The Seasonal Forecast Thread

[Weather-history]

On 31 December 2015 at 7:48 PM, I remember Atlantic 252 said:

can only agree, I found Ian Brown quite accurate too

Well he's wrote off the netweather winter forecast, no SSW this January. And he's wrote it off under his name not one of his trolling aliases such as Billy Britain, Leyburn Weather, Melanie, Horse Man.....

 

Edited January 2, 2016 by Weather-history

[Nick L]

And frankly, anyone supporting his "accuracy" HAS to be on a wind up.

[VillagePlank]

The extraordinary December CET has bust many forecasts - including mine since the magnitude of what happened in Nov and Dec appears nowhere on the CET record - but here's the carry through from the statistical analogue method to March

 

 

Still average in February but getting colder through to March. I've also included each years Pearsons coefficient (r2) so one can see how closely each year statistical matched 2015. In this case I've only included years > 0.65. The variance in including years > 0.5 was to great to have any skill.

On the balance of experience, I'd suggest that 1710 was closer than 1954, which suggests a verycold February and less cold March. Looking at GFS forecasts out into FI, 1974 also looks like a good analogue particularly with it's warm December.

Edited January 2, 2016 by VillagePlank

[BLAST FROM THE PAST]

On ‎30‎/‎12‎/‎2015 at 0:49 PM, karyo said:

Thanks John, that's useful to know. I do value his opinion. I can't say I am pleased with having to wait till 2020 for a cold winter. Might have to make some winter trips to Scandinavia till then.

Karyo

I'll challenge that, the switch is already here re hemispheric pattern but for UK I think 2016 is the year of 'noticeable' change, also there is and proposed to be massive blocking over northern Russia?

 

BFTP

[karyo]

8 hours ago, BLAST FROM THE PAST said:

I'll challenge that, the switch is already here re hemispheric pattern but for UK I think 2016 is the year of 'noticeable' change, also there is and proposed to be massive blocking over northern Russia?

 

BFTP

So will this noticeable change happen soon enough to save a part of this winter or will we have to wait till December?

[BLAST FROM THE PAST]

2 hours ago, karyo said:

So will this noticeable change happen soon enough to save a part of this winter or will we have to wait till December?

I'm expecting some winter at end of Jan / early Feb but  already this Jan is looking 'better' than I anticipated with the block to our E further N than I had it, so who knows.  Certainly head turning times with more severe weather to come for sure, defo rain and gales, hopefully snow in there

 

BFTP

[karyo]

2 hours ago, BLAST FROM THE PAST said:

I'm expecting some winter at end of Jan / early Feb but  already this Jan is looking 'better' than I anticipated with the block to our E further N than I had it, so who knows.  Certainly head turning times with more severe weather to come for sure, defo rain and gales, hopefully snow in there

 

BFTP

Thanks for the explanation.

[BLAST FROM THE PAST]

8 hours ago, karyo said:

Thanks for the explanation.

To put eggs in one basket, my quote on 24th Dec for Jan

Quote

Towards very end of month entering into Feb is when I'm looking for change to an assault from the North

What I expect is a very potent assault from the north with polar lows.  Danger is that the far south could 'miss' the assault BUT I think some really unusually cold air to flood south ...which means big ridge to west and trough over North Sea and us.  2 week event approx

 

BFTP   

[Methuselah]

2 minutes ago, BLAST FROM THE PAST said:

To put eggs in one basket, my quote on 24th Dec for Jan

What I expect is a very potent assault from the north with polar lows.  Danger is that the far south could 'miss' the assault BUT I think some really unusually cold air to flood south ...which means big ridge to west and trough over North Sea and us.  2 week event approx

 

BFTP   

Will that be due to the full moon, the half-moon or gibbous moon, Fred? I'm a tad weak on these things...

[BLAST FROM THE PAST]

Now now Pete, lunar influence is a modulator not a driver...now how about you flippantly look at other forecasts

BFTP

[Methuselah]

1 minute ago, BLAST FROM THE PAST said:

Now now Pete, lunar influence is a modulator not a driver...now how about you flippantly look at other forecasts

BFTP

Happy New Year, Fred! I knew you wouldn't be able to resist!

