Model Output Discussion - 16th Jan 12z onwards - Smile While You Post!

[Grimsby Snow Lover]

I dont post on here often, but after following this thread the last few weeks Iam puzzled to see the model output struggles to come right on a cold spell, but gets it right on the mild side.

Maybe one day it will get the cold spell spot on ???

I believe it has something to do with our default weather pattern of mainly westerly based wind direction. But fully understand your frustration. The phantom easterly of December 2012 was a typical example of what you have mentioned.

[damianslaw]

No obvious signs from the models today of a return to the pattern we saw early in the month, indeed forecasts are for an amplified flow off the NE USA seaboard and the jet generally on a southerly path aligned NW-SE, yes it looks like we will see a return to more near average temperatures early next week in late January near average is preety cold still.

[bluearmy]

Does anyone know if the Mogreps or EC32 are showing the chance of a Scandy high. None of the GEFS show that evolution.

None of the Canadian ens or gefs show a scandi high at T384. You could just about make a case on one gefs member. The EC ens extended have a less than 10% chance of pressure above 1030mb in that region at day 15.

The short answer is probably 'no', within two to three weeks but it's rare to see a scandi ridge forecast fom two weeks out. They generally pop up unexpectedly.

[bobbydog]

The extended ens still keen on sinking the trough across Europe. Any influence of the Azores ridge held sw but never too far from Iberia re ridging with the upper trough se Europe. Lowest anomoly near n uk. It's likely to be more pm than TM and decent chance that we could see secondary features running into the trough. infact as we head through week 2 perhaps nw Europe could completely under this trough with no chance of TM entry. Whilst the gefs offer decent support to this evolution the Canadian ens maintain euro high anomoly.

No sign of any scandi ridge in the next two weeks at least.

ian seems to think so, maybe he could pop in here and give us his thoughts on how he sees it.

(should add, for anyone reading, that i'm referring to ian simpson, NW forecaster, not ian f.)

[Mark Neal.]

18z GFS take on tomorrows Will it Rain/Sleet/Snow...

4pm.                                            7pm                                              10pm

           

 

1am                                                4am                                          7am        

      

 

Snowfall Acc upto Weds at 1pm.. Less expected than last few runs, but will turn into a nowcast event i'm sure. Slight covering as far south as N london and S Midlands.

(Big pinch of salt)

Edited January 19, 2015 by Mark N

[winterof79]

GEFS sniffing again....they got this cold snap way ahead 

 

The artic high showing its hand on quite a few.Some cold options for early Feb.

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=6&ech=384

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=5&ech=384

Edited January 19, 2015 by winterof79

[Iceaxecrampon]

I dont post on here often, but after following this thread the last few weeks Iam puzzled to see the model output struggles to come right on a cold spell, but gets it right on the mild side.

Maybe one day it will get the cold spell spot on ???

Mild weather = default UK conditions most of the time easier to compute?

Ian

[The Enforcer]

18z GFS take on tomorrows Will it Rain/Sleet/Snow...

Snowfall Acc upto Weds at 1pm.. Less expected than last few runs, but will turn into a nowcast event i'm sure. Slight covering as far south as N london and S Midlands.

1pm.gif

(Big pinch of salt)

A big pinch of salt would be all that is needed to clear any snow if that situation verifies as it races through. Similarly, the big pinch of salt would be sufficient in the UKMO/Euro4 scenario for completely different reasons as precipitation is lacking. It's presently GFS18z & ECM12z & NMM12z  vs  UKMO12z & Euro412z (NMM and Euro4 due to update to 18z variants shortly)

[Trom]

I dont post on here often, but after following this thread the last few weeks Iam puzzled to see the model output struggles to come right on a cold spell, but gets it right on the mild side.

Maybe one day it will get the cold spell spot on ???

Due to the western tracking caused by the earths rotation we will always have a tendency to westerly driven weather and as such it's easier to predict.  Getting the conditions to prevent the westerly Atlantic dominating and therefore cold is a much harder task and prone to much greater uncertainty.  Cold requires a number of elements to fall into place simultaneously and as such is a harder beast to predict and more prone to breaking down as variables change.

