[Model Output Discussion - Into Winter]

4 minutes ago, Hotspur62 said:

Looks like the cold in Scandi is holding then!

I can imagine the forum now...mmmmm..not really sure about that...those uppers could be to mixed out as they cross the North Sea. Ohh hang on a sec it may be that the air is just to darn dry for snow

[Model Output Discussion - Into Winter]

A broader scale look at the mogreps and we have more support for milder air towards the SW..further North and East and we have greater clustering of colder runs holding on.

So let's just say milder air will attempt to push in next week. The outcome could be a gradual easing off from the cold,but with scope for that cold air to dig in further North and perhaps at times attempt to spread back South again. Now let's just see how much vigour the Atlantic had right now.

More drama than UKTV gold to follow in the run up to Xmas no doubt.

Don't wanna steel Mike's thunder as he does it better than me with the clusters..but blocking is still quite clearly evident amongst them.

Well perhaps more blocking on the few I've posted.

[Model Output Discussion - Into Winter]

Just now, offerman said:

I agree to a point mate but as soon as an Azores high is place it  guides the milder SW’lys to our shores with or without strong atlantic depressions.
Even mod atlantic highs are fairly fluid/mobile the flow and rarely does one sit mid Atlantic at the correct orientation to divert lows over the top with full blasting northerlies containing troughs and sometimes a polar low like days of old.

  

There is speculation over the Hadley cell being more expansive than decades previously..This could explain the more Northern extent of the Azores High. Its definitely a factor we do not want being an hindrance this Winter. So many variables at play...so many things to go against us,but if we catch it correctly then significant cold and wintry conditions still remain a strong possibility.

[Model Output Discussion - Into Winter]

13 minutes ago, offerman said:

Atlantic is just far too strong most years tbh for any longevity of cold on our Island with the exception of Scotlands highlands. 

There's a bit more two it than that mate..we've had long periods over recent times when the Atlantic as been in slumber mode for weeks even months at a time. And if the Atlantic was the sole reason we wouldn't have experienced so many harsh winters of the past.

Personally bar the Azores Heights around iberia looking a little strong to finish the run,I feel that cold air lurks with intent and I'm still not seeing the Atlantic at full steam ahead..its got no know strong TPV to drive it...neither is there deep cold flooding out of Canada to fire it up.

I look forward to the ec ens a little later.

[Model Output Discussion - Into Winter]

6 minutes ago, northwestsnow said:

EXETER update = ukmo 12z,

ie rapid breakdown..

Completely disagree there mate..it states uncertainty about the timing and how far North..its also possibly pushed it back towards mid month with which they say probably milder by this time. But being as there is low confidence on the initial push...makes the next push clouded with uncertainty.

[Model Output Discussion - Into Winter]

1 hour ago, Blessed Weather said:

A Canadian Warming of the stratosphere in January and February 1963 played a big part in making that winter very special. Such warmings don't always have such an impact (some have very little impact) but this type of warming puts pressure on the SPV and can weaken, displace and lead to a full blown SSW.

Source: The Mid-Winter 1963 Stratospheric Warming and Circulation Change

The current warming expected to rumble on for a couple of weeks yet; here's the geopotential height and temperature anomaly at T384 14th Dec from this morning's GFS 06z.

Thanks for that Blessed.

I think we may have the forum doing a check on the hour every hour for the next few weeks on that Canadian warming...now that it's been mentioned as one of the key drivers behind 63.

Some may get that excited the Xmas presents may be opened earlier than expected

OK I'm a tad excited..now let's just have a look at that warming over Canada..think I'm gonna have to give Judah a nudge on this one.

But I definitely feel the momentum will increase as we move further into December.If I'm wrong then so be it..we live and learn..but this year just seems different....yeh we've heard that statement numerous times before but there seems to be much more going on this time around.

Regarding met update it amazes me how you can have reduced confidence in the mid term over inroads of milder air,and the fact it may hold on further North..yet go on to say it will become milder towards mid month with more certainty! I tell you folks its not that straight forward when it comes to moving cold blocks that have been bedded in for weeks! I feel the met are gonna be caught with there trousers down on more than 1 occasion this Winter...pardon the pun.

Food for thought folks...but imagine this...if we did go into a 63 type set up you would still have the met and other pros saying there are now signs of milder Atlantic air moving in! I remember my grandad saying to me years ago this...during 63 everynight they would sit there listening to the world service radio station,and so many times they would say milder air is on the way! Yes forecasting as moved on heaps and bounds since then..but I think you get the general point I'm making here.

[Model Output Discussion - Into Winter]

31 minutes ago, Met4Cast said:

Looks like my expectation for an unsettled start to December is going to come to fruition after all, just with a bonus cold spell before hand. 

Quite a few turn their noses up at background drivers/teleconnections in this thread, I suspect due to a lack of understanding them but I think that’s a shame, they are an incredibly useful tool and add a lot of context to NWP outputs. 