[BLAST FROM THE PAST]

And to you Pete.....you git

 

BFTP

[Roger J Smith]

Trends have been a bit more extreme than predicted earlier (not very often that one predicts a very mild December and busts by 2 deg on the low side) but the general evolution seems to be on track for a gradual reversal of the pattern for western Europe. A critical time for deciding which theme will win out is around 20-25 Jan, if this period begins to show blocking tendencies, then a significant 2-3 week wintry spell would likely follow. If that period shows signs of renewing the December style mild spell, then blocking would probably be much weaker and only show up for a few days in February as with the 2007 snowfall event in that otherwise mild winter.

Either way I feel fairly confident in saying that there will be some significant cold and snow before all is said and done this winter. I would look to the period 4-8 Feb as being the most likely for snowfall in central and southern England.

[BLAST FROM THE PAST]

RJS

HNY to you.  What's your thoughts on the current modelling going on re cold spell midmonth ?  Nice if it comes off but seems on the extreme side?  well maybe it seems 'too favourable' ....but having said that this December was darn extreme for mild anomaly and already the blocking has been better placed this month for my outlook so it all looks possible.

 

BFTP

Edited January 4, 2016 by BLAST FROM THE PAST

[Roger J Smith]

If there are a few cold days (remains to be seen at this time range) mid-month then it will probably sharpen up the battle scenario expected (from research) 20-25 Jan which is when I would expect to see amplification and a general intensification of the hemispheric patterns which look rather flabby at the moment. I suppose we all do after the holidays.

 

 

[iapennell]

The weather has finally turned colder, a couple of days with north-westerlies from inside the Arctic Circle.  Early January 2016 has been wet and still quite mild- snow rather than rain and that is at over 400 metres up in the North Pennines, but at least we now have an inch of snow and it was -4C last night.

Looking at the weather charts it looks like the current cold snap will not last beyond the weekend- back to Westerlies next week.  I did not believe that a Sudden Stratospheric Warming high over the Arctic was going to occur and result in a bitterly cold January with weeks of hard frost and snowfalls, and lo- it hasn't happened!  In retrospect strong El-Ninos, the westerlies high up over the Equator (Quasi Biennial Oscillation) and the still-active phase of the sunspot cycle have conspired against blocking patterns occurring in high latitudes that would be required to lead to weeks of bitter north-east winds from northern Russia.

However, February remains the best bet for real cold snaps this winter, but these will be short sharp affairs delivered on northerly or NW winds from the Greenland Icecap, rather than weeks of bitter easterlies: The Jet-stream remains too strong for that. There is a possibility of cold northwesterly winds at times persisting into March too- particularly for those of us living in the North, this is thanks to a large patch of colder-than-normal water in the NW Atlantic close to 45N and the fact that- in the eastern North America and Greenland sector at least- Arctic pack-ice extends further south than usual. 

[iapennell]

This is a link to the pressure map for the end of January 2016:

Looks mild to me!

Edited January 15, 2016 by iapennell

[BLAST FROM THE PAST]

On ‎04‎/‎01‎/‎2016 at 1:16 AM, Roger J Smith said:

Trends have been a bit more extreme than predicted earlier (not very often that one predicts a very mild December and busts by 2 deg on the low side) but the general evolution seems to be on track for a gradual reversal of the pattern for western Europe. A critical time for deciding which theme will win out is around 20-25 Jan, if this period begins to show blocking tendencies, then a significant 2-3 week wintry spell would likely follow. If that period shows signs of renewing the December style mild spell, then blocking would probably be much weaker and only show up for a few days in February as with the 2007 snowfall event in that otherwise mild winter.

Either way I feel fairly confident in saying that there will be some significant cold and snow before all is said and done this winter. I would look to the period 4-8 Feb as being the most likely for snowfall in central and southern England.

