Winter/Spring 2013 (Model Output Discussion)

icesnowfrost

met eireann are saying mild wet weather right up to the end of next week.........i really dont want to see a repeat of last years mild winter.........maybe the last week in november will be cooler

Capillatus

derekon wrote: »

Another article supporting the theory of a mild winter for Northern Europe with the chances of Greenland blocking thought to be very low.
http://uk.weather.com/partners-winter/mild

Wow. This forecast really "spits" on my statistical outlook that I showed couple of days ago, by saying no Greenland ridging/blocking. Its true that my outlook is quite sensational, but all I want with my statistical "model", is to see if it gets at least the idea right.

If I interpret it as i see it: He is saying wet, windy and mild over Scandinavia and over North Central Europe. What that would mean, is those parts would be under WAA, or Warm Air Advection. That would put those regions under a jet exit region and so meaning a main trough path (looking at Europe) would be from Iceland to UK and then on to North Scandinavia. That would correspond with a positive NAO mode. Of course that is why he also mentions mild winter for E USA and low chance for Greenland blocking. All the arctic air would be packed up in the north, with the exception of E Canada and Siberia/E Asia.



Now if I post my statistical outlook again, its almost a textbook negative NAO. I am not going for the exact same pattern in my "first run", which was made in the end of October, but just to try and get the idea right, based on the state of the oceanic and atmospheric indices, compared to previous falls/winters. And keep in mind that this is a 3-month mean blend, meaning there is some variance from week to week and from month to month. I just find it hard to believe their idea, that there would be no positive geopotential height anomalies up north, given the overall SST anomaly setup. An not to mention an SSW in January.



Lets look at some models.

This is the latest run of the BCC seasonal model.


And this is the Brazilian model, but keep in mind its the October run. Still waiting on the November run. And I am not sure why they have an inverted color scale.


The latest Russian outlook. Even by looking at the temp. and precip. anomaly, its obvious there is a negative NAO pattern behind it.




The Korean model, November run. I had to crop and rotate it, so we can see where Europe is.


This is the CFSv2.


Now what i don't like about it, is its system. Its using an operational system instead of an ensemble system. Meaning, it makes a blend of 40 operational runs. The CFSv1, was using a blend of 40 mean ensemble values. The disadvantage of the operational system is that it has its huge swings from run to run. Its almost like a prolonged GFS.
Here are the last 25 runs for T2m anomaly for December. Its basically allover the place, and we are less then 2 weeks away.



I'm not saying that CFS2 is a bad model. It will eventually get the right idea, but its struggles because of its run to run swings.

Now I have show just a few models. There are some who go with NAO- and some who go with NAO+. Personally I lean more towards a neg. NAO. And I am not trying to "disrespect" the gentleman who made the outlook for The Weather channel. I was only trying to point out why I think its not so likely, despite them being "masters", and for which I respect them.

On a shorter term, an NAO flip is in the works. Also notice how the ensembles are positive biased.






For comparison how we finished fall last year.


Sorry for such a long post, but the name of the topic is "model/technical discussion", so I guess its not a problem?

Best regards.

ZX7R

The latest seasonal forecasts from JAMSTEC is out,it is still going with a colder winter for our region but not as cold as last month.
www.jamstec.go.jp.
Also be care full if your driving this morning roads a very bad with black ice,around the curragh kildare is pretty bad.

Pangea

Interesting look back two years ago near to the day when this forecast was issued by MET UK, quite different from its forecast this week.

Pangea wrote: »

UK Outlook for Monday 22 Nov 2010 to Wednesday 1 Dec 2010:

A generally unsettled and chilly start with clear or sunny spells, but also with showers, particularly in the east, where some longer spells of rain are also possible. Showers wintry over hills. It will soon turn colder into next week with showers turning increasingly wintry to lower levels with a risk of some significant accumulations of snow in northern and eastern parts. Temperatures below average for the time of year with an increasing risk of overnight frost and icy surfaces, especially where skies clear. Feeling cold in the often fresh and mainly northeasterly wind. The cold theme then continues through to the beginning of December, with northern and eastern parts most at risk from wintry weather.

Updated: 1212 on Wed 17 Nov 2010


UK Outlook for Thursday 2 Dec 2010 to Thursday 16 Dec 2010:

It is expected to remain cold across much of the UK, with precipitation amounts around average, or slightly below, throughout the period. Northeasterly winds could bring wintry showers to northern and eastern areas at times. Amounts of sunshine should be above average away from northern and eastern coasts where it is likely to be cloudier. Temperatures are likely to be below average across the country, with frosty nights and the possibility of some wintry precipitation at times for most areas.

http://www.metoffice.gov.uk/weather/uk/uk_forecast_weather.html

UK Outlook for Thursday 22 Nov 2012 to Saturday 1 Dec 2012:
Mostly unsettled for the rest of the week, and into the start of next weekend, with showers and occasional longer spells of rain affecting many parts of the UK, heaviest in the west. Perhaps the best chance of some drier interludes for parts of the east and southeast. Often windy, with the risk of gales in exposed western parts. Generally fairly mild. There is a trend for conditions to become drier for many through the second part of next weekend, with rain becoming largely restricted to the far north and west. Temperatures returning to nearer normal with the risk of overnight frosts. Towards the end of November, there is a good deal of uncertainty, but on balance, colder and drier than average conditions are favoured.

