Model output discussion - 7th January onwards

[karlos1983]

1 minute ago, frosty ground said:

That would be the going up part of the roller coaster.

 Actually i think members usually skip that bit...... they just arrive at the top and it's all downhill from there 

[Premiere Neige]

1 hour ago, markw2680 said:

ITS FI FOR A REASON! Did people really expect to come on here this morning to be greeted by the same charts as last night? Really, there will be upgrades and downgrades in every run between now and next week, don’t worry about it let’s get the cold here first before all the panic about a possible easterly 

And it's the same every morning lately then upgrades later in the day. So just wait a few hours

[WhiteFox]

1 hour ago, Leo97t said:

I think that this is a blip, however i think that a deep cold spell can be taken off the table, but it will certainly stay cold. However the last thing we want is for high pressure to return for europe which is looking increasingly likely... 

Which neither the GFS or ECM show. Both models still support troughing into Europe which is the opposite of the high pressure which we saw over the past month. At 240 hours (beyond any sort of reliable timeframe given the uncertainty over exact details), the ECM shows this:

The kink in the isobars to the West of Ireland suggests trough disruption which would prevent high pressure establishing to our South. To further muddy the smaller scale details, there is another storm exiting NE US/Canada, so again amplification would depend on the track of that storm. Given that we still don't know how the energy will phase for the storm forecast for early next week, it is pointless speculating on exactly how any further storms will affect the pattern downstream. For now, the high remains in the mid-Atlantic with ridging attempts. The MJO is forecast to move towards phase 6 by around the 23rd, which is much more conducive to blocking towards the north, so chances should increase after this point.

A further spanner in the works is the handling of the Pacific pattern; yesterday showed a strong push of heights from Alaska towards the Pole. This is much less pronounced today which also suggests that we await further resolution in that area:

 

 

Edited January 16, 2019 by WhiteFox

[weirpig]

dont know why anyone is panicking. Told ya Yesterday Navgem got this. 

Edited January 16, 2019 by weirpig
Trying to check words and Grammar went to school during the Maggie years. sorry

[tight isobar]

11 minutes ago, WhiteFox said:

Which neither the GFS or ECM show. Both models still support troughing into Europe which is the opposite of the high pressure which we saw over the past month. At 240 hours (beyond any sort of reliable timeframe given the uncertainty over exact details), the ECM shows this:

The kink in the isobars to the West of Ireland suggests trough disruption which would prevent high pressure establishing to our South. To further muddy the smaller scale details, there is another storm exiting NE US/Canada, so again amplification would depend on the track of that storm. Given that we still don't know how the energy will phase for the storm forecast for early next week, it is pointless speculating on exactly how any further storms will affect the pattern downstream. For now, the high remains in the mid-Atlantic with ridging attempts. The MJO is forecast to move towards phase 6 by around the 23rd, which is much more conducive to blocking towards the north, so chances should increase after this point.

A further spanner in the works is the handling of the Pacific pattern; yesterday showed a strong push of heights from Alaska towards the Pole. This is much less pronounced today which also suggests that we await further resolution in that area:

 

 

Post of the morning..thus far.

And contains everything-that is....in a nutshell

[Sky Full]

43 minutes ago, helentheroberts said:

It would be really helpful to compare like with like here. I would like to see the 0z charts from yesterday and today compared. 

You might also be interested to see how the models have varied from their forecast of 10 days ago.  Here are the ECM, GFS and GEM from 7th January showing the 17th January, together with their current output for tomorrow:

             +240 hr from 7th January:                            +24hr from now:

ECM      

GFS       

GEM      

It is obvious that they all agree about tomorrow's picture.....  However, not only were they unable to agree with each other 10 days ago, none of the models were able to predict the correct conditions at +240 (with the exception of the ever-present Azores high) even though we have been experiencing generally settled and non-volatile weather over this period.  Surprisingly perhaps, given the flack it generally receives on this forum, the GFS seems to have come closest to getting it right, in my opinion.  This just goes to prove that it is pointless getting excited about 10 day charts because the models are not good enough to pin down the detail.  They're only any good for looking at trends and disappointment awaits anyone who believes that what is showing today for 10 days time is going to verify......

