Weak Nino’s With Cold PDO, Warm AMO In Autumn Often Mean US Cold, UK Warmth/Wet, Cold Winters Follow!

Written by on October 7, 2012 in United Kingdom & Ireland with 7 Comments

 

Loch Ard, Strilingshire, December 2009 (Courtesy of Mark Vogan)

 

While I am trying to figure out the pattern over the next few weeks, the best way I can explain what I am seeing right now is a seesaw with the continuation of an active Atlantic pattern, it’s a very up and down pattern. I am trying to understand how this pattern is evolving as we’re entering an important period in autumn.

I have stated my ideas on this autumn since August and made mention that we ‘should’ enter a relaxation period in which an anticyclone spends some time over us bringing settled weather with mild days and cool, frosty nights.

Glance at the week ahead

Interestingly, except for the southwestern parts of the UK, the majority have a fairly settled period which started yesterday (Saturday) and should last through at least Wednesday before stalled fronts manage to eventually work their way across the country bringing wet and windy weather as well as milder, muggier air up from the south. High pressure NORTH of the jet means cool, crisp days with plenty of sun followed by clear, cold, frosty nights. This includes Northern Ireland and much of the Republic. Perfect autumn weather. Mild, muggy, damp weather will persist across Devon, Cornwall, Dorset, Somerset as well as across South Wales also, much of this week starting today as a weather system tries to work up from the southwest. The high over Scotland and Northern England stops these fronts from going anywhere, so they’ll remain stuck over the southwest corner till late week when the high breaks down.

Here’s the GFS surface chart (MeteoGroup) through Wednesday..

What’s the current players and recent and current pattern telling us?

Because past weak El Nino Octobers have seen a period of rest within an overall active autumn I believe the next few weeks should display this. We may in fact be seeing this this week, I’m not sure. The US is seeing a cold October and this bodes well for a cold winter ahead there. Warm Octobers there have been known to be followed by warmer winters. As for here in Northwest Europe. We shouldn’t think that no winter weather in autumn should mean a mild or none eventful winter is on it’s way, in fact, going by recent years with weak El Ninos which are centrally positioned in the Pacific, a cold October in North America and a wet, relatively mild autumn in the UK, bodes well for a cold and snowy winter ahead. This happened back in 2009. The year 2009 is mentioned a lot these days because the pattern we’ve seen this summer, the El Nino state, the warm Atlantic, cold Pacific is very similar plus the NAO has trended similar too.

The big difference between this year and 2009 is the Atlantic is warmer and the Pacific is colder so the setup isn’t exactly the same. The nino is very alike but I am struggling to come up with anything right now that would suggest we don’t have a rather harsh and long winter ahead both here in Britain and Ireland as well as across the central and eastern US and Canada. EVERYTHING I am seeing right now points to a severe winter which could be just as severe as 2009-10. Keep in mind that 2009-10 is our benchmark for tough winters. It’s the worst since the 70s and we saw repeat cold and big snows all the way through LATE March. Heck it was even cold right up till mid-May when there was frosty mornings and highs struggled to hit 10C. It even snowed below 1,000ft. This year could be worse than 2009-10. There is a lot on the table.

While there are lots of sources either calling for a mild winter, going purely by what happened last year, in which case their not looking at anything or there’s folks calling for a 62-63 style winter. Lets be careful to not going for the extreme. It appears to happen every year since 2009.

In these posts, I am trying to show you WHY I am calling for what I am calling. I am trying to not go down the road of hype but looking at reality. In saying that, based on what trends I am seeing and correlation to the past, I am starting to lean more and more towards a harsher winter. Try not to pinpoint a particular winter and say that’s what’s going to happen but more look at what’s there and suggest, this is what COULD happen.

I may be contradicting myself because I am talking a lot about 2009-10 but my point is that it’s important to look at EVERYTHING and not just spout out what you want to see happen. Wishcasting is something which has become ripe in recent years. I guess I am trying to show you everything. By the time my winter forecast is out. You’ll already know what I believe is coming but more importantly, you’ll know why I’m calling it.

