Winter Model Discussion - Cold Hunting 08/01/13 00z Onwards

[snowking]

From looking at the esembles it looks like the gfs 12z was a cold outliar in the way it keeps the very cold air over the UK between 13th and 21st january.

Most other perpetration's go with what I'm thinking, initial cold airflow around the weekend, becoming less cold (as our high tries to retrogress towards greenland with warmer air riding over it from the north west), with it then becoming cold again. How cold and snowy it will become at that stage is very much in question though.

The only thing you can say in defence of the Op here is that we are talking about a very delicate balance of energy around Greenland at t+96, and that is where the spread starts (not co-incidental that this is the timeframe Steve mentions for your Greenland split flow) - you want the highest resolution modelling possible for this (which is why its so important to have the ECM op on side)

What shows you how good the output is in the longer range at present, is that, given the winter we have had so far, we have a perfectly decent shot at some widespread sleet/snow at the weekend, and yet we are all riding the rollercoaster with every single model run out at +168!

I'm working in a hospital at the moment and took my own pulse earlier...my heart-rate seems unusually raised at the moment....

SK

Edited January 8, 2013 by snowking

[Zenarcher]

Evening everyone about 48 hours ago we had uncertainty between the models and most felt downbeat about them then yesterday we saw a better GFS and UKMO and some of the lesser known models show something good as well, today these models continue to show good charts but the ECM lately was having none of it but this evening it has changed a lot and now we have agreement between the big three.

Next 3 day forecast - Wednesday we see the North of the UK mainly cloudy but dry and the South seeing sunny spells. Thursday Scotland and Northern England will have clear sunshine but Ireland, the rest of England and Wales will be cloudy with rain around which will be heavy at times. Friday showers around Ireland and Southern parts of England but elsewhere cloudy with a chance of sunny spells. Gales over Northern Scotland on Wednesday and gales for South Western Ireland and England on Thursday. Friday a strong but cold breeze from the South East across the UK. Temperatures over the next three days will be colder than what they have been lately and night frosts are likely.

96 Hours Saturday - We have decent model agreement here we have the ECM, UKMO and GFS showing something very similar here the main three and it's so rare to get them all to agree they do get support from the JMA and the Indian model.

So what the models show here is cold temperatures and snow likely as well,

This is from the GFS,

It shows snowfall across Southern and Eastern parts of the UK,

Very cold minimum temperatures as well.

The models this evening do give this support but at 96 hours it's important not to get carried away.

120 Hours Sunday - As expected disagreement starts here but one important thing sticks out between most of the models is they all seem to be keen on bringing in heights up to Greenland. The ECM which is a good run tonight does get good support from another 4 models so that's 5 out of 8 at this point showing a positive agreement. But even those that don't agree are still good in their own right.

As the GFS shows snow still likely with the set up the models agree on,

And once again very low temps,

144 Hours Monday - 6 of the 8 models show heights continuing to rise up to Greenland of course exact details between the models vary at this point but they do show a similar picture which is a positive sign.

As the GFS shows again snowfall across the UK,

Temps still staying very low,

ECM Changes - The big change from this evening's ECM just shows how quickly things can change and how agreement between the models is a important thing remember the ECM yesterday went against most models in the early timeframes and today it has moved over to what most are saying and it does have support much better support than yesterday,

15th of January chart yesterday,

15th of January chart today

Overall - The models were actually good yesterday it's just the ECM that put a downer on things and this morning it showed a flat pattern again but continued to go against most of the other models but this evening it finally agrees. Model agreement is better than what it has been lately the models were struggling to understand the situation a day or two ago but now that they have a better understanding and better agreement in the short timeframe they are starting to show better charts further out. So a positive change in the models tonight but I will say it's very important that people don't get carried away with what they are showing do not get your hopes up yet.

Also don't forget there is a chat room for quick or off topic discussions http://forum.netweather.tv/chat/

[kate1]

well...... do we think Ian Brown feels like a man who fell into a barrel of t*ts and came out sucking his thumb.......?

well...... do we think Ian Brown feels like a man who fell into a barrel of t*ts and came out sucking his thumb.......?

