Winter 2017-18: Discussion

server down · 05-11-2017 2:21pm

Oneiric 3 wrote: »

Indeed M.T, but keep in mind that the data I used is not only averaged over the period of 30 years, but also 'smoothed' out over a running period of 7 days, which I did, not only to mark out notable trends in the data, but also to make the graph more palatable to the eye. So the range in the case is not so important (if it can be deemed important to begin with!) as the general trends.

Anecdotally your trend makes sense to me. I rarely remember storms in the early Dec buildup to Christmas, storms just before Christmas and before and over the new year seem common (there are lots of reports of people finding it hard to get back to work in my memory). and then when the kids go back that seems to quiten down again.

Edit: of course that could be the news cycle. A storm on dec 30-jan 2nd is more disruptive of travel than one on jan 12th

sryanbruen · 05-11-2017 3:00pm

Same here ^, only a few storms come to my mind through the early December period. Namely Bawbag in 2011, Desmond in 2015 and North Sea tidal surge in 2013 off the back of my head.

server down · 05-11-2017 3:12pm

sryanbruen wrote: »

Same here ^, only a few storms come to my mind through the early December period. Namely Bawbag in 2011, Desmond in 2015 and North Sea tidal surge in 2013 off the back of my head.

I was going to say 2015/2016 aside. That winter was crazy with storms.

M.T. Cranium · 06-11-2017 6:42am

I would agree, there's a definite lack of major storms (in western Europe) in the first half of December compared to the second half and then the first half of January.

It's not an absolute lack, however, there was a very severe storm around 8-9 Dec of 1886, and if the calendar had changed before 1752, the Daniel Defoe storm (1703) would also have fallen on the 8th of December (it was recorded on the 27th of November because Britain was still using the Julian calendar).

These are not excluded times in other climate regions in the mid-latitudes so it would seem to be a function of the Atlantic circulation. Really cold air masses seem rare across far eastern Canada until well into December so that's probably the main reason why the jet stream remains rather bland, while December is too late in the season to get much stimulation from tropical remnants (some think the Defoe storm might have been a late season tropical remnant, all we know with any certainty about it was that it tracked roughly WSW-ENE across south Wales and central England -- it probably had a nasty backlash effect in Ireland but there are no records that I know of concerning its effects in Ireland).

The pressure pattern that Oneiric3 shows for the recent past could be studied over a hundred and fifty years (almost) by using the wetterzentrale archives. Probably just one pressure reading taken at one location would be sufficient, so I might see if we could form a research communal effort, pick the location and have several people note down daily pressure readings from the maps for that location (Dec/Jan.Feb) then collate it into a study. It sounds daunting but you could probably do one winter in less than an hour.

If I don't manage to get that going, I will see if I have some time this winter to do the data entry from 1871 when the maps begin, to whenever Oneiric's study began, think that was 1981. Then we can see if this effect is permanent or if it shows any tendency to shift with time over 150 years.

If ten people were willing to take ten years and send me the data, we could get this done fairly fast. I could check the work at random to make sure no systematic errors were creeping in.

Oneiric 3 · 06-11-2017 1:25pm

M.T. Cranium wrote: »

I would agree, there's a definite lack of major storms (in western Europe) in the first half of December compared to the second half and then the first half of January.

It's not an absolute lack, however, there was a very severe storm around 8-9 Dec of 1886, and if the calendar had changed before 1752, the Daniel Defoe storm (1703) would also have fallen on the 8th of December (it was recorded on the 27th of November because Britain was still using the Julian calendar).

These are not excluded times in other climate regions in the mid-latitudes so it would seem to be a function of the Atlantic circulation. Really cold air masses seem rare across far eastern Canada until well into December so that's probably the main reason why the jet stream remains rather bland, while December is too late in the season to get much stimulation from tropical remnants (some think the Defoe storm might have been a late season tropical remnant, all we know with any certainty about it was that it tracked roughly WSW-ENE across south Wales and central England -- it probably had a nasty backlash effect in Ireland but there are no records that I know of concerning its effects in Ireland).