 

[Easton Luna Boys]

2 hours ago, DCee said:

After years of watching models did anyone really expect the ECM not to back track? The GFS is a worthy model and compliments (balances) the ECM very well.

Absolutely, I kept away from here last night as the ramping was verging on hysterical. The golden rule of model watching is always, always wait for cross model alignment at T96 and then cross your fingers as it can still go wrong at that range. Not saying I don't expect to see some swing backs later - I've been around long enough to know how the drama unfolds, but it does seem to be a slow, blending out of any substantial cold as each day progresses, leaving us with a dose of good ol' fashioned PM air bringing its usual, standard wintry mix, so plenty to look forward to for hill walkers and those living in the remote Scottish Highlands.

Seriously though, as I've said before, while I'm not championing any particular model, as a Nescafé blend is always better than Mellow Birds, the GFS is definitely the picked on kid in the playground. It has a tendency to blow up LPs off the eastern seaboard and pump up the AZH for a reason; its modelling of the Northern Hemisphere profile is better than ECM in my view, which year on year can't resist producing HLB scenarios, that rarely come to fruition. 

Caveat; I'm not saying that there won't be further drama (there always is) but the now out of favour) De Bilt aside, the signs look ropey.

Edited January 16, 2019 by Easton Luna Boys

[Jason M]

For 10 days out that is a really good effort by both GFS & ECM. 

[knocker]

18 minutes ago, WhiteFox said:

Which neither the GFS or ECM show. Both models still support troughing into Europe which is the opposite of the high pressure which we saw over the past month. At 240 hours (beyond any sort of reliable timeframe given the uncertainty over exact details), the ECM shows this:

The kink in the isobars to the West of Ireland suggests trough disruption which would prevent high pressure establishing to our South. To further muddy the smaller scale details, there is another storm exiting NE US/Canada, so again amplification would depend on the track of that storm. Given that we still don't know how the energy will phase for the storm forecast for early next week, it is pointless speculating on exactly how any further storms will affect the pattern downstream. For now, the high remains in the mid-Atlantic with ridging attempts. The MJO is forecast to move towards phase 6 by around the 23rd, which is much more conducive to blocking towards the north, so chances should increase after this point.

A further spanner in the works is the handling of the Pacific pattern; yesterday showed a strong push of heights from Alaska towards the Pole. This is much less pronounced today which also suggests that we await further resolution in that area:

 

 

This is still a major player in the ext period as part of the highly amplified upstream ridge/trough complex

 

[Paul_1978]

1 hour ago, Skullzrulerz said:

And this is why you shouldn't ramp one run and overnight it has decided to downgrade

Now hopefully it's just a bilp but to be fair the GFS even though it has been bashed to oblivion...it could be right so I wouldn't discount it 

To be fair as far as ECM goes it was 2 runs. 

[shaky]

Could be a better run this one!!more trough disruption at 114 hours across us and maybe looks a bit better across eastern us!!!more of an easterly flow across the south aswel!

[karlos1983]

3 minutes ago, shaky said:

Could be a better run this one!!more trough disruption at 114 hours across us and maybe looks a bit better across eastern us!!!more of an easterly flow across the south aswel!

It's a bit better upstream, but not enough to stop the pattern flattening on this run

[Methuselah]

Yesterday arvo's charts really got my inner-toddler over-excited; the overnight runs, however, have put the 'gurney old git' back in control. Here's hoping - for some afternoon stonkers!

Plenty of time, yet? 

 

[SteveB]

50 minutes ago, karlos1983 said:

Just out of curiosity, what’s the reaction if the 06z shows blocking akin to ECM from the 12z of yesterday? 

 

Means nothing if it changes again in six hours.

 

If we see consistency over 3-5day's of runs then you could have confidence in the outcome. They only time unfortunately that ever happens is when the models are showing Westerlies.

