Model output discussion - 5th December 2016 - Into Winter we go

[Chris.R]

1 minute ago, Frosty. said:

Good point, I think front loaded MLB winter sums it up bar the occasional unsettled blip.

Yes,  and if the METO were indeed expecting a strengthening PV in December after being disorganised  then that surely would  Signal a blocked start followed by more zonal conditions given time for propagation.  I think the METO have got the bigger picture pretty well so far. 

[Scandinavian High.]

Meto have been bang on they  predicted blocky start to winter we have seen cold down here in the south east we went down to -7 the block was in wrong place for snow meto have done pretty well .

[ArHu3]

52 minutes ago, knocker said:

Not wishing to be pedantic you said this

At that time it was virtually the same as the previous run and you had no idea what was coming later  As it turns out it's just usual variation on a theme with the back end of the run having some wet and windy intervals so very unsettled.

I was on mobile and ECMWF is kind of hard to compare with the previous run because there is always a 12h difference, so you have to compare with the same run from the day before

 

[Seasonality]

Just now, Paul_1978 said:

Sarcasm is the lowest form of wit.

But overall I can't argue with your summary. 

Pot, kettle. And just as a bonus for you that there's no hard feelings I forgot the good old GEM. Still unsettled from the Atlantic for much of the UK but here the Euro block is stronger and further south leading to a snowless Xmas day for much of the continent but frigid surface temps under the high! 

PS... It may happen 

All my fingers crossed all of Europe has the Xmas they want.

[Paul_1978]

7 minutes ago, Summer Sun said:

Well last night the beeb said the deep low to the NW was a low probability looks like they were right

Whilst still unsettled at times in the far northwest we've lost the really deep lows of last night

 

 

Not sure about that Gav - there are some quite meaty looking lows for Christmas Eve on both the GFS and ECM 00z's. 

[MR EXTREMES]

1 hour ago, Iceberg said:

The general trend from the models seem to be predominately boring and average weather temps a little higher than average at times. 

Then from the 22-24th time range a blast of pm air, modelled at its extreme by ecm yesterday but even today's gfs has max temps on the 23rd of 2-4c widely with 5-6c in the far south and sw.  Particularly on 23-24th is the chance of snow showers into the nw. The above is pretty well backed up by ens as well as reasonable cross model agreement. 

At t144 all the models support a similar set up. Ecm, just coming out has a better jet angle with more energy at that time frame. Meto the least. 

Beyond the 23-24 and considerable uncertainty still reigns    As expected at this time range it's unlikely that any models have the actual forecast sorted yet. 

I agree this is far from resolved how many years have we seen blocks removed so quickly and still been firmly in place days beyond the models projection.

winter is far from over.

[marksiwnc]

37 minutes ago, fergieweather said:

very latest seasonal update this week, any such signal is lacking anyway.

Not the news we wanted but we have to accept it.  Hopefully the models may give us some cheer in the new year with cold,crisp and at times the chances of snow country wide... Cheers Ian 

[nick sussex]

Morning all a mixed bag of outputs this morning,  the UKMO  is less than enthused  at T144hrs. It's much more progressive to the north and looks a bit uninterested.

This mornings ECM is an upgrade on yesterday because it now wants to take some energy se but we're still not seeing enough trough disruption. We do need a westwards correction because that could bring some snow into the equation as any rain could meet some colder air heading nw in a se flow.

The GFS is similar to last night but again not enough trough disruption there so its currently a bit close but no cigar. The PV looks to just have a bit too much punch at the moment so I think best to put any battle ground scenario as a low probability .

We'll see how things go during the day.

Edited December 15, 2016 by nick sussex

[Kentish Snowman in Yorks]

So to summarise the model output for Christmas week based on the last 24 hours we have narrowed it down to;

A stormy Northwesterly with a bit of snow on high ground and in Scotland

A raging Southwesterly bringing BBQ temperatures for all

A benign high pressure sitting over the UK

A cold Easterly giving us the chance of some festive cheer

A bit of everything including a Partridge in a Pear Tree

Glad that's sorted then!

My punt will be for a continuation of the drab and mundane nothingness of the last few days.  You can't beat a cloudy drizzly day at 7 degrees to drain away all of your enthusiasm for the upcoming UK Winter!

Edited December 15, 2016 by Kentish Snowman

[knocker]

The ecm ens mean anomaly shows little change portending a quite wet and windy Xmas period with perhaps the SE escaping the worst, Really just a matter of awaiting the evolving detail. Fingers crossed a nasty low isn't thrown up which is always possible with this sort of set up.

Edited December 15, 2016 by knocker

[Devonshire]

7 hours ago, Abyss said:

This Winter was a massive fail in terms of LRF from the Met Office concerning front loaded cold. That is a FACT

Actually - no, it is not  fact (even if you choose to capitalise the word). I may not be a model-interpretation expert but I do have a basic grasp of logic and rhetoric:

1. Since we are nowhere near the halfway mark of winter, you cannot say that we have not had/will not have a 'front-loaded winter' - it may still turn out that way if we get a sudden development of 'proper winter';

2. We may yet get all the way through winter with no more significant frosts 'down south' - in that case, we (southerners) will have had a 'front-loaded winter' (if not a spectacular one);

3. It may turn out that we had a front-loaded winter in terms of blocking patterns over/North of UK offering the *potential* for cold - we may not get these for rest of winter.