Edited January 19, 2015 by Trom

[fergieweather]

GEFS sniffing again....they got this cold snap way ahead

Some similarly colder/more meridional phases also signalled in EC-EPS but crucially, they sit embedded as transient entities in an otherwise strongly mobile pattern, which remains firm in latest EC Monthly (now looking out to mid-Feb), with prevailing story essentially of strong low pressure anomaly to N and scant signal for any high latitude blocking. Now, there is always room for suspicion that a zonal bias may prevail at longer range; nonetheless, the combined cross-model evidence *as it stands* tallies with current thoughts on teleconnectors from UKMO-GGU, who note how:

* current cold phase suspected to be a hybrid result of strong MJO phase 6 and earlier minor sudden stratospheric warming;

* MJO now waning; no further MJO influence expected as a teleconnective player for UK into medium range;

* no or very muted signal for any SSW into medium range, which is interesting, as at odds with typical SSW drivers recently or currently at play (MJO phase 6/easterly QBO/Oct-Nov Eurasian snow cover)

* however, whilst this is recognised as enigmatic, the "significantly reduced" prospect of SSW against average is argued to demonstrate that "...no great significance should be attached to these (above) empirical predictors" (in current situation).

Now, as we all know, pattern change 'surprises' can and do occasionally happen, but we await any *compelling* evidence of such to appear repeatedly and coherently in output. However, for now at least, the above comments summarise the *anticipated* road ahead but I'll try to offer further updates periodically over coming weeks.

Edited January 19, 2015 by fergieweather

[john mac]

Some similarly colder/more meridional phases also signalled in EC-EPS but crucially, they sit embedded as transient entities in an otherwise strongly mobile pattern, which remains firm in latest EC Monthly (now looking out to mid-Feb), with prevailing story essentially of strong low pressure anomaly to N and scant signal for any high latitude blocking. Now, there is always room for suspicion that a zonal bias may prevail at longer range; nonetheless, the combined cross-model evidence *as it stands* tallies with current thoughts on teleconnectors from UKMO-GGU, who note how:

* current cold phase suspected to be a hybrid result of strong MJO phase 6 and earlier minor sudden stratospheric warming;

* MJO influence now waning; no further MJO influence expected as a teleconnective influence for UK into medium range;

* no or very muted signal for any SSW into medium range, which is interesting, as at odds with typical SSW drivers recently or currently at play (MJO phase 6/easterly QBO/Oct-Nov Eurasian snow cover)

* however, whilst this is recognised as enigmatic, the "significantly reduced" prospect of SSW against average is argued to demonstrate that "...no great significance should be attached to these (above) empirical predictors" (in current situation).

Now, as we all know, pattern change 'surprises' can and do occasionally happen, but we await any *compelling* evidence of such to appear repeatedly and coherently in output. However, for now at least, the above comments summarise the *anticipated* road ahead but I'll try to offer further updates periodically over coming weeks.

Ouch!!! That's a bit of a kick between the legs for us coldies and goes against the net weather latest winter forecast. Thanks for the update ian but I hope it's completely wrong!!! Lol Edited January 19, 2015 by john mac

[Bring Back The Beast]

I'm not sure if this can act as a guide to anyone in the uk who is keeping an eye on the first weather front moving in from the Atlantic currently but it looks like the models even as recent as yesterday weren't very accurate with this. Firstly in terms of timing, it was showing the main area of precipitation heading for the East Coast of Ireland by 7pm tonight, it's still moving very slow across Ireland and it hasn't reached the East Coast/Irish Sea yet. Temps and DPs are also a degree or two lower than what was being shown yesterday meaning snow (albeit light) showing up in more areas.

I guess it shows that even in the reliable timeframe that models can struggle. Hopefully it means that areas that may not have been expecting anything might even get a sprinkling.

[bluearmy]

Ian obviously has access to the ec32 clusters but the run is the chilliest I can recall this winter, when viewed from start to finish. For example, Scotland pretty well under sub 530 dam thickness (actual) weeks 3 and 4 and the low anomoly broadly covering nw Europe throughout. lower than average uppers also throughout though no surprise under a mean trough. Remember this is a 51 run mean so that would indicate either some very cold clusters or, more likely, good agreement on the pattern.

I would surmise that, as Ian says, mobile and therefore cold zonal with chances of some thing more notable as features are bound to run into the base or disrupt from time to time.