The pressure pattern that Oneiric3 shows for the recent past could be studied over a hundred and fifty years (almost) by using the wetterzentrale archives. Probably just one pressure reading taken at one location would be sufficient, so I might see if we could form a research communal effort, pick the location and have several people note down daily pressure readings from the maps for that location (Dec/Jan.Feb) then collate it into a study. It sounds daunting but you could probably do one winter in less than an hour.

If I don't manage to get that going, I will see if I have some time this winter to do the data entry from 1871 when the maps begin, to whenever Oneiric's study began, think that was 1981. Then we can see if this effect is permanent or if it shows any tendency to shift with time over 150 years.

If ten people were willing to take ten years and send me the data, we could get this done fairly fast. I could check the work at random to make sure no systematic errors were creeping in.

The data I used was extracted (about 5 years ago) from the ECMWF reanalysis project via grib extraction (ERA 40 + ERA Interim) and from 5 grid points located at the 5 various locations used in the original 'IMT' series.

http://apps.ecmwf.int/datasets/

The data goes back to 1957 only, and though the ERA - 20 does go back to January 1900, I can't seem extract data from them as I can the other two.

What I will do later, if it is any use, is include all the data from 1957 up to 2010 and average it out as opposed to using just the latest 1981-2010 average.

sryanbruen · 06-11-2017 6:30pm

The AO is expected to go through the floor negative during mid-November :eek:. That kind of AO the GFS ensembles are picking up on at the end here on the chart are 2010 standards negative AO or blocking over the Arctic!

nagdefy · 06-11-2017 6:32pm

sryanbruen wrote: »

The AO is expected to go through the floor negative during mid-November :eek:. That kind of AO the GFS ensembles are picking up on at the end here on the chart are 2010 standards negative AO or blocking over the Arctic!

Nice one! Tis the season to be hopeful!

Send us down the polar vortex, tra la la la la la la la

nagdefy · 06-11-2017 6:52pm

Let's just hope that if any blocking occurs it's not a week or 2 too early. I'd imagine blocking sending down a northerly or northeasterly around mid November may not be as potent as 10 to 14 days later in the season. In 2010 the first wintry 'onslaught' began around the 25th/26th November. We want proper cold to become established in the Arctic regions first. Not to waste a decent setup.

A bit like getting a wonderful easterly in late March which would have been amazing two months earlier.

nagdefy · 06-11-2017 6:56pm

Roughly going by GFS FI projections it looks like they expect sufficient cooling to our north by the 22nd November.

h7nlrp2v0g5u48 · 06-11-2017 7:22pm

droidman123 wrote: »

If you believe anyone can forecast what our weather will be like next January santa Claus must be real too.

I guess your not an avid reader or contributer to this thread because if you were you would not have posted the above.

JCX BXC · 06-11-2017 7:25pm

Valerie Plump Hairdresser wrote: »

I guess your not an avid reader or contributer to this thread because if you were you would not have posted the above.

Normally just pops in around this time of year to make the same comment.

Anyway, I think the opinions are fixed and there's no point in debating furiously over it!

droidman123 · 06-11-2017 7:27pm

Valerie Plump Hairdresser wrote: »

I guess your not an avid reader or contributer to this thread because if you were you would not have posted the above.

I posted the above because its my opinion,all i got was posts having digs,not one person actually discussed What part they didnt agree with.i assume you actually think someone can forecast irelands weather for next january accurately? Of thats your opinion,fine,but my replies wont be sly digs at your post,unlike other posters on here.

h7nlrp2v0g5u48 · 06-11-2017 7:27pm

nagdefy wrote: »

Let's just hope that if any blocking occurs it's not a week or 2 too early. I'd imagine blocking sending down a northerly or northeasterly around mid November may not be as potent as 10 to 14 days later in the season. In 2010 the first wintry 'onslaught' began around the 25th/26th November. We want proper cold to become established in the Arctic regions first. Not to waste a decent setup.