Ohhh... That's a bit mean... I actually think respect is due to him for sticking his head up above the parapet tonight...

[ghrud]

I really feel this will be a short lived cool snap that is being massively overdone by the models & will stick my neck on the line to say there will be very little snow at low levels in England,mainly sleet & mainly dry in Scotland, the easterly's will only last a few days not allowing the really cold air to arrive before a slow breakdown from the west. I know this is not what people want to hear & is defiantly not what I want to be posting on here as I am a massive snow fan. I am no where near as knowledgeable as a lot of people on here but I do tend to have a knack of being right when it comes to forecasting weather. But I am hoping that I will be wrong & really don't mind if I get slated for being wrong providing we get the cold weather everyone is after

Reverse psychology, I like your thinking.

[Paul Sherman]

115 people like this post...most people I've ever seen do this on this forum on 1 post lol!

Yes

That was the post of the winter for me!

Quality from Ian!

[snowblizzard]

It's great to see most of the major models in agreement!

But I think we do have show considerable caution with such a high level (record) of uncertainty.

I'm 57 years old, but looking at some of these charts, I'm as exited as any 5 year old at the prospects!

Edited January 8, 2013 by snowblizzard

[Catacol]

It becomes back to my theory about the NAO refusing to go negative for reasons that need researching in spite of the background signals being otherwise.

We can get cold without the benefit of –NAO but events such as Jan 1987 and Feb 1991 are rare beasts.

I dont understand this statement at all. NAO records are available in tabular format over at CPC, and a 5 sec scan of the last 30 years suggests that your statement here about the NAO is flawed. In 2005 9 out of 12 months had a negative NAO. 3 out of the last 5 Januarys have had a negative and 3 out of the last 5 Decembers the same. There is little or no pattern easily identifiable from the data at all, and the only factor to lend any credence to your statement is that only 1 January from 1998 to 2008 had a negative NAO. In the same period 5 Februarys and 6 Decembers had a negative NAO, however, so I'm not sure that even a poor run of Januarys like that says very much.

What are you trying to say... or is it another attempt to hook a fish or three?

[Snowman.]

I would like to say the CMA has been hinting this for a while starting like this model.

[ANYWEATHER]

Folks . Great Output for Coldies, what more can I say! But Just take a Deep Breath, there may well be some disappointing charts tomorrow. although cold looks fairly certain it could get a little messy from the near perfect output for Wintry weather from the models tonight, but some interesting weather coming up

[IDO]

MOGREPS joins the rest:

EssexWeather

Met Office Ensemble (MOGREPS) showing solid agreement for below average temps and snowfall from this weekend onwards

08/01/2013 20:02

[Bobby]

ECM precip chart for Monday:

Upper air:

The result is lots of snow for Wales and S England. Of course it'll change but nice to see.

[Jupiters Winter]

All the 12Z OP runs look stunning but very likely to be edging towards the colder end with little Ensemble support. Forthcoming OP run Downgrades are very likely with maybe a north westerly component for a few days to become visible on following runs.

[kate1]

Hopefully the 'Shannon entropy' will have diminished somewhat after tonight - would love to hear what Ian F has to say - but am hoping he is far too busy working on severe weather warnings to post on here...

[kate1]

MOGREPS joins the rest:

EssexWeather

Met Office Ensemble (MOGREPS) showing solid agreement for below average temps and snowfall from this weekend onwards

08/01/2013 20:02

That's pretty significant, surely?

[cold snap]

Mods. Any chance of a new thread please I would love to bookmark this before 18zs come out

[keithlucky]

I just phoned Piers..........he said FEET of snow, not inches...FEET

BFTP

LOL

[southbank]

Wonder if "that email" that mat Hugo and IF were tweeting each other was about cross model agreement up to T96

[Moisty]

The BBC South forecast this evening was just mentioning cooler at the weekend but still 8/9 degs and rain sat morning. I suppose they are wary of the uncertainty but the models are now saying otherwise quite strongly, maybe this will change later on. Maybe I should see if Ian F is on duty on BBC West at 10.30!!!!