As for the lack of sea ice and chance of this providing us with a colder winter. I don’t see any relationship, the reason being that the arctic ocean closes back up with ice quickly. However, what I do think could very well have effect is that feedback to enhanced blocking and stronger stratospheric warming events. This is exactly what we had in 2009-10 winter here with the cold coming down and then staying here. We saw record or near record blocking in 2009-10 and with a warmer Atlantic this year, it begs the question whether we see even stronger blocking this year.

Crucial differences between 2011 and 2012 for UK

Here’s some crucial differences between this year and last. Never mind the fact there’s an El Nino rather than La Nina, there’s other vital differences which SHOULD mean cold, not warm this winter. 1) The NAO is trending opposite to last year. Where it wanted to always stay positive last year, it wants to stay negative this year 2) While there was a mean ridge over Britain last year with dry soils, there’s wet soils and a mean trough overhead this year. Last years dry soils and biased ridging over the UK lead to a feedback through the following winter 3) Warm waters surrounded Britain last year, this all fed back to the atmosphere keeping the warmth over us last winter 4) Warmest Atlantic waters are focused over the Northwest Atlantic so the block should be W, N of us and so the mean trough lasts through this winter. Difference between summer and winter is that trough will be filled with arctic air. You only have to look at past years and trends to see why the summer can be an important indicator in terms of mean positive and negative heights. Rainfall distribution.

Here’s the difference in water temperatures this year compared to this time last year.

October, 4, 2012

October 6, 2011

Important to note is the cold waters over the North Atlantic extending east to Ireland and west coast UK, warmth in the North Sea last year and this year where waters are cooler in the North Sea, warmer the further west you go in the North Atlantic and the greatest anomalous waters are way over towards the Davis Straits and off Greenland. This should encourage the blocking high to setup more over Greenland this winter, as well as the summer pattern over the UK itself which is opposite to last year.

Here’s the difference in SST’s between 2009 and this year. The ocean temperature profile is more similar compared to last year but notice the Pacific is colder and the Atlantic is warmer this year that 2009.

October 5, 2009

October 4, 2012

Joe Bastardi said to me back in autumn 2009, where the greatest amount of rainfall is compared to normal during summer but especially autumn, that’s where the cold often goes in winter. Trough in summer means cool, cloudy and rainy. In winter it means cold, snowy and sunny. Remember where that mean trough has been this summer… and remember where that mean ridge was last year and what kind of winter followed… See what I am getting at?

If you’ve questions, please fire away in the comments section. I want you to be able to understand what I am getting at here…

I guess if I am going to do my own version of wishcasting, why do you think I am wanting to see a wet November? It happened in autumns of the past which lead to a long and cold winters to follow.

The reason I keep banging on about this milder autumn and the return of a positive NAO/AO is that if, say we were to have a cold November and early December like we got with the onset of the La Nina in 2010, then the arctic would be drained of cold, it would also mean that we would have a bad start to winter but it would likely end early like it did in 2010-11 or we would likely have a warm mid period before the return of cold. These weak nino’s don’t correlate particularly well with fast start to winter in Northwest Europe. It’s a different story in North America just like autumn’s are, BUT in saying that, their early winter is likely to be coldest further west with the cold pool migrating east through December. Eventually, after a cold front end to winter in the West, it should shut down quick with the replacement of a warm ridge. The cold should then lockidown in the east and southeast by Christmas.

With the weak El Nino, winters tend to be worse from mid to late winter rather than at the start for both the eastern US and UK. La Ninas tend to have a colder front end winter. The pattern simply doesn’t correlate with a fast start to winter. However, I do think we’ll get a taste of cold, perhaps even snow in November within a mild, stormy, Atlantic driven pattern but once we get into December and feedback of those warm North Atlantic waters kick in and the cold has been allowed to build for several weeks over the pole, then look out. December 10 onwards. Much of Britain and the eastern US could be covered in white this Christmas once again.