Considering we agreed on the main  event early Feb very interesting model outlook today Roger.  I've been expecting the 'upgrade' in outlook as shown by some repetitive posts.  Your post is looking really good at the moment.  I've had some 'nearly' calls within the winter but you stuck to the overall pattern...correct call.  So February here we come, and I expect some winter and I don't anticipate having to wait until mid or second half either

 

regards

 

BFTP

Edited January 27, 2016 by BLAST FROM THE PAST

[Hocus Pocus]

On 15 January 2016 at 0:56 PM, iapennell said:

The weather has finally turned colder, a couple of days with north-westerlies from inside the Arctic Circle.  Early January 2016 has been wet and still quite mild- snow rather than rain and that is at over 400 metres up in the North Pennines, but at least we now have an inch of snow and it was -4C last night.

Looking at the weather charts it looks like the current cold snap will not last beyond the weekend- back to Westerlies next week.  I did not believe that a Sudden Stratospheric Warming high over the Arctic was going to occur and result in a bitterly cold January with weeks of hard frost and snowfalls, and lo- it hasn't happened!  In retrospect strong El-Ninos, the westerlies high up over the Equator (Quasi Biennial Oscillation) and the still-active phase of the sunspot cycle have conspired against blocking patterns occurring in high latitudes that would be required to lead to weeks of bitter north-east winds from northern Russia.

However, February remains the best bet for real cold snaps this winter, but these will be short sharp affairs delivered on northerly or NW winds from the Greenland Icecap, rather than weeks of bitter easterlies: The Jet-stream remains too strong for that. There is a possibility of cold northwesterly winds at times persisting into March too- particularly for those of us living in the North, this is thanks to a large patch of colder-than-normal water in the NW Atlantic close to 45N and the fact that- in the eastern North America and Greenland sector at least- Arctic pack-ice extends further south than usual. 

Looking at the MetO thoughts for the rest of this month and into March your LRF is almost identical Ian, add the proceeding months of your forecasts and you've scored another amazing coup with your efforts. Well done again Ian and more so if February pans out the way the MetO are suggesting, any early thoughts for next winter. 

[iapennell]

On 02/02/2016 at 10:02 AM, Hocus Pocus said:

Looking at the MetO thoughts for the rest of this month and into March your LRF is almost identical Ian, add the proceeding months of your forecasts and you've scored another amazing coup with your efforts. Well done again Ian and more so if February pans out the way the MetO are suggesting, any early thoughts for next winter. 

It is probably too far out to make reliable predictions given that quite a lot could happen to knock things off course over the next ten months: For instance the El Nino pattern could reverse and a massive volcanic eruption could happen throwing huge amounts of dust into the stratosphere and that would have a big effect on the global winds. If I was to offer a general hint I would suggest a slightly milder than normal winter but with a few sharp cold snaps, rainfall above normal but nothing like as wet as this winter has been to date.  I would make such a prediction on the basis of the likely end to El Nino by then and the current active phase of the Sunspot Cycle coming to an end. However CO2 levels are still rising so although an end to El Nino, etc suggests weaker westerlies next winter I would not (this far out) suggest a bitterly cold winter for 2016/17.

However much can happen over the next ten months to fundamentally change even such a general outlook such as a big volcano or persistent northerlies chilling the North Atlantic to an unprecedented degree. I will be making a prediction for Spring 2016 however. 

[Don]

26 minutes ago, iapennell said:

However CO2 levels are still rising so although an end to El Nino, etc suggests weaker westerlies next winter I would not (this far out) suggest a bitterly cold winter for 2016/17.

 

Hi Ian

Are you still thinking that we could get some colder winters towards the end of the decade as we move into solar minimum?

Thanks

[iapennell]

2 hours ago, Don said:

Hi Ian

Are you still thinking that we could get some colder winters towards the end of the decade as we move into solar minimum?

