Model output discussion - 7th January onwards

[WhiteFox]

21 minutes ago, nick sussex said:

All my posts are about the general pattern referring to the UK . And flatter in SW France would inevitably mean flatter for the UK. It would be pretty lonely if I started up a France thread so I haunt this thread instead ! Lol

Unless I clearly mention my location then always take it that any of my moans are just in relation to good or bad re cold synoptics for the UK.

Your next question will probably be why am I bothered over the UK weather when I’m in France . Two things really your weather is a bit more interesting , and I empathize with UK coldies having lived there and suffered so many rubbish winters .

 

Always appreciated Nick. Newbies yet to experience your musings are in for a treat with the upcoming patterns I suspect!

Meanwhile, was looking for a latest MJO, but had trouble finding any other than yesterday. Does anybody know what the CANM is? 

[Mike Poole]

40 minutes ago, swfc said:

Not sure what some members are expecting to see on the mo atm.If your expectations include 09-10 synoptics regarding blocking imo you will be disappointed.slack areas of pressure"wedges"are suffice to direct cold and areas of low pressure favourably for the UK including decent 850s.For me looking at the nhp I don't see major blocking being the big player

Neither do I to be honest, at least not initially, although I think it will be the end result.  What doesn't seem to be on offer is a dry northerly with snow only at the coasts the further south you are, nor does it seem that a cold airflow but with high pressure so close or so strong that hardly any precipitation happens is progged by the models either.  

Trying to keep in mind the whole spectrum of model output without overloading the brain, what is on offer initially seems to be the high risk high reward scenario which may lead to marginal snow events almost anywhere.

As the netweather mantra goes, get the snow in first and the cold will come! 

But I'm convinced that high latitude blocking will be the form horse as we go into February.

Edited January 12, 2019 by Mike Poole

[Nick F]

1 minute ago, WhiteFox said:

Always appreciated Nick. Newbies yet to experience your musings are in for a treat with the upcoming patterns I suspect!

Meanwhile, was looking for a latest MJO, but had trouble finding any other than yesterday. Does anybody know what the CANM is? 

Canadian model?

[Kirkcaldy Weather]

@Skyraker it certainly does seem to have a tendency to develop deep areas of low pressure especially in FI I think it does this even more when it is uncertain probably similar to the current situation 

@WhiteFox it is the CMET: Canadian Meteorology Centre - Ensemble System http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/cmet.shtml 

some from the GEFS legacy 

 

 

[bluearmy]

21 minutes ago, Steve Murr said:

 

As an aside the -10 wasnt an outlier for London on the ECM 00z, infact the spread ( a few days later ) dropped as -14c

Clearly there is opportunity for a frigid easterly to follow the dropping trough .... the evolution of the op is almost totally unsupported looking at the heights and slp at day 10

the dropping discarded vortex segment day 11/12 garners more support 

[bluearmy]

Also, need to keep an eye on the euro troughing .... as referenced quite a bit, this rarely sustains as long as modelled in the longer range .....people have already noticed the changes occurring on the extended gefs and Exeter’s 30 dayer smacks of a lack of Euro troughing suppressed far enough to the south to enable the whole country to stay in the ‘cold enough’ flow without significant incursions - we know the 46 looked ok so must be glosea which is less bullish here ..

Edited January 12, 2019 by bluearmy

[knocker]

1 hour ago, bluearmy said:

Also, need to keep an eye on the euro troughing .... as referenced quite a bit, this rarely sustains as long as modelled in the longer range .....people have already noticed the changes occurring on the extended gefs and Exeter’s 30 dayer smacks of a lack of Euro troughing suppressed far enough to the south to enable the whole country to stay in the ‘cold enough’ flow without significant incursions - we know the 46 looked ok so must be glosea which is less bullish here ..

Just to clarify blue, are you considering the possibility of the positively tilted trough slipping south west and weakening which could suggest various scenarios? The later clusters are not much help at this stage.

Edited January 12, 2019 by knocker

[stodge]

Afternoon all

A degree of concern and despondency among the usual suspects because one OP run doesn't upgrade from the previous.