This month should be the rest in between wet and stormy weather. We got the big rains in September and this should resume late October/November with it’s fair share of hardship. Heavy, flooding rains, storminess and perhaps even a taste of winter on the backside of storm systems should prevail before we enter winter.

NAO can be tough to track in autumn when up and down but it’s trend is negative & that’s important in the long term

The fickle nature of the NAO makes long range forecasts hard to pinpoint short or medium range weather, where exactly systems will go etc. The ensembles are showing opposites every day with one day it showing a strong positive and the next it’s strong negative. This also means daily model runs are often all over the place. In other words if the ensembles showed persistence in the NAO trend and it happened, then there would be more persistency in daily runs to a particular pattern for say the 5-10,10-20 day period.

The thing you can go by as a good guide, is how the index has behaved so far. It’s been mainly negative and so it’s tougher to get it positive.

Here’s what the ensembles are showing today.

It’s interesting how it’s shown to go positive next week and then sharply back to negative by mid-month. That’s plausible given that it did the same in 2009. In that year there was a spike in November which allowed the zonal, ocean driven pattern to dominate both North America and Europe and I do believe we should see 2, perhaps 3 weeks of positive, coupled with the AO which allows the cold to build over the pole. This needs to happen in order for the cold to reload.

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  1. Jamie says:

    Hi Mark.

    Are you motivated by cold winters? I’m a cold winter lover, but a scientist. Apart from last winter, the previous two winters were snowier and colder than anything I’d experienced before i.e. in east Fife… born in 1984. Sure I’d seen deep snow, and cold temperatures, severe blizzards, but the difference to me was that for almost 3 – 4 months combined over 2 winters, the snow did not melt in the east area of Fife which we both lived. For these two winters, I lived at sea level in Kdy, where the snow lay for at least a solid month each winter. I appreciate that these two winters were special. Seeing snow on the beach drove this home to me, having spent my whole life being a keen sea fisherman. These two severe winters, following a colder winter the previous year are an indicator that the current theories of runaway global warming are silly. I understand that your last winter forecast was “wrong” for UK. But it wasn’t so far off. We narrowly missed being “frozen to death for many months.” If this winter, your forecast holds true, it shows that we are in the mini ice age.
    This “winter’s” early frosts have took me by surprise. Several widespread frosts struck Scotland in September, including my near sea abode of Dunfermline. This is not normal relative to the 1990s/ 2000s. I remember many years as a child waiting til December to see a frost. I experienced the – 15 degrees C and 2 to 3 feet of snow in EDINBURGH over the past few years! It was beautiful but caused chaos.

    • Mark Vogan says:

      I love cold winters but WEATHER overall motivates me. If it were just winter, there would be no mark vogan weather for most of the year, lol.

  2. john says:

    Good forecast mark makes a lot of sense, like the way you back up your ideas

  3. Michael says:

    What’s you take on the Scandi-high about 16. October in the latest ECM and the negative AO index? Looks like there could be some rather cold weather for Northwestern Europe down the road this month. Is that in line with your idea for this autumn and winter? And do you still suspect the more or less anti-cyclonic period to end by the end of October/start of November? You mention that the cold over the arctic need to tank and build up, but it seems we will have a cold shot of arctic air first with that negative AO forecasted. What do you think?

    • Mark Vogan says:

      Hi Michael, Yeh I am keeping a close eye on the potential for cold late month and will highlight this probably tomorrow. The NAO looks to bounce briefly positive but by midmonth it could tank. This COULD lead to a decent shot of cold. Snowfall etc, tough to say but a taste of winter can’t be ruled out. I still believe there will be a pull back into November but the way this is going. Anything is possible. If we do see a taste of winter say with low elevation snows, i don’t see it lasting. November should be milder when considering history against this setup globally but a colder pdo/warmer amo, well that can change the eqation.

  4. nick says:

    Surely the weather just doesnt work on patterns? After all if the weather followed patterns then weather forecasting would be so much easier than it actually is?

    • Mark Vogan says:

      No it doesn’t just work on patterns. If it only were that simple. However, by looking at patterns and global patterns, you get a pretty good guide as to what’s going on and what may happen down the road.

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