[fergieweather]

Ian obviously has access to the ec32 clusters but the run is the chilliest I can recall this winter, when viewed from start to finish. For example, Scotland pretty well under sub 530 dam thickness (actual) weeks 3 and 4 and the low anomoly broadly covering nw Europe throughout. lower than average uppers also throughout though no surprise under a mean trough. Remember this is a 51 run mean so that would indicate either some very cold clusters or, more likely, good agreement on the pattern.

I would surmise that, as Ian says, mobile and therefore cold zonal with chances of some thing more notable as features are bound to run into the base or disrupt from time to time.

Absolutely. I don't think those seeking colder conditions need be disheartened. There will inevitably be periods of greater interest.

[Penrith Snow]

Some similarly colder/more meridional phases also signalled in EC-EPS but crucially, they sit embedded as transient entities in an otherwise strongly mobile pattern, which remains firm in latest EC Monthly (now looking out to mid-Feb), with prevailing story essentially of strong low pressure anomaly to N and scant signal for any high latitude blocking. Now, there is always room for suspicion that a zonal bias may prevail at longer range; nonetheless, the combined cross-model evidence *as it stands* tallies with current thoughts on teleconnectors from UKMO-GGU, who note how:

* current cold phase suspected to be a hybrid result of strong MJO phase 6 and earlier minor sudden stratospheric warming;

* MJO now waning; no further MJO influence expected as a teleconnective player for UK into medium range;

* no or very muted signal for any SSW into medium range, which is interesting, as at odds with typical SSW drivers recently or currently at play (MJO phase 6/easterly QBO/Oct-Nov Eurasian snow cover)

* however, whilst this is recognised as enigmatic, the "significantly reduced" prospect of SSW against average is argued to demonstrate that "...no great significance should be attached to these (above) empirical predictors" (in current situation).

Now, as we all know, pattern change 'surprises' can and do occasionally happen, but we await any *compelling* evidence of such to appear repeatedly and coherently in output. However, for now at least, the above comments summarise the *anticipated* road ahead but I'll try to offer further updates periodically over coming weeks.

Thanks Ian,

That excellent summary is worth more than a hundred pages of waffle and hope casting you read on here!

No offence intended to any individual but I think we are all guilty of seeing what we want to see and Ian's 'View from the Bridge' is very welcome.

I have to say the MetO has earned it's funding in the last 12 months with mostly superb short, medium and long range forecasting.

Andy

[Jason M]

GFS has stopped on 240 hours. Maybe its a mercy in light of where the 240 chart is headed.....

 

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=240&mode=0&carte=1

 

Really, about as far away tonight from any northern height rises as its possible to get IMHO.

[Penrith Snow]

Ian obviously has access to the ec32 clusters but the run is the chilliest I can recall this winter, when viewed from start to finish. For example, Scotland pretty well under sub 530 dam thickness (actual) weeks 3 and 4 and the low anomoly broadly covering nw Europe throughout. lower than average uppers also throughout though no surprise under a mean trough. Remember this is a 51 run mean so that would indicate either some very cold clusters or, more likely, good agreement on the pattern.

I would surmise that, as Ian says, mobile and therefore cold zonal with chances of some thing more notable as features are bound to run into the base or disrupt from time to time.

It's also worth noting that any cold zonality will more likely deliver snow to a wider area as we go into February as sea surface temperatures are lower than earlier in the winter, Early March 1995 a classic example.

Andy

[Hotspur62]

Some similarly colder/more meridional phases also signalled in EC-EPS but crucially, they sit embedded as transient entities in an otherwise strongly mobile pattern, which remains firm in latest EC Monthly (now looking out to mid-Feb), with prevailing story essentially of strong low pressure anomaly to N and scant signal for any high latitude blocking. Now, there is always room for suspicion that a zonal bias may prevail at longer range; nonetheless, the combined cross-model evidence *as it stands* tallies with current thoughts on teleconnectors from UKMO-GGU, who note how:

* current cold phase suspected to be a hybrid result of strong MJO phase 6 and earlier minor sudden stratospheric warming;

* MJO now waning; no further MJO influence expected as a teleconnective player for UK into medium range;

* no or very muted signal for any SSW into medium range, which is interesting, as at odds with typical SSW drivers recently or currently at play (MJO phase 6/easterly QBO/Oct-Nov Eurasian snow cover)

* however, whilst this is recognised as enigmatic, the "significantly reduced" prospect of SSW against average is argued to demonstrate that "...no great significance should be attached to these (above) empirical predictors" (in current situation).