A bit like getting a wonderful easterly in late March which would have been amazing two months earlier.

I would love blocking to take place around the third week of December even if we didn't get too much snow we might get a good hard frost leading up to and including Christmas. Any earlier I feel would make it feel more like Spring.

sryanbruen · 06-11-2017 7:29pm

nagdefy wrote: »

Nice one! Tis the season to be hopeful!

Send us down the polar vortex, tra la la la la la la la

It's all playing very nicely

! Very negative AO, negative NAO, weak La Nina - which I've shown before what that could mean for our Winter, negative PDO, weak solar activity (although not at the favourable part necessarily, it's still good that it's weak), easterly QBO, strong Siberian High.... ah man, it's looking super at this stage for cold. I need to control myself :P before I get myself so excited!

pad199207 · 06-11-2017 7:39pm

sryanbruen wrote: »

It's all playing very nicely ! Very negative AO, negative NAO, weak La Nina - which I've shown before what that could mean for our Winter, negative PDO, weak solar activity (although not at the favourable part necessarily, it's still good that it's weak), easterly QBO, strong Siberian High.... ah man, it's looking super at this stage for cold. I need to control myself :P before I get myself so excited!

A lot of caution still applies though. We were here last November too. No sign of an organised vortex -NAO etc etc and we ended up with bugger all.

Remember the downgrades and spoilers over the past few winters that have nearly put some of us in St Pats!

sryanbruen · 06-11-2017 7:49pm

pad199207 wrote: »

A lot of caution still applies though. We were here last November too. No sign of an organised vortex -NAO etc etc and we ended up with bugger all.

Remember the downgrades and spoilers over the past few winters that have nearly put some of us in St Pats!

Last year had a westerly QBO (positive PDO and a Weak La Nina on its own too without a preceding Weak La Nina to play off from) however which played a HUGE part in the failure of last Winter and the huge inaccuracy of the forecasting. As I explained before in this thread, the QBO in 2016 was very unique and never happened before since QBO records began in 1948. 2015/16 was a westerly QBO Winter. 2016/17 was meant to be an easterly QBO Winter, signs of it beginning to take off happened in April or May 2016 but as we went on into the Summer and then Autumn, the zonal westerlies overtook the easterlies and completely changed the course of the QBO. 2016/17 turned out to be a westerly QBO Winter. I'm no QBO expert, I only picked up on it last Winter due to all the controversy over the unique 2016/17 QBO.

And if it turns out as another disappointment, we will find out why it was. There's almost always a reason why. I say almost because Winter 1997/98 was all in favour of a cold Winter but it never came to fruition. It was a very mild Winter.

EDIT: Wait actually, 1997/98 had a very strong El Nino.

h7nlrp2v0g5u48 · 06-11-2017 7:51pm

droidman123 wrote: »

I posted the above because its my opinion,all i got was posts having digs,not one person actually discussed What part they didnt agree with.i assume you actually think someone can forecast irelands weather for next january accurately? Of thats your opinion,fine,but my replies wont be sly digs at your post,unlike other posters on here.

I know it's your opinion and that you are entiled to post it but i don't have to like or agree with it no more than you have to like or agree with mine. The part of your post I didn't agree with was that MT who posted his long range Winter forecast which may or may not be accurate was dismissed I feel so quickly by your post and as for your other question do i think someone can forecast Ireland's weather for next Janurary I think there is a good chance MT won't be far off the mark even though Janurary is a few months away. Forecasting long range Winter forecast of course can be very difficult but I find MT is not afraid to put his neck on the line and also is not afraid to admit when his predictions do not come to fruition.

droidman123 · 06-11-2017 8:16pm

Valerie Plump Hairdresser wrote: »

I know it's your opinion and that you are entiled to post it but i don't have to like or agree with it no more than you have to like or agree with mine. The part of your post I didn't agree with was that MT who posted his long range Winter forecast which may or may not be accurate was dismissed I feel so quickly by your post and as for your other question do i think someone can forecast Ireland's weather for next Janurary I think there is a good chance MT won't be far off the mark even though Janurary is a few months away. Forecasting long range Winter forecast of course can be very difficult but I find MT is not afraid to put his neck on the line and also is not afraid to admit when his predictions do not come to fruition.