UK Outlook for Sunday 2 Dec 2012 to Sunday 16 Dec 2012:
As is usual, there are uncertainties in the forecast for this period. There are however, some signs of more settled conditions across much of the UK during the first part of December. So, although there are no strong indications of any particular weather type predominating, on balance, colder and drier than average conditions are favoured over the recent mild and damp weather many areas have experienced.

Issued at: 0321 on Sun 18 Nov 2012

Redsunset

Posts deleted like I said they would once thread was becoming derailed from its goal.

BEASTERLY

Capillatus wrote: »

Sorry for such a long post, but the name of the topic is "model/technical discussion", so I guess its not a problem?

Best regards.

By all means, keep the long posts coming. They're a fantastic insight. Decided i'd post these chart in this thread for once, although they do belong in the FI thread(Everything said in this post is based on the hypothetical situation these charts present). Some models, especially the GFS are very keen on a block to our north in the final few days of November and into December with low pressure setting up shop over Europe.

This mornings 6z:


Synoptics such as this are always encouraging, especially so early on in the season. And the GFS has now shown them run after run after run. JMA and GEM showing similar set ups to. The issue with this is the relative warmth of the continent right now(It was a lot colder in 2010), any continental flow we've seen in FI rarely even delivers 850hpa temps of -5C. I feel we need a more northerly source at first, even if it mean us missing out and the continent cooling first.

Another reason for the lack of cold uppers is the positive AO. And it looks set to remain that way, with only a few runs taking it negative. I suspects this is due to the very cold Stratosphere at the moment, down to -80C at the 30hpa level, upper vortex really cranking up. Lets hope to see some warming soon!



We will need this to change to get the cold air displaced to the mid latitudes in large quantities. More of it around the more ways to tap into it!

My ideal scenario, AO goes negative and stays there. The blocking the models are picking up on come to fruition but it gives a set up such as the one below(late FI 6z), then the easterlies come in mid December. Not asking for much.

Tindie

Here the Week Ahead weather
Stormy week ahead
Mild, Wet and Very Windy!
http://www.bbc.co.uk/weather/features/20385951

Sponge Bob

While the NAO has been temporarily positive for around the last week the models are not exactly plunging it into resolutely negative territory over the rest of the month either. Slightly negative going forward would be the kindest description.

davidsr20

weatherfiend wrote: »

What about 2010? where did that one come from?

Very valid point. It's good to be able to compare past and present winters!

average_runner

davidsr20 wrote: »

Very valid point. It's good to be able to compare past and present winters!

2010 was a fluke. won't happen again for along time

Capillatus

I can show you some reanalysis for past winters. Just tell me which winters you want to see/compare.

And when you say winter 2010, do you mean winter 09/10, or 10/11?

davidsr20

derekon wrote: »

Another article supporting the theory of a mild winter for Northern Europe with the chances of Greenland blocking thought to be very low.

Also it notes December should be the coolest month with January and February tending to be both milder and wetter. Total contrast to MT's prediction of a very cold February. I am going with MT on this one!

However there is now a myriad of articles out there, some saying a very cold winter, others saying a mid winter. Don't know what to believe!!

D

http://uk.weather.com/partners-winter/mild

Did I miss something this looks depressing!
Taught we were in for a below average December - jan/feb

derekon

davidsr20 wrote: »

Did I miss something this looks depressing!
Taught we were in for a below average December - jan/feb

My friend, I have learned a few things over the past number of winters:

1. Weather is what it is, not what we want it to be

2. Long range models will inevitably disappoint you. Only trust an indication of very cold conditions once the time frame is around 3-4 days. December 2010 is a perfect example of this

3. Fact Number 1 - Ireland is a small island in the north Atlantic that is usually fully targeted by the jet stream.NOT GOOD FOR SNOW!

4. Fact Number 2 - if the Atlantic ain't cut off during the coming months, the only type of snow in Ireland will be of the wet type that will not last long!

If you bear the above points in mind (particularly not looking beyond 3-4 days for snow), then you won't go far wrong this winter

D

Blizzard 2010

Still think we will have snow at the end of this month. :rolleyes:

weatherfiend

Capillatus wrote: »

I can show you some reanalysis for past winters. Just tell me which winters you want to see/compare.

And when you say winter 2010, do you mean winter 09/10, or 10/11?

I was particularly talking about November/December 2010

Capillatus

Oh. Well, this is how the pattern looked like in December 2010. A really intense pattern, with very, very strong blocking over Greenland and Bering sea. A negative NAO of course. Now if you ask me, I would say that for December 2012, there might be a tendency for a similar pattern. Of course not this strong or extreme, but could be quite similar, given the overall placement of system.