Thanks

Hi Don; Although I don't think next winter will be bitterly cold the Sun is predicted by  number of solar physicists to enter a prolonged quiet period following the end of the active phase of the current Sunspot Cycle (Schwabe Cycle number 24).  The Sun is due to enter a Maunder Minimum type of period lasting about 40 years and the average annual Solar Constant is likely to drop by about 0.25 percent by 2030. This is not such a big change in itself but it will certainly counter the effect of rising CO2 levels over the next 15 to 20 years, the big impact of such a quiet Sun is that the fall in radiation emitted is not uniform across all wavelengths, in the UV and high-end visible the drop off is two or three percent (in other words that portion of solar radiation that gets through to ground-level unimpeded when skies are clear). As such the cooling effect of such a quiet Sun will be profound at ground level and will considerably overcome any effects of rising CO2 levels over the next twenty years.  The Arctic pack-ice will extend further south and the wintertime Circumpolar Vortex will expand to lower latitudes.  This will lead to weaker westerlies and an increased incidence of blocking-patterns at higher latitudes by about 2030; so that means cold winters. But not yet!

[Hocus Pocus]

Fascinating stuff Ian, one point worth mentioning regarding our warming trend and that is what if the majority of this warming is natural. Of course we've no way of measuring just what percentage is anthropogenic and what is natural so would this not be needed to take into consideration on shorter timescales?

[knocker]

28 minutes ago, Hocus Pocus said:

Fascinating stuff Ian, one point worth mentioning regarding our warming trend and that is what if the majority of this warming is natural. Of course we've no way of measuring just what percentage is anthropogenic and what is natural so would this not be needed to take into consideration on shorter timescales?

Firstly, the hypothetical natural cycle would have to explain the observed "fingerprints" of greenhouse gas-induced warming. Even if, for the sake of argument, we were to discount the direct measurements showing an increased greenhouse effect, other lines of evidence point to anthropogenic causes. For example, the troposphere (the lowest part of the atmosphere) is warming, but the levels above, from the stratosphere up, are cooling, as less radiation is escaping out to space. This rules out cycles related to the Sun, as solar influences would warm the entire atmosphere in a uniform fashion. The only explanation that makes sense is greenhouse gases.

What about an internal cycle, perhaps from volcanoes or the ocean, that releases massive amounts of greenhouse gases? This wouldn't make sense either, not only because scientists keep track of volcanic and oceanic emissions of CO2 and know that they are small compared to anthropogenic emissions, but also because CO2 from fossil fuels has its own fingerprints. Its isotopic signature is depleted in the carbon-13 isotope, which explains why the atmospheric ratio of carbon-12 to carbon-13 has been going up as anthropogenic carbon dioxide goes up. Additionally, atmospheric oxygen (O2) is decreasing at the same rate that CO2 is increasing, because oxygen is consumed when fossil fuels combust.

A natural cycle that fits all these fingerprints is nearly unfathomable. However, that's not all the cycle would have to explain. It would also have to tell us why anthropogenic greenhouse gases are not having an effect. Either a century of basic physics and chemistry studying the radiative properties of greenhouse gases would have to be proven wrong, or the natural cycle would have to be unbelievably complex to prevent such dramatic anthropogenic emissions from warming the planet.

It is indeed possible that multidecadal climate variability, especially cycles originating in the Atlantic, could be contributing to recent warming, particularly in the Arctic. However, the amplitude of the cycles simply can't explain the observed temperature change. Internal variability has always been superimposed on top of global surface temperature trends, but the magnitude - as well as the fingerprints - of current warming clearly indicates that anthropogenic greenhouse gases are the dominant factor.

And

Feulner and Rahmstorf (2010) examined the impact on global warming if the sun fell into a Grand Solar Minimum.  The global mean temperature difference is shown for the time period 1900 to 2100 for the IPCC A2 emissions scenario (relative to zero for the average temperature during the years 1961 to 1990). The red line shows predicted temperature change for the current level of solar activity, the blue line shows predicted temperature change for solar activity at the much lower level of the Maunder Minimum, and the black line shows observed temperatures from the NASA GISS dataset through 2010.  The authors found that the average global surface temperature would be diminished by no more than 0.3°C due to the lower solar activity, which would offset only a small fraction of human-caused global warming.

http://www.skepticalscience.com/graphics.php?g=21

Edited February 4, 2016 by knocker

[Hocus Pocus]

II'm referring to just what amount of warming is anthropogenic, no one really knows knocker it could all of the 0.8c rise over 150 years or a fraction of that.