Winter 2017-18: Discussion

Gaoth Laidir

A negative AO is no guarantee of cold for us. It could equally mean mild, depending on where the block sets up. I too would be cautious when getting excited over AO charts.

There is very little correlation between our winters and ENSO or the PDO. At our latitude it's the ENSO is more felt in the US, with very little forcing making it this far. Oneiric has done an extensive article on this.

The PDO QBO acts primarily in the tropics and has little effect this far north.

EDIT: I meant QBO, not PDO, so scratch that last point!

Gaoth Laidir

Regarding long-range forecasting, in general the forecasts we see in the tabloids, Madden, Ring, etc. have zero scientific basis and are pure clickbait. I now add theliberal.ie to the list of junk agencies who don't even bother to name the "forecasters" or go into any detail whatsoever.

When it comes to MT, it's different. He has been working on his forecasting system for decades and seems to be streets ahead of anyone else I know when it comes to the types of interactions he goes into in making a forecast. He has shown some skill in the past, more than pure chance, so while I do agree with droidman to an extent, it all depends on what forecast you're talking about. Long range is more about trends, analogies and teleconnections, about which our database and understanding are growing. MT is not saying there will be snow in Carrick-on-Shannon on January 21st, something that Ken Ring will claim is possible (until you challenge him on it and then he says there's something like a ±9 days and 150 miles "cone of uncertainty"). What MT is saying is that from his research, experience and on analogies he sees some signals for increased probabilities of certain largescale patterns developing at approximate times in the future, and these patters favour a certain type of weather. Is he claiming he's certain? Will he still claim he was right if he's not? Is he making any money from this? No to all 3.

By the way, there seems to be an opinion that a forecast can't mention all possibilities at once. That is wrong. You take any winter in the past. Over three months we get all types of weather possible for our location (not all at once). Our "average" climate is the average of a noisy timeseries of peaks and troughs, be it temperature, pressure, precipitation, whatever. I hate the use of the word "Normal", e.g. "it was 2 degrees warmer than "normal". Normal implies that this is what we've always got, a steady state with no fluctuation. Weather is anything but stable, so to have a warm or cold anomaly, be it over a day, week, month or even year, is totally natural, and as long as that anomaly doesn't fall outside 2 or 3 standard deviations then it's not an outlier and can actually be considered a "normal" part of everyday climate.

sryanbruen

Gaoth Laidir wrote: »

A negative AO is no guarantee of cold for us. It could equally mean mild, depending on where the block sets up. I too would be cautious when getting excited over AO charts.

There is very little correlation between our winters and ENSO or the PDO. At our latitude it's the ENSO is more felt in the US, with very little forcing making it this far. Oneiric has done an extensive article on this.

The PDO acts primarily in the tropics and has little effect this far north.

I have gone through this pretty much already, including very strong El Niño events with Oneiric 3 in the Irish Weather Statistics thread.

ENSO does have some correlation though much of it is coincidence, if you look at the bigger picture and or specific events and their specific strengths. As reanalysis charts showed (which I posted earlier in this thread) and the individual Winters in them, Winters with Weak La Niña events that were preceded by Weak La Niña events also tend to be cold Winters. They tend to have strong Siberian ridging with easterlies. Again this is all probably coincidence but it’s interesting nonetheless.

How does the PDO affect the tropics may I ask? I have very little knowledge on it, so you can enlighten me on that please. All I’ve heard is that a negative PDO is better for us compared to a positive PDO for a cold Winter but again like any methodology, there is always odd ones out.

As for negative AO, I never said there was any guarantee of cold. If you pay attention to my early thoughts for Winter 2017/18, I’m not seeing anything particularly cold personally which I was complained to about so I tried to be a little more optimistic. January 2016 had such an example of what you described there. This goes back to my point on saying that a strong Siberian High can be our best friend or our worst enemy depending on where its influence ends up.

JCX BXC

I think Gaoth Laidirs post above in regards to long range forecasting (too long to quote) is an excellently written piece and I think most of us can agree with it. Fully agree myself.

Would Infact like to save it for future reference!

Gaoth Laidir

sryanbruen wrote: »

How does the PDO affect the tropics may I ask? I have very little knowledge on it, so you can enlighten me on that please. All I’ve heard is that a negative PDO is better for us compared to a positive PDO for a cold Winter but again like any methodology, there is always odd ones out.

Sorry, I'm claiming latenight dyslexia! I had the QBO in my head, not the PDO! Of course the PDO has more of an effect, you're right! It's the QBO that's primarily in the tropics.

Time for bed...:rolleyes:

Chisler2

George Sunsnow wrote: »

The alert system isn’t more than a decade old I think

As for snow-coastal low ground Ireland where most people live is probably one of the most hostile environments usually for a snow flake in the world

Except for the East coast of Ireland?  My childhood memories are of frequent Arctic winters.  The white stuff comes straight over from the Russian Steppes.

Lucreto

All those charts are lovely but its still too far out.

I am reading that the Northeast and Mid Atlantic US is going to get it's first Arctic blast this Friday/Saturday.

Nearly every time I see this the Jet stream strengthens and we get storm after storm with mild temperatures.

sryanbruen

Gaoth Laidir wrote: »

Sorry, I'm claiming latenight dyslexia! I had the QBO in my head, not the PDO! Of course the PDO has more of an effect, you're right! It's the QBO that's primarily in the tropics.