Now, as we all know, pattern change 'surprises' can and do occasionally happen, but we await any *compelling* evidence of such to appear repeatedly and coherently in output. However, for now at least, the above comments summarise the *anticipated* road ahead but I'll try to offer further updates periodically over coming weeks.

Oh dear. That doesn't look too promising and as Met Office have been very good so far this winter that is not what most on hear wanted to see.I appreciate things can and do change quickly and hope what Tamara posted last night may hold true in that prospects look encouraging from early Feb onwards from a cold perspective(although to be fair she did state a number of things did need to fall into place for UK to get cold).Bearing in mind how much more data the Met Office have compared to most on this forum and how accurate Met Office have been the clock is well and truly ticking for UK to get what I call a "proper" cold spell.

 

Anyway, lets see how things pan out and hope for UK to have change of fortunes and Met Off to be wrong for once on what they think favoured pattern will be.

[damianslaw]

Oh dear. That doesn't look too promising and as Met Office have been very good so far this winter that is not what most on hear wanted to see.I appreciate things can and do change quickly and hope what Tamara posted last night may hold true in that prospects look encouraging from early Feb onwards from a cold perspective(although to be fair she did state a number of things did need to fall into place for UK to get cold).Bearing in mind how much more data the Met Office have compared to most on this forum and how accurate Met Office have been the clock is well and truly ticking for UK to get what I call a "proper" cold spell.

 

Anyway, lets see how things pan out and hope for UK to have change of fortunes and Met Off to be wrong for once on what they think favoured pattern will be.

 

 

A good post from Fergie there and as he states whilst no likely major freeze on the way or sustained northern blocking, the upcoming outlook is certainly one not without further wintry interest, with some transitional colder interludes with perhaps the UK locked onto the colder side of the jet more often than the milder side - very similar to now. Indeed the Met Office were preety slow off the mark with regard to the current cold spell, many long range forecasts calling for more of the same and it was only about 7 days ahead such forecasts slowly changed.

 

So every chance for further cold wintry episodes ahead - this is turning into a very mixed changeable winter overall with a bit of everything with lots of momentum - with the pause button never being activated.

[TEITS]

Whilst many are are downbeat at Ian F post I would like to remind you of something. For many days (even weeks!) the Met O forecast was suggesting a period of settled weather in the S towards the end of the month.in the 30 day forecast. Now if we look at the output the reverse seems to be true as an unsettled period of weather looks likely.

 

My point is the UKMO do an excellent job but even they will admit that forecasting beyond 14 days is subject to change.

[john mac]

Whilst many are are downbeat at Ian F post I would like to remind you of something. For many days (even weeks!) the Met O forecast was suggesting a period of settled weather in the S towards the end of the month.in the 30 day forecast. Now if we look at the output the reverse seems to be true as an unsettled period of weather looks likely.

My point is the UKMO do an excellent job but even they will admit that forecasting beyond 14 days is subject to change.

Totally agree with you Dave weather can change extremely quickly and I'm thinking wrt Tamara's post yesterday that certain elements are in favour of us it go into a cold spell as we move into feb. May be just a few other things need to go in our favour to complete the jigsaw!! Edited January 19, 2015 by john mac

[TEITS]

If we are to look for the next proper cold spell then this is the period we need to be looking at.

 

http://modeles.meteociel.fr/modeles/gens/runs/2015011918/gensnh-0-1-264.png

 

In my opinion if we are to see a change towards a prolonged, cold spell then the evidence now points towards looking N rather than E.

[Banbury]

I think the control shows nicely what can/could happen, plenty to play for

[Cheese Rice]

EURO4 highlighting great uncertainty for Wednesday snowfall.

12z accumulation

18z accumulation

Always room for a surprise snowfall.

Was no laying snow here a couple of hours ago...

Still snowing now.

[J10]

EURO4 18Hz now out and another outcome.

 

 

This goes more with the North East (n terms of Wales) theme suggested earlier however

 

This also goes with things tuning back to snow over a wider areas later including the south as surface winds revert to an easterly and colder upper air edges in.

 

 

Temps and Dewpoints closely aligned - also very close (initially midnight then 6am)

 

 

You can see why more snow potential in the south later.

 

 

Edited January 19, 2015 by J10