I thought the 00Z output generally was the best of the winter so far - excellent charts for cold and snow for many - and inevitably the 06Z has not looked quite as good and the worriers have come out.

As a contrast, I really like this chart:

It's barely a week away.

Signs we will see the trough drop SE into NW Europe in about 10-12 days after which we have to hop we get the height rises either to the NE or NW.

One poor OP doesn't make a poor suite and there will be worse charts than this:

 

[damianslaw]

An appropriate time to reiterate that often used message - best stick to the reliable timeframe with the models at the moment - i.e. about 144 hours, and beyond that look at the ensembles for overall theme - but don't become fixated on intra-model runs at the 10 day + timeframe  - conserve your energy! because they are always prone to chop and change.

In the reliable - we are about to see a marked change at long last - after what will have been nearly 4 weeks of high pressure ruling the roost. The change coming about thanks to a shift in the position in the polar front jet - less amplified, but importantly tilting on a NW-SE axis, which allows the high pressure drift far enough westwards to enable a more pronounced atlantic flow to overtop it, with a northerly shot - quite potent on the 17th bringing risk of snow showers to low levels in the north, and low single digit maxima, the first proper wintry hit of the season.

Longer term - the ensembles are showing a significant change, heights building to the north, deep long wave trough anchoring down into europe.

Expect various output from the ECM and GFS in the days ahead for the period 18-24 Jan as they get to grips with the change, it will be messy, no doubt GFS will continue to blow up a barreling low pressure dropping through the UK, it has a propensity to do this, only for the end result to be a much less deep low affair, or none at all, ECM will be less keen on a marked low pressure system, and probably more prone to building heights.

My own view is we are in prime position to see a notably wintry period latter part of January and quite possibly whole of February (oh dear I've said it now), slider lows, trough disruption, sudden small features popping up out of nowhere, in terms of enabling snow, a much better position than a dry northerly or easterly, surprise snowfalls could be the theme.

[A.J]

1 hour ago, tight isobar said:

Decent balanced post.

However-the dynamics between,phasing shout- drop and lock in...once we can resolve the infer...

Im going all out on a stark opening in the large scale...

With pressure punching opening up the pole!!!

And a 'steep' spill-of relaxed troughing..

Falling on ourselves!!..

And ignore the 850hpa signals ...until 72 hrs..

The polar sheild will drop like father xmas on acid!!!

@gift giving

 

 

-example.:

D7321806-58C2-4625-8A39-02271B7958EC.webp

regardless of the current output, and despite how volatile the current output seems to be, ANY post that contains the phrase 'Like father xmas on acid' get's a like and thumbs up from me (and I aint pleased easily).....absolute gem of a post TI ...LOL.....!!

[Singularity]

1 hour ago, bluearmy said:

Also, need to keep an eye on the euro troughing .... as referenced quite a bit, this rarely sustains as long as modelled in the longer range .....people have already noticed the changes occurring on the extended gefs and Exeter’s 30 dayer smacks of a lack of Euro troughing suppressed far enough to the south to enable the whole country to stay in the ‘cold enough’ flow without significant incursions - we know the 46 looked ok so must be glosea which is less bullish here ..

Hmm... there’s a lot of expectation that the MJO will lend a big hand by recycling through P6-P7, enabling HLB to set up, such that if anything the trough should shift further south. Early-mid Feb ought to be the first of the high points for UK freeze potential.

So I figure GloSea5’s not seeing that MJO contribution yet. At least not with strong support. Either that or it cycles it at breakneck speed! Hopefully it’s just a little behind on that; MJO doesn’t seem to be one of its strong points.

As for GEFS, as much as they see the MJO cycle, they also tend to move troughs poleward too readily so... we’ll see, but I’m not convinced.

Edited January 12, 2019 by Singularity
Timing Error

[Ali1977]

ICON isn’t the best start, Jet stream no where near as south.

Really hoping for a big upgrade from the 12zs in the shorter term, chasing FI has gone on too long!! 