 

The MJO continues it’s progression eastwards is a rather amplified state, this wave has been a little faster than modelled and is expected to reach the central Pacific sometime around mid December, meanwhile we should see overall GLAAM rising via frictional & mountain torque processes thanks to this MJO wave with WWB’s returning. 

i.e I don’t expect we’ll see an Atlantic onslaught for weeks on end, it’s very possible we see a switch to more blocked/colder conditions over the Christmas period > into early January. 

There maybe some that dismiss the drivers as a joke,but I think many on here (me included) are happy to learn about them. You pointed out that Blocking was not possible due to know forcing behind it..but changes on a micro scale altered that logic. Not having a go at you over it as making 100% accurate weather predictions is nigh on impossible.

Sometimes the drivers can fail due to other little nuisances rearing there heads...but they do remain a solid pointer to where we may be heading weeks down the line..But some need to keep in mind that MJO moving into phase 7/8 will not guarantee a cold and blocked outcome...a strong PV in the wrong place can rule this out as we've seen many times before. And keep in mind if the teleconnections are barking up the wrong tree,then NWP is most likely going to be barking up the wrong tree also.

But yeh they are a very important tool and perhaps the few that decide to dismiss them purely refuse too learn by them...or really understand them.

[Model Output Discussion - Into Winter]

I think Nick..aka blue mentioned those eps trending positive for the Atlantic to hit the buffers before it gets chance to get going earlier.

Just had a little study of the 0z ecm ens and as you can see we have good support for more blocking episodes,and plenty which put the strat under constant pressure....and plenty that never have the PV gaining much strength and settling down in the wrong places at all.

From the met today for here...a cold weekend with sharp frosts and risk of snow flurries..what's not to like before we can possibly set ourselves up for a much better event later.

In the meantime enjoy the cold if it's your thing and perhaps keep an eye on any elderly neighbours..Trust me I know that some of them sit in the cold all day as they can't afford the heating! 

[Model Output Discussion - Into Winter]

15 minutes ago, near northampton said:

 What are the overriding factors?

Variables that appear from warmer and colder sections of oceans which seem to be increasing,various degrees of Ice melt...changes in solar activities...larger amounts of emissions through pollutants and volcanic activities which seem to be on the rise. This is probably only a handful of other factors at play here.

[Model Output Discussion - Into Winter]

You know what I'm seriously thinking here folks.

This could be the  Winter when all is said and done that the teleconnections scratch there heads and say what the bloody hell just happened here!

I remember reading somewhere recently back in Summer from a climatological expert that there are so many variables coming into play right now that we are literally entering the unknown!

The moral of this story is do not be that suprised if you wake up some days and see that NWP as completely changed its direction.

The background drivers could well be overuled by overriding factors on occasion.

[Model Output Discussion - Into Winter]

16 minutes ago, Mike Poole said:

It is interesting that while the discussion here has focussed a lot on a return to mild, the ECM 46 has gone the other way today, as you can see from the regimes plot.  The blue +NAO has taken a fair hit today compared to the last two days:

Meanwhile, the 10 hPa zonal winds shows a very weak vortex, the mean touches the climatology 10th percentile (lower red tramline) around the 23rd Dec.

Thanks Mike..those zonal winds have me dribbling like a new born. They are seriously on the decline and that's one hell of a trend.

[Model Output Discussion - Into Winter]

STOP LOOK LISTEN!

Investigate the ecm ens and tell yourself this..

Is this a normal looking NH profile for this time of the year?

Look how many ens have TPV away from Canada and Greenland!

Look how many are still keen to build heights towards the N/NW

And finally I do not think this as been a normal year,and I feel that next year will again be getting us scratch our heads.

This cold snap could have legs...there is not unanimous agreement between all the data to suggest we will be going mild and staying that way!

The plot thickens good folks.

[Model Output Discussion - Into Winter]

We can't discount the cold losing out so quickly just yet...Yes the clustering as trended less cold but we still have colder runs being retained. This out towards day 8... im gonna make a punt here that the block towards the NE is being underrated...im not convinced any milder interlude is gonna be long lived...more drama to follow in the days ahead.

[Model Output Discussion - Into Winter]

I'm not gonna slate that ecm run

Positives we could pull in a Ntly if that Low pushes further East.

2. The pv looks all over the places with even a window of heights around the NE.

3. The azores high as receded from iberia faster than my hairline...far from bad too finish that run.

[Model Output Discussion - Into Winter]

Hey folks...it may seem a crazy solution by GFS..but just remember what the first model to signal this cold snap when others were having none of it was!

[Model Output Discussion - Into Winter]

Just went outside to put the bins out..clear sky and Frost developing...then it hit me...did I over react with my last post by calling it time on this cold snap.

Get back in too see Northern Blocking a PV in separation mode and the model saying...you can stick your background drivers where the sun don't shine.

