WINTER WEATHER 2013/2014 - See Mod Note First Post

dexter647

dopolahpec wrote: »

ECM has suddenly thrown up the suggestion of heights migrating north to Greenland at t216. Very nice chart. Looking forward to tomorrow's run now.

The good old pub run continuing on with this theme far out in fantasy island land,but it's been hinted at for a few runs now so maybe just maybe...Lets hope it continues because by jebus has this been one hell of a boring spell of weather

derekon

Some of you folks may already be following a thread over on the NW boards (link below) that gives a regular update on Stratospheric warming (which is a strong precursor to any blocking high).

In summary, nothing of note to date and of course any warming noted is not felt for up to 6 weeks later lower down in the atmosphere (our area of interest for wintry weather).

So I would not be getting my hopes up for anything snowy anytime soon. Update below:

Post from NetWeather
In summary no change tonight still in the foreseeable - 10 day - range. NW to N incursions probable due to ongoing meridionality upstream, but until there is a change in stratospheric temperatures helping to slow down those zonal wind speeds any high pressure that starts to build north will be quickly flattened. The hoped for warming over Canada has not materialised in November, something that would have helped build our greenland high.


http://forum.netweather.tv/topic/78508-model-output-discussion-18th-nov2013-12z-onwards/page-85

konman

dopolahpec wrote: »

ECM has suddenly thrown up the suggestion of heights migrating north to Greenland at t216. Very nice chart. Looking forward to tomorrow's run now.

Just had a look at a few of the other models running out to 240h and there seems to my untrained eyes a theme there, open to be corrected though.

Rebelbrowser

can't remember the specifics but werent the strat warming based forecasts last winter all wrong? i think they suggested a Jan cold spell that never happened?

rickdangerouss

konman wrote: »

Just had a look at a few of the other models running out to 240h and there seems to my untrained eyes a theme there, open to be corrected though.

Looks to be that things are changing, to what, I would see the repeat of a week or two ago. Wet, cold and windy. Early winter spell of weather.

Rebelbrowser wrote: »

can't remember the specifics but werent the strat warming based forecasts last winter all wrong? i think they suggested a Jan cold spell that never happened?

SSW events, help create abnormal hights, they do this apart of a team. If I recall, one was expected, turned out the cold spell went to another part of the world.

dopolahpec

Nice charts this morning. Particularly ECM. cold northerly. Widespread snow possibilities

pistolpetes11

Rebelbrowser wrote: »

can't remember the specifics but werent the strat warming based forecasts last winter all wrong? i think they suggested a Jan cold spell that never happened?

Yep and there was one , whilst it enhances our chances of a cold shot its not the be all and end all ,

Strat warming disrupts or splits the Polar Vortex , we then need the resulting disruptions/ split to go favourably for us , should it head over Canada for instance this is bad for us .

Redsunset is our Resident expert here on the Strat and usually has a thread up on and running on it .

Larbre34

dopolahpec wrote: »

Nice charts this morning. Particularly ECM. cold northerly. Widespread snow possibilities

To what timescale?

Villain

Way out in Fantasy Island and anything that is shown is short lived, nothing to get excited about yet, just enjoy the nice dry weather our High Pressure is giving us.

maquiladora

The idea of a cold snap/cold spell for early Decemeber has been hinted at on the models for several days now. I think it will probably happen. Like the last one, it will probably end up being a watered down and short lived version of whats on the models now : a couple of days of polar maritime/arctic air. There is no sign of any proper blocking on the cards with the stratosphere not looking co-operative.

We'll see what happens but I wouldn't expect too much.

patneve2

pistolpetes11 wrote: »

Yep and there was one , whilst it enhances our chances of a cold shot its not the be all and end all ,

Strat warming disrupts or splits the Polar Vortex , we then need the resulting disruptions/ split to go favourably for us , should it head over Canada for instance this is bad for us .

Redsunset is our Resident expert here on the Strat and usually has a thread up on and running on it .

Very true! If I remember correctly Dec 2010 wasn't caused by strat warming. However, Feb 2009 and March 2013 were.

pistolpetes11

Larbre34 wrote: »

To what timescale?

2-4 days , closer to 2 !

Iancar29

pistolpetes11 wrote: »

2-4 days , closer to 2 !

Pardon myselfs , but why aint we keeping the talk of anything around the 6th , 7th in the FI thread ?

People complain that we hype things up when we put thoughts in here...

for example , GFS op is an cold outlier compared to its ensembles.

pistolpetes11

Iancar29 wrote: »

Pardon myselfs , but why aint we keeping the talk of anything around the 6th , 7th in the FI thread ?

People complain that we hype things up when we put thoughts in here...

for example , GFS op is an cold outlier compared to its ensembles.

This thread is only really chatting about what may happen through out the winter , charts and discussion about them are mainly in the FI thread ,

If this little glimpse of winter comes into a reliable time frame it can have its only little thread

pistolpetes11

A lad can only dream

Perfection/

hatrickpatrick

So this'll sound appallingly immature, but does anyone else find they have immense double standards when it comes to FI charts? When I see ones which give hope I'm like "It's definitely a possibility, hang in there, sure how inaccurate could it be? Damn you naysayers!" but when I see disastrous ones I'm like "Bah, it's FI, what kind of eejit would actually believe this sh!te"

Hooter23

UK Met Office going for a colder than average winter

http://www.metoffice.gov.uk/media/pdf/s/c/A3_plots-temp-DJF.pdf


TEMPERATURE:
Indications are that December will most likely be colder than average. For December-January-February as a whole uncertainty is quite large but below-average temperatures are more likely than above-average.
Overall, the probability that the UK-mean temperature for December-January-February will fall into the coldest category is between 20 and 25% and the probability that it will fall into the warmest category is between 10 and 15% (the 1981-2010 probability for each of these categories is 20%).