Edited January 12, 2019 by Ali1977

[karlos1983]

UKMO 96 looks more promising! Ridging looks better to me

[Ali1977]

1 minute ago, karlos1983 said:

UKMO 96 looks more promising! Ridging looks better to me

Agreed, next frame key though. That spoiler low is, well , a real spoiler 

[karlos1983]

8 minutes ago, Ali1977 said:

Agreed, next frame key though. That spoiler low is, well , a real spoiler 

I’ll take that!!! Good start to the 12z

Edited January 12, 2019 by karlos1983

[SMU]

UKMO 144 very cold across the UK- the low sliding SE like 00z ECM

Shallow blocking to the North alligns the jet axis very sharp across the atlantic

Edited January 12, 2019 by Steve Murr

[Mike Poole]

UKMO at at 144:

Superb!

[SMU]

1 minute ago, Mike Poole said:

UKMO at at 144:

Superb!

Just to add - poss severe frost over Scotland there with cold uppers ( guessing -8c ) & stationary air-

[snowice]

2 minutes ago, Steve Murr said:

UKMO 144 very cold across the UK- the low sliding SE like 00z ECM

Shallow blocking to the North alligns the jet axis very sharp across the atlantic

Can I ask what do you think the 850t would be? 

[Ali1977]

6 minutes ago, Steve Murr said:

UKMO 144 very cold across the UK- the low sliding SE like 00z ECM

Shallow blocking to the North alligns the jet axis very sharp across the atlantic

GFS nothing like it!! 120 here.

[winterof79]

6 minutes ago, snowice said:

Can I ask what do you think the 850t would be? 

 

[SMU]

1 minute ago, snowice said:

Can I ask what do you think the 850t would be? 

-8C Scotland

-6C down the NE coast

-4 to -5c through the middle

-2c in the SW maybe...

Thicknesses for the midlands ~532 DAM

Could be a borderline snow event sinking south

 

[Summer Sun]

5 minutes ago, snowice said:

Can I ask what do you think the 850t would be? 

I can answer that for you right now ranging from -8 in NE Scotland to around 0 further south west

Edited January 12, 2019 by Summer Sun

[mbrothers]

9 minutes ago, prolongedSnowLover said:

It’s now or never if there’s to be any proper cold spell for the majority in the UK. Lack of HLB and heights to the South needs to be reversed ASAP!

Yes it’s the 12th January so a load of nonsense 

[E17boy]

Good afternoon people

Hope you all are well and having a good Saturday afternoon. It's been a cloudy day here in Walthamstow North East London today but temperature seems milder than recent days.

We are 12 days into the new year and our waiting goes on, but is there now some glimmer of a change showing on the horizon. I am firstly so glad that after having this annoying high for weeks it is finally going to give way to a more of a changeable pattern which comes as a big relief. I have been so annoyed with this high pressure and on the face of it a good several weeks of our winter have been spoilt due to this slug.

the change coming is something I was hoping would have come weeks ago but better late than never. This now leads to the big question where are we going to be heading from here. To be to the point (and to take into account I don't take anything more than 5 days away seriously) I would say we don't know what's going to happen. Even at this stage everything is up for grabs. On a positive yes there are signs that the weather is going to get colder and the wintry potential will increase. However to what extent and who will benefit is still to be sorted. 

From my heart I am hoping that the Northery is a starter and as time goes on hoping everything falls into place this norrherly eventually becomes a northeasterly then the main easterly to fix a prolonged cold outbreak. Things will be flipping and changing but I think the next couple of weeks will dictate how this so far boring winter is going to come to wrap up. 

So peeps let's keep our fingers crossed and hope everything falls in place for our island and also for the desire to our hearts. Another thing that will be becoming a concern as time passes is that the days of winter are going past we need something to come to our rescue we are nearly mid Jan and sooner we know it will be Feb time will not be on our side as it is now or has been up to now. It's time to get a bit serious. On a lighter note once again it's a pleasure to read all the posts on here and I am so honoured to always see the regulars posting keep up the good work. We are all in this ride together and my heart says something special will come to us. I can hear the distance horn of the Siberian express maybe this one will be on time.

wishing you all a great evening take care for now heads up and stay safe. 

Our search for our winter wonderland continues 

kind regards