If it's cold you're after, then consistency goes out of the window. 

[Chris101]

Hey Guys, I dont post too much in here, but i absolutely love this thread and wouldn't be anywhere else in winter.

Im not being funny but over the last few days i've watched the pages and pages of discussion, sometimes heated but generally cool, over the placement and track of an Lp which we now are pretty sure will come down the country NW to SE bringing a forecasters wintry mix nightmare.

So surely we are now in exactly the same position with the next Lp in having no idea till say the weekend whether the ridge and slide if any will go our way.

Cheers Chris

[Man With Beard]

ECM ensembles seeing D10 as a brief milder uptick - upper air mean temperature soon goes back to between minus 5 and minus 6

It's all getting a bit wobbly now - it's all variations around a cold theme, but I'm expecting some minor ups and downs before getting into the "reliable" 

[WhiteFox]

20 minutes ago, knocker said:

This is still a major player in the ext period as part of the highly amplified upstream ridge/trough complex

 

Yes, and indeed the ECM is trending towards that outcome towards the end of the 0z run. 

[Nick F]

2 hours ago, knocker said:

Is to some extent the movement of the intense upper trough in eastern North America a pretty key ingredient? It initiates the amplification of the Bermuda high pressure and it's the direction and strength of the thermal gradient that follows that determines the strength of the ridging which in turn will control the move of surface lows

I used to think that the amplifying and de-amplifying upper troughs and ridges moving around the northern hemisphere are the key ingredient to implications for downstream patterns, but having read numerous US forecasts, partly though interest and also because I go storm chasing there occasionally, there is a lot of reference to how deepening lows over central and eastern the USA, which contain a lot of energy when they interact with gulf of Mexico moisture, can affect the amplitude and shape of upper troughs too, which obviously has implications to wave length and amplitude downstream across the Atlantic. So yes, agree that generally lows tend to follow the 500mb contour, but the lows aren't just purely led by mid-level flow, they are linked in and affect from bottom up to the mid-level flow too, the deeper the low the more N of E the low goes and that can affect the amplitude and shape of the upper trough. This is the issue with the winter storm going along the eastern seaboard next week, deeper it is, the more N of E it will go in track and more likely that the Atlantic ridge may be able to push north towards Greenland - rather than flatter flow of the 00z with the shallower system moving NE.

There is a split stream over the USA, the northern stream digs south in response to Hudson Bay PV dropping south, the northern stream brings south arctic front and interacts with southern stream moisture pulling in from GoM and spawns a low over the Plains of USA later this week, this low then deepens as it moves towards eastern seaboard, uncertainty over whether it will track inland or along coast and how deep. This low then moves NE towards Greenland, it's intensity and track important for low separation around Iceland towards UK next week, as the flow amplifies over the Atlantic downstream of the amplifying east US trough and winter storm. 

Edited January 16, 2019 by Nick F

[ArHu3]

The de Bilt ensemble still looks quite good, haven't seen it this cold and with so little spread in a long time 

[SLEETY]

cma  still going for it 

[weirpig]

Whilst not perfect  a bit of a westward shift on the 6z  

[karlos1983]

2 minutes ago, ArHu3 said:

The de Bilt ensemble still looks quite good, haven't seen it this cold and with so little spread in a long time 

that's yesterday's I'm afraid

Still ok,but not as jaw dropping

Edited January 16, 2019 by karlos1983

[Polar Maritime]

The 6z shows colder air over the continent and a little closer West than the 0z run...

 

[Froze were the Days]

With so many posts every minute (without viewing this thread) I thought the ramping had moved up a notch, how wrong I was!...seems to be a theme when we do get an upgrading on the models in the evening (particularly ecm) the next morning we get downgrades this winter...still interesting model watching but it seems to have been generally like this since November with diddly squat to show, yes somewhat colder weather on the way but not to noteworthy for the foreseeable.

Edited January 16, 2019 by Froze were the Days

[karlos1983]

certainly a better run than the disaster of the 00z

00z v 06z

Edited January 16, 2019 by karlos1983