[Long haul to mild]

Ensembles schmensembles! I've never trusted them and the Op runs are what we need to follow in the 5-6 days period. There are plenty of instances where the Op has followed the ensembles eventually and vice versa. To me, that just shows that they can't be relied upon and we should all stop trying to torture ourselves with the set from the latest GEFS.

The op runs may downgrade a bit (they could hardly get much better!) but IF they have the general pattern anything like correct, then as Nick S said earlier, there is no easy way back to mild.

Fascinating and exciting period coming up!

[TwisterGirl81]

northern Blocking and a shortwave in the southwest approaches around the 18/19th January

It couldn't be could it? lol

http://www.wetterzentrale.de/pics/archive/ra/1881/Rrea00118810119.gif

for newbies who don't get where i'm coming from http://en.wikipedia.org/wiki/Blizzard_of_January_1881

Ok now I understand...would this be around 18 January? And what are the odds?

Thanlyou

[chionomaniac]

Evening Chino,

I am trying to learn about the strat side and its effects with your excellent thread. I am just a bit bamboozled as i thought the potential that we see before us has nothing to do with a warming and the potential effects of a warming would not be felt mid-late January?

I have been at pains to suggest that we can feel the effects of the strat warming sooner than GP, IF and others would suggest. Cohen in this paper - http://web.mit.edu/jlcohen/www/papers/CohenandJones_JC12.pdf suggests in Fig 4 that there are three main increased troposheric height increases following a displaced SSW - at around 5-14 days, 19-25 days and 31-45 days. However this SSW is complicated by the fact that there is also a split - so we may see some variation to these timeframes. Even with that, the effects of height increases with a split vortex are sooner than traditionally suggested - with the strongest seen around days 15-25. All of this fits in with the tropospheric modelling and if you ask me would we be seeing an easterly flow at the weekend without the SSW then my answer would be a resounding no.

[Frosty.]

BBC South showing temps of 8c and rain throughout Saturday. I know that they would not have updated their forecast with regard the latest models but not even a hint of anything colder did they mention! (unlike our Ian in the West who at least alluded to it).

Three words spring to mind...SUDDEN STRATOSPHERIC WARMING, although as GP said recently, the most severe cold is probably 20+ days away so if the gfs/ukmo and ecm are showing these sensational cold charts for this weekend onwards, it boggles the mind to imagine what the weather will be like by the end of the month and during february.

STUNNING 12z CHARTS, best days model viewing since dec 2010 waited patiently and endured the mild weather but payback time is fast approaching, it looks like win win situation with easterlies followed by northeasterlies and northerlies, what could possibly go wrong..

Edited January 8, 2013 by Frosty039

[snowking]

Another tweet to add in, from Chris Fawkes (BBC Forecaster)

EC deterministic runs seems to have most realistic initialisation north Norway, another important area for getting weather details right.

SK

[nick sussex]

The ECM was a fantastic run but the detail will change even if the trend verifies.

The most important thing is that we even have a chance at anything close to that and that will be decided thousands of miles away in the ne USA.

Normally at 120hrs with agreement across the big 3 models you think you could just relax whilst polishing the runners on your sledge but I'd urge people to wait for T96hrs.

This chopping and changing makes me nervous, my head says yes this is the best 3 global models all agreeing at T120hrs and 144hrs on the trend, theres not really a shortwave drama as the one near the UK is modelled within 96hrs to head se this looks solidly agreed on.

I think I'll be viewing the next few runs from behind the sofa! Many of us in here carry the emotional baggage of years of bitter disappointments so perhaps we fall into that it always goes wrong mindset.

My brain says come on don't be ridiculous its not a shortwave just a simple split flow off the ne USA, get a grip for heavens sake!!!

[Panayiotis]

The BBC South forecast this evening was just mentioning cooler at the weekend but still 8/9 degs and rain sat morning. I suppose they are wary of the uncertainty but the models are now saying otherwise quite strongly, maybe this will change later on. Maybe I should see if Ian F is on duty on BBC West at 10.30!!!!

Probably as they change to the 12z at 10.30, so now they are still using the 06z which didnt show the cold and snow for Saturday. Edited January 8, 2013 by Panayiotis