I am as disappointed as many that we have not had serious cold/snow yet (well, maybe not as disappointed as many on here!), but lets not trash the LRFs just yet.

Let's wait and see ...

[abruzzi spur]

And, as Ian Fergusson has posted above,  they didn't say it anyway....... 

[Seasonality]

2 minutes ago, Devonshire said:

Actually - no, it is not  fact (even if you choose to capitalise the word). I may not be a model-interpretation expert but I do have a basic grasp of logic and rhetoric:

1. Since we are nowhere near the halfway mark of winter, you cannot say that we have not had/will not have a 'front-loaded winter' - it may still turn out that way if we get a sudden development of 'proper winter';

2. We may yet get all the way through winter with no more significant frosts 'down south' - in that case, we (southerners) will have had a 'front-loaded winter' (if not a spectacular one);

3. It may turn out that we had a front-loaded winter in terms of blocking patterns over/North of UK offering the *potential* for cold - we may not get these for rest of winter.

I am as disappointed as many that we have not had serious cold/snow yet (well, maybe not as disappointed as many on here!), but lets not trash the LRFs just yet.

Let's wait and see ...

Not to mention, and apologies for repeating myself, a LRF is not a guaranteed prediction of the outcome. It was more likely to be colder early on, not guaranteed. If we can predict an event with 80% probability there is still a 1 in 5 chance it will not occur, it is not a fail, just that the less favoured outcome prevailed. What is so difficult for people to understand I wonder?

[Cheshire Freeze]

1 hour ago, abbie123 said:

Meto have been bang on they  predicted blocky start to winter we have seen cold down here in the south east we went down to -7 the block was in wrong place for snow meto have done pretty well .

Aye.... Bang on.... 

[knocker]

Towards the very end of the EPS mean anomalies there are signs of the pattern change and that the EPS is reconsidering it's position A rapid weakening of the vortex lobe over Greenland and associated trough and indication of positive anomalies to the east once more. It may be girding for some retrogression

 

[Matthew.]

I don't think the METO can be wrong anyway because they are only probability forecasts. Just depends where the highs/lows reside, strength of different variables influencing where these will sit. So far is a example how they have sat wrong for cold so far but that can change for the next episodes of blocking to come. Even if a SSW appears it only increases probabilitys of cold, nothing definite. The models looking like bringing a polar westerly flow from next Wednesday ish. They could still backtrack and keep it more settled though.

[TEITS]

I think some have poor memories. I remember many references during late Nov/Early Dec for below average temps and blocking to our NW/N/ This is why I posted in my status update on the 30th November because I couldn't understand why some were making these predictions.

Im not having a dig at anyone personally or organisations like the Met O. However when it comes to seasonal forecast models, technical forecasts based on teleconnections, I personally don't even bother reading them. I make life much easier for myself by just simply following the models to +240.

[fergieweather]

7 minutes ago, knocker said:

Towards the very end of the EPS mean anomalies there are signs of the pattern change and that the EPS is reconsidering it's position A rapid weakening of the vortex lobe over Greenland and associated trough and indication of positive anomalies to the east once more. It may be girding for some retrogression

 

The notion of MSLP rising in Atlantic into Jan, with increased chance of blocking and a shift from SW to E mean flow (with risk of colder periods), remains the UKMO longer range assessment (low confidence of course).

[karyo]

I also don't agree that the Met Office got the pattern right. They predicted below average temperatures for December at the very least but this is not what we are getting.

[swilliam]

12 minutes ago, CreweCold said:

Aye.... Bang on.... 

Which part of that was incorrect - it did turn wetter, there were stronger winds and there was a risk of ice and snow. I imagine the risk was much less than 50% but because it affects more people than other weather events probably thought it was worth mentioning.

[jvenge]

I think I'll need to start posting disclaimers before posting ;-)

GEFS showing quite a lot of divergence after T126, which has worsened the past day or so. Not really sure where things are heading from that point, but for my part of the World there isn't anything overly mild, but also there isn't anything overly snowy as well.

 

[swilliam]

3 minutes ago, karyo said:

I also don't agree that the Met Office got the pattern right. They predicted below average temperatures for December at the very least but this is not what we are getting.

I think you will find that it was a probability of lower temperatures not a prediction.

[Cheshire Freeze]

1 minute ago, swilliam said:

Which part of that was incorrect - it did turn wetter, there were stronger winds and there was a risk of ice and snow. I imagine the risk was much less than 50% but because it affects more people than other weather events probably thought it was worth mentioning.

1st Dec

5th Dec

I think I must have slept through it? 

And if you're being pedantic, you could say that there is a risk at a 2 week lead time of snow and ice in any winter. You've missed the point entirely.

[karyo]

1 minute ago, swilliam said:

I think you will find that it was a probability of lower temperatures not a prediction.

Well then it should have been a probability of above average temperatures which is what we are getting.

[bluearmy]

The blocking certainly continuing the fighback but signs this morning that the week three ec46 picture of low anomoly on a nw/se axis into Iberia may be unlikely to repeat later today with the high euro heights spreading further sw. 

Whilst the higher heights recover themselves to our east, we still await evidence that they will drop to our south.