It wasnt my intention to solely ridicule mt,i would "ridicule" ANYONE who thinks they can forecast irelands weather for 3 months ahead.if you read some of the long range forecasts,they are riddled with words "possibly" "mayby" "could be" "might be" this backs up belief.the difference in mt,s scientific methods and the likes of say,james madden or ken ring at the end if the day makes no difference because none of them will be right,unless of course they get lucky

MidMan25 · 06-11-2017 8:27pm

Valerie Plump Hairdresser wrote: »

I know it's your opinion and that you are entiled to post it but i don't have to like or agree with it no more than you have to like or agree with mine. The part of your post I didn't agree with was that MT who posted his long range Winter forecast which may or may not be accurate was dismissed I feel so quickly by your post and as for your other question do i think someone can forecast Ireland's weather for next Janurary I think there is a good chance MT won't be far off the mark even though Janurary is a few months away. Forecasting long range Winter forecast of course can be very difficult but I find MT is not afraid to put his neck on the line and also is not afraid to admit when his predictions do not come to fruition.

What are you basing this expected accuracy on and what has willingness to publish a forecast / admit to failure got to do with anything?

JCX BXC · 06-11-2017 8:30pm

droidman123 wrote: »

I would "ridicule" ANYONE

I'm sorry, but you expect us to have a respectful discussion while you make blatant statements as fact and ridicule anyone who disagrees?

You can't shout about people giving you "sly digs" when you're clearing insulting anyone who doesn't agree with your opinion.

You need to be respectful in order to gain respect, I'm not sure why you think you can come here and post abuse at us and expect us to simply agree!

droidman123 · 06-11-2017 8:53pm

JCX BXC wrote: »

I'm sorry, but you expect us to have a respectful discussion while you make blatant statements as fact and ridicule anyone who disagrees?

You can't shout about people giving you "sly digs" when you're clearing insulting anyone who doesn't agree with your opinion.

You need to be respectful in order to gain respect, I'm not sure why you think you can come here and post abuse at us and expect us to simply agree!

You have completely twisted what i said.i put "ridicule" in inverted commas because the op originally used that word in her post.you just seem full of anger in most of your.posts so i would rather no engage with you,i will gladly discuss my opinions with anyone that can be civil.

Meteorite58 · 06-11-2017 9:22pm

Mod Note: Reminding posters to remain on topic and stop derailing the thread.

Snowbiee21 · 06-11-2017 9:23pm

That gfs 6z summarised in one word amazing !

sryanbruen · 06-11-2017 9:26pm

Snowbiee21 wrote: »

That gfs 6z summarised in one word amazing !

The GFS 12z today is even crazier man, it's far too good to be true, the GFS 12z that is with its 1072mb Greenland block at the end of its run.

nagdefy · 06-11-2017 9:32pm

It's started lads and ladies, hasn't it:) The annual chase and longing for a bit of sneachta! I love it, it's like 7 years of heartache have been cleansed from our souls, hope springs (wrong word winters!) eternal in the human breast! Let the games commence;)

JCX BXC · 06-11-2017 9:34pm

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.

sryanbruen · 06-11-2017 9:37pm

Here's the AO index chart for the latter half of 2010, I'm seeing some similarities to the current outlook.

Clonmel1000 · 06-11-2017 9:45pm

Well I hope we get no snow this winter. Nice mild dry winter will do me just fine and the sooner spring comes the betterðŸ˜‰

MidMan25 · 06-11-2017 9:46pm

Right on cue!

nagdefy · 06-11-2017 9:47pm

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 think you're a wise man!

Winter 2017-18: Discussion

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