrinklestorm

[Methuselah]

Comparison to previous years (in my case the complete record) was how my winter forecast was done - ie statistical analogue forecasting. Analysis against previous years suggest that this is about as successful as chance (maybe very marginally more)

About 1degC out for December, but I was really going for the 'shape' of the forecast. Jan CET = 7degC?

http://forum.netweat...ost__p__2152838

Still an exercise in luck, and I'll flog the method to the papers next year, then retire, after receiving plaudits, and a Nobel prize to boot, at what a genius I am to use basic statistical methods to forecast the weather months ahead when everyone else discarded them years ago in preference to tea leaves, the moon, the stars, and an undergraduate degree course.

Probably a more successful method than most of the others doing the rounds, BW. At least it's based on something...

[VillagePlank]

Yep - chance. Just about as successful as rolling a die and selecting three consecutive rolls as the CET for Dec, Jan, then Feb. Still, I'm sure I can hoodwink someone with it ...

[La Bise]

Give it a complicated name, be shady about it, accuse the MetOffice of being at the heart of a conspiracy to raise taxes and you'll be in business, certainly with the Mail and the Express...

[VillagePlank]

Correlative Covariance Clustering ?

The MetO almost certainly don't use such advanced technology, they concentrate on taxing me. The gits. I won't publish the details (nor skill/hit ratio) but I will claim that the forecast of 4.9C against an actual ~6C was a remarkable success. I mean there are an infinite amount of floating point numbers; look how good I am - just 1.1C out against the infinite set of numbers. I mean that really is close. Not only that, I forecast such mild temperatures in the face of government, media, and amateur forecast all predicting a below average CET. I mean this is sooo good, there must be something to it, after all.

Perhaps I should set up a website with a section for media enquiries?

Edited January 4, 2012 by Boar Wrinklestorm