Sponge Bob

This place is very much Ireland on the internet so I'd like to thank you for the modelling input and discussion Capitallatus while apologising for the regular eruptions of Irish XXXXX asking "Wheres's MYYYYY Snow" .

weatherfiend

Capillatus wrote: »

Oh. Well, this is how the pattern looked like in December 2010. A really intense pattern, with very, very strong blocking over Greenland and Bering sea. A negative NAO of course. Now if you ask me, I would say that for December 2012, there might be a tendency for a similar pattern. Of course not this strong or extreme, but could be quite similar, given the overall placement of system.

That was quick, thanks very much!

Capillatus

Sponge Bob wrote: »

This place is very much Ireland on the internet so I'd like to thank you for the modelling input and discussion Capitallatus while apologising for the regular eruptions of Irish XXXXXX asking "Wheres's MYYYYY Snow" .

lol No need for any kind of apologies. (or calling names ) You have to realize, that I came to your forum. So I respect your rules and accept your system. That's how it goes. If I come to visit you in your house, I respect your house rules.
I've been on many forums, and the situation is always the same everywhere, once winters approaches. And of course I understand their enthusiasm, even tho I am personally a bigger fan of spring/summer convective weather, rather than winter.

And its my pleasure to share my weather thoughts with all of you, kind people.

@weatherfiend: You're welcome.

Cheers!

Sponge Bob

Capillatus wrote: »

lol No need for any kind of apologies. (or calling names )

You missed the point. Any forecaster who does not guarantee forecast snow in Ireland this winter (@ less than 50m ASL) will be attacked for being wrong. After the 01 November the weather forum becomes the 'Where is my snow?' forum.

These attackers are all Irish.

Capillatus

Oh i see. Thanks for the heads up.

Well, I guess that's just a big part of this business. What else can I say. I've been through worse I guess.

And I am going to take this opportunity to add some ensemble "visions".

icesnowfrost

average_runner wrote: »

2010 was a fluke. won't happen again for along time

they said that in 2009 :cool:

Capillatus

average_runner wrote: »

2010 was a fluke. won't happen again for along time

^

icesnowfrost wrote: »

they said that in 2009 :cool:

Well, whoever said that in 2009, was wrong (at least regarding December, that is).

December 2009 vs. December 2010. :cool:





Best regards and good night.

Tom Cruises Left Nut

Matt Hugo on Twitter this morning saying the ECM 32 is confident of the blocking pattern taking hold

Also from Matt the anomoly chart:



And the AO:

Tom Cruises Left Nut

One more from Matt on Twitter:

00Z ECMWF clusters are mouthwatering in terms of potential synoptic patterns into early December. Some insane amounts of northern blocking!

https://twitter.com/MattHugo81/status/270451872446431232

Wolfe_IRE

t|nt|n wrote: »

One more from Matt on Twitter:

00Z ECMWF clusters are mouthwatering in terms of potential synoptic patterns into early December. Some insane amounts of northern blocking!

https://twitter.com/MattHugo81/status/270451872446431232

The GFS is now gone the opposite way, although the scandi high is hanging on in there.

Overall, it does look like turning colder by the turn of the month. More settled too. Don't think there is too much if any snow due here on any charts yet.

Ps. I have never heard of Matt Hugo. Just googled him and he works for MetraWeather. Never heard of them either. I presume he knows what he is talking about tntn (i.e. track record?)

Tom Cruises Left Nut

Wolfe_IRE wrote: »

The GFS is now gone the opposite way, although the scandi high is hanging on in there.

Overall, it does look like turning colder by the turn of the month. More settled too. Don't think there is too much if any snow due here on any charts yet.

Ps. I have never heard of Matt Hugo. Just googled him and he works for MetraWeather. Never heard of them either. I presume he knows what he is talking about tntn (i.e. track record?)

Himself and Ian Ferguson who I believe is from the UK Met are always exchanging ideas so I don't think he is just a spoofer anyway !

Blizzard 2010

Wolfe_IRE wrote: »

The GFS is now gone the opposite way, although the scandi high is hanging on in there.

Overall, it does look like turning colder by the turn of the month. More settled too. Don't think there is too much if any snow due here on any charts yet.

Ps. I have never heard of Matt Hugo. Just googled him and he works for MetraWeather. Never heard of them either. I presume he knows what he is talking about tntn (i.e. track record?)

Matt Hugo has a pretty impressive record. Ian Ferguson works for the BBC

Wolfe_IRE

t|nt|n wrote: »

Himself and Ian Ferguson who I believe is from the UK Met are always exchanging ideas so I don't think he is just a spoofer anyway !

Thanks. ECMWF is bringing this at the end of the run


Winds coming from Scandinavia but not very cold by any means. Quite settled though which is good. Looking forward to the 12z run.

ZX7R

After looking at most of the different model runs ,there defiantly looking like there will be a blocking ridge to the north west of Ireland during the start of December could bring us north, north east winds cold air ,worth watching to see what happens could be a bit of snow if the cold air from north mixes with air from south
I could be wrong with my reading of the models whats other peoples views