MiNdGaM3

Update for the December and January 12z CFS trends. (explanation for the charts can be found here http://www.boards.ie/vbulletin/showpost.php?p=87038570&postcount=290)

The 12z CFS data for the 23rd doesn't seem to be available, but it shouldn't matter too much.

Below is the latest December chart, the daily values in the blue bars, 10 day mean in red and trend in black.



The last 7 days have averaged 1.4 (between weak and moderate blocking to the north), with 5 runs showing positive sea level pressure anomalies, 1 showing negative and showing neutral. (the previous 7 days were exactly the same).
It would appear that, despite a downward trend over the whole chart, we've seen the forecast northern blocking increase since the end of October, from weak to moderate levels of blocking. The CFS is then currently hinting a moderate level of blocking to our north in December.

Below is the chart for January


The last 7 days have averaged 1.3, with 5 runs showing positive anomalies, 1 negative and 1 neutral (the previous 7 days were 2.7, with 5 positive, 1 negative and 1 neutral).
The 10 day mean for January has remained remarkably consistent rarely moves far from the moderate blocking category. In the last 65 runs, 74% have suggested +ve SLP anomalies to our north in January.


Here are some highlighted charts from the last while

The best
November 13th 12z CFS for January 2014


The worst
November 26th 12z CFS for January 2014

Elmer Blooker

maquiladora wrote: »

The idea of a cold snap/cold spell for early Decemeber has been hinted at on the models for several days now. I think it will probably happen. Like the last one, it will probably end up being a watered down and short lived version of whats on the models now : a couple of days of polar maritime/arctic air. There is no sign of any proper blocking on the cards with the stratosphere not looking co-operative.

We'll see what happens but I wouldn't expect too much.

A toppler? http://www.wetterzentrale.de/pics/archive/ra/1962/Rrea00119621212.gif and two days later
http://www.wetterzentrale.de/pics/archive/ra/1962/Rrea00119621214.gif
There has been a lot of comparisons with 1962 this year?

Weathering

@Hooters O dear lord no. The last time they released a seasonal FC was for a BBQ Summer and we know how that panned out ha.

Great input @ mind

rickdangerouss

Big increase in snow cover for Russia and Canada\North USA.

SSW are nice to have working on winters side, sometimes the job can get done if NAO\AO are in neutral\negative











The link below has alot of related links for reading up on SSW

http://p-martineau.com/stratospheric-sudden-warming-references/

Hooter23

Weathering wrote: »

@Hooters O dear lord no. The last time they released a seasonal FC was for a BBQ Summer and we know how that panned out ha.

Great input @ mind

Ya I know I thought they stopped doing long range forecasts I dont believe any of them anyway think we dont have the technology and all the information to correctly predict seasons most of the time with so many forecasts of course someone will be right:cool:

nacho libre

patneve2 wrote: »

Very true! If I remember correctly Dec 2010 wasn't caused by strat warming. However, Feb 2009 and March 2013 were.

i think chino' over on netweather mentioned that it was in fact caused by a strat warm, but it was quite an unusual setup, it's over my head to understand what he meant by that exactly.

MiNdGaM3

nacho libre wrote: »

i think chino' over on netweather mentioned that it was in fact caused by a strat warm, but it was quite an unusual setup, it's over my head to understand what he meant by that exactly.

In December 2010 I believe the polar vortex was more disorganised than usual as the stratosphere remained relatively warm due to a number of minor disruptions, rather than any large warming event.

rickdangerouss

nacho libre wrote: »

i think chino' over on netweather mentioned that it was in fact caused by a strat warm, but it was quite an unusual setup, it's over my head to understand what he meant by that exactly.

Netweather has for a great intro in to SSW

http://www.netweather.tv/index.cgi?action=stratosphere-tutorial;sess=

http://forum.netweather.tv/topic/71340-stratosphere-temperature-watch-20112012/#entry2148930

Found the SSW discussion for DEC 2010.

http://forum.netweather.tv/topic/64621-stratosphere-temperature-watch/page-10

I will let you all read it and not ruin the surprise.

Example of the thinking for the time.

All is not lost.
It`s still feasable to get decent cold from a Scandi/Siberian block provided there`s enough meridonality in the jet and sufficient energy underneath such a block.
I must say though these have been rare beasts in recent times and it does require the strongest part of the Vortex towards the other side of the pole and the jet to play ball.(not much to ask for!).

Clonmel1000

It was 10 degrees today...just saying like

rickdangerouss

Netweather has put up a winter forecast.

http://www.netweather.tv/index.cgi?action=winter-forecast-in-depth;sess=

Has a SSW forecast attached too.

nacho libre

Conclusion
So overall we will see a traditional old-fashioned winter. It starts drier, with a moderate southerly-displaced jet stream and a building westward moving Siberian High as winter progresses. There will be periods when the UK is situated south of the polar front jet and the risk of snow will increase, but also times when milder conditions will ensue before the Scandinavian high builds. The main uncertainty will be whether colder conditions will take hold as winter progresses, but my feeling is that this will occur as the increased meridional patterns that we have witnessed over the last five years are likely to act as a trigger for stratospheric warming.


i hope for mike65's sake he is right:P

dopolahpec

GFS is cold in FI. 0Z ECM has the northerly but I see a risk of an eastward shift on both. Even just so far that the UK get this and not us. Overall very interesting charts.

maquiladora

dopolahpec wrote: »

GFS is cold in FI. 0Z ECM has the northerly but I see a risk of an eastward shift on both. Even just so far that the UK get this and not us. Overall very interesting charts.

The past two GFS op runs have been very much on the colder side, if not the coldest of all the ensembles, so I'd take those FI charts with an even bigger pinch of salt than usual.