Time for bed...:rolleyes:

Lol ok .

derekon

Lucreto wrote: »

All those charts are lovely but its still too far out.

I am reading that the Northeast and Mid Atlantic US is going to get it's first Arctic blast this Friday/Saturday.

Nearly every time I see this the Jet stream strengthens and we get storm after storm with mild temperatures.

Yes Lucreto, definitely one to watch. There is that famous BBC forecast from 1991 where Britain and Ireland were experiencing sub zero temperatures while Richmond, VA in the USA was 22oC in February!! A very cold north east USA not good for Irish cold! A warm NE USA on the other hand....

sryanbruen

derekon wrote: »

Yes Lucreto, definitely one to watch. There is that famous BBC forecast from 1991 where Britain and Ireland were experiencing sub zero temperatures while Richmond, VA in the USA was 22oC in February!! A very cold north east USA not good for Irish cold! A warm NE USA on the other hand....

Sometimes both sides of the Atlantic can be favored for cold though like in 2009/10.

Oneiric 3

sryanbruen wrote: »

Sometimes both sides of the Atlantic can be favored for cold though like in 2009/10.

1962/1963 being another example.

beefburrito

Bring it on..... look's like fantasy island is on the way.....

PokeHerKing

Great cycling weather today, bring on the big freeze!

h7nlrp2v0g5u48

JCX BXC wrote: »

I think I'll keep my optimism at bay for now, it's early November and we're still looking at FI territory.

At least we might have a nice frost. I love a nice frost.

I'll do the same the charts will keep chopping and changing over the Winter months so still too early to say but let's keep the fingers crossed we get over the line this Winter and get one good easterly that will last for about a week giving us plenty of the white stuff.

nagdefy

Most FI, as we all know too well, is eye candy, but there's no harm looking ahead and sometimes weather events are predicted 10 days in advance or so.

If it drives you demented when FI doesn't materialise, best leave the projections alone, if you can roll with the punches of FI and remain sane, no harm in it

sryanbruen

nagdefy wrote: »

Most FI, as we all know too well, is eye candy, but there's no harm looking ahead and sometimes weather events are predicted 10 days in advance or so.

If it drives you demented when FI doesn't materialise, best leave the projections alone, if you can roll with the punches of FI and remain sane, no harm in it

I'm not even rolling with the FI charts or 500mb height anomaly charts in general though, I'm looking at the bigger picture of what's going on around the globe.

Buffalobill29

What's the outlook for winter this year? Snow or no snow?

DOCARCH

Buffalobill29 wrote: »

What's the outlook for winter this year? Snow or no snow?

It will snow somewhere.

nacho libre

It seem the bbc met office online updates are going for cold weather later in November. Of course they have been known to flip before. The only time i remember them being bullish about cold, not using words like there is a risk..., and sticking steadfastly to a cold out look was in early November 2010. M.T Cranium was the same. I long to see the words Greenland express incoming mentioned in one of his forecasts again

sryanbruen

nacho libre wrote: »

It seem the bbc met office online updates are going for cold weather later in November. Of course they have been known to flip before. The only time i remember them being bullish about cold, not using words like there is a risk..., and sticking steadfastly to a cold out look was in early November 2010. M.T Cranium was the same. I long to see the words Greenland express incoming mentioned in one of his forecasts again

I was a bit surprised to their forecast, it's a bit unusual compared to what they usually show.

nacho libre

sryanbruen wrote: »

I was a bit surprised to their forecast, it's a bit unusual compared to what they usually show.

Yes it is. It also begs the question what are they seeing that M.T Cranium isn't. M.T seems to be of the view that any blocking will occur in January.

up for anything

The Met Office told the Daily Mail that there’s a ‘significant possibility’ of colder than normal conditions over the next eight weeks because of a weather phenomenon known as ‘La Nina’.

The opposite of El Nino weather patterns, La Nina curbs mild easterly winds from reaching our shores, while allowing freezing northerly winds to sweep in.

From goodhousekeeping.co.uk

JCX BXC

Mild easterlies?

pauldry

Pacific is getting colder too setting up La Nina

Certainly a good chance we wont have High over Europe Low Pressures to the NW set up all this Winter.

We shall wait and see.

A lot more optimistic about this Winter than the last 6!!!

lapua20grain

Beautiful crisp frosty morning, love this time of the year

KingdomRushed

There's something afoot in the model output from mid November. Lot of blocking trending very strongly. Very interested to see how it pans out. Surely we can't go another year without some real winter weather?

JCX BXC

KingdomRushed wrote: »

There's something afoot in the model output from mid November. Lot of blocking trending very strongly. Very interested to see how it pans out. Surely we can't go another year without some real winter weather?

Many a time have we seen it just disappear, or reach as far as the UK while we have lovely Atlantic drizzle.

sentient_6

I normally quietly follow the winter discussion on here and usually wish for a cold snowy one but I have to say this year im doing a fairly substantial commute by car and really don't want the hassle that comes with it!

Obviously the weather doesn't care for mine or anyone else's opinion one way or another though.

beefburrito

Don't worry, there's enough grit there to cover the whole country.....

carltonleon

beefburrito wrote: »

Don't worry, there's enough grit there to cover the whole country.....

There must be, We've been stockpiling it for the last 6 years