Let's keep it rolling folks.

[Model Output Discussion - Into Winter]

Impressive cold over the UK to end the week,its a petty we couldn't get more disturbances in the flow though. This cold snap lasts a good week before relenting midweek onwards unless some drastic changes occur in the next few days. The met update although hints at more normal conditions through December,that wintry hazards remain a possibility.

The factors of what goes on with the oceans and over the Arctic during the next couple of weeks.(if favourable) will not come into any model guidance for a good while yet.

So we get a cold snap against the run of play so early in the season! Some may worry that we had a cold snap last December...and look what come next! But do keep in mind we have better signals this time around...yes this does not guarantee anything was this tiny Island...but it puts us in arguably much better shape!

So unless we see a major backtrack from the models over the coming few days....we simply dust ourselves down and go again..Its not the end of the world and I'm sure the chance will come again,and when we are in a better position regarding ssts etc.

Don't get to downhearted over all of this folks..its the weather and will do as she pleases..and like the old UB40 song went...dont worry folks..IVE GOT U BABE!

@claret047 I'm OK thanks..well as well as normal,and im far from a normal kind of normal thanks for asking..bless ya.

That scandy cold pool ain't gonna go down without a fight.

Ps...Massive ECM and we could be back at the races again!

[Model Output Discussion - Into Winter]

Listen here you lot...I've just been to the Dentist as I was in pain..she said its all over for that tooth matty...I said listen here....nothings over till I say its over..you get my drift! OK she looked at me like I had a screw lose...but I never give in and sometimes things can be saved when its against the odds

Those 6z ens show some fruitful possibilities moving further forward...and let me tell you this I'm still learning about teleconnections. And I thank Tams a lot for that as she's answered many of my questions over the last couple of years..but when somebody first mentioned wave breaking too me,I quickly found myself on a Australian surf forum yes I'm still learning  and Tamara is gonna have her work cut out with me one thinks.

In the shorter term we have cold and some snow risk for those around the NE especially..but do watch out for little features cropping up at short notice. Beyond this point it trends less cold but this is not yet 100% nailed down...if we keep that cold block over scandy and a Canadian warming and favourable mjo cycle all come together,we could be looking at much favourable syonotics later next month.

Remember folks the drivers are our friends this year!

[Model Output Discussion - Into Winter]

You know what I love about this forum?

A cold spell as just started and hangs around for at least a week...the morning runs look poor for extending it but the obituaries have already been written for its demise...on the back of model data which is changing more often than money at a  tax office.

This is like a load of family coming round your house one day and saying to your Mother...we are really sorry over the passing of your Huaband,he was such a nice man and looked like he would go on for ages! And ya mom turns round and says....what the bloody hell are you talking about,he's sitting in the living room with his feet up watching Corination Street!

The models can get it wrong...they can get it wrong multiple times a day.

The next week is going to be seasonal with plenty of Frost...let's rejoice with our Xmas shopping when we wipe the ice of our windscreens. Next week could always change for the better.

[Model Output Discussion - Into Winter]

Fantastic 18Z run and just goes to show how blocking once in place can be as difficult to get rid of as the inlaws on Xmas day.

Little heads up from Judah on that Canadian warming.....well its stretched! Stretch something long enough and it weakens and sometimes breaks.

I'm liking all of this and something that sticks in my mind was that a forecaster who worked for noaa for many years said last year that the UK was on the verge of a mother of all Winters! Could have been someone named Rodger not sure now! But the way things are setting up this year my optimism is steadily rising.

[Model Output Discussion - Into Winter]

I've seen enough of the ec 12z ens to say we remain in the game beyond day 7 or 8...theres some crackers amongst them and the PV remains in a confused state.

Thats me signing off as I'm neglecting my caring duties

Time to put ya feet up lads and lasses and blow the froff off a couple

[Model Output Discussion - Into Winter]

Ecm op was somewhat of an outlier. Definitely  a trend to something less cold later but there does remain some spread. Time for things too change again as beyond a week is going some in these type of set ups.

[Model Output Discussion - Into Winter]

This should give you a little lift my friends...what's not to like with the drivers moving forward! 

[Model Output Discussion - Into Winter]

Just to take a more nationwide view of the mogreps ens...We do see more in the way of spread overall...but many areas keep the bulk of the runs towards the colder end of the spectrum. So this very much covers the next 8 days...and in all honesty that's about as far as we can go right now before things become very hazy shall we say!

[Model Output Discussion - Into Winter]

I can't work the Beeb out at times..to compile a forecast and say its bone dry amazes me in this kind of flow. 

2018 Beast from the East and Susan Powell comes on to say yes its gonna be cold..but also very dry!! Bizzare at times.

Ecm..we have some really.cold uppers still in place come 192.

Early thoughts frome me is this could merge into a scandy High!

I'm ready to be shot down.