Model Output Discussion - 1st - 7th January

[Grimsby Snow Lover]

Hi

I am a relative newbie and have been looking at the models and just not seeing what other members have been seeing over the last couple of days. All I see is zonal, brief topplers but with a raging jetstream pushing through west to east. Nominal cold for the south and cool/cold more often in the north. Can anyone show me on GFS where the change to cold is happening mid-Jan? Thanks.

The change you are talking about is not guarenteed by any means,however the gfes ensembles are suggesting a change to cooler,more settled weather starting the second week of January, Have a look at these.

http://hw.nwstatic.c...incolnshire.png

http://hw.nwstatic.c...incolnshire.png

Edited January 2, 2012 by Grimsby Snow Lover

[Great Plum]

Hi

I am a relative newbie and have been looking at the models and just not seeing what other members have been seeing over the last couple of days. All I see is zonal, brief topplers but with a raging jetstream pushing through west to east. Nominal cold for the south and cool/cold more often in the north. Can anyone show me on GFS where the change to cold is happening mid-Jan? Thanks.

I can't show using today's 0z GFS as that was a mild outlier in FI...

http://www.netweather.tv/index.cgi?action=charts;type=ens;sess=

Take a peek at the ensembles - they are trending cooler as the run goes on...

Whilst I am no 'expert' by any stretch, I've been on here long enough to know that the models jump around if there is likely to be a pattern change. If you were to compare the 0z GFS from yesterday with today's, they are very different later in the run...

The ECM often picks up an idea, like it did yesterday; then drops it for a bit... Whether it will pick it up again, I don't know.

Remember also that the model runs only go to the middle of January which is when most on here have suspected the 'pattern change' could occur.

As ever, patience is needed!

[Frosty.]

The models this morning are looking serious for northern scotland for blizzards later tonight and tomorrow with up to 20cm + above 100m and with gale to severe gale force easterly winds backing northerly tomorrow, through the central belt of scotland into southern scotland there could be wind gusts of 70-90 mph and generally across the uk it will be wet and very windy for a time before the low shears it's way eastwards dragging colder nwly winds in behind it, more rain midweek and further wintry showers for northern britain on thursday but during friday it looks like a ridge will be pushing east across the uk with some frost but also a fair amount of sunshine, the weekend looks initially settled with frosty nights and sunshine but turning more unsettled with wintry weather in scotland and then becoming settled into next week across the south at least but maybe rather chilly and more unsettled in the far north.

Edited January 2, 2012 by Frosty039

[IDO]

I can't show using today's 0z GFS as that was a mild outlier in FI...

http://www.netweathe...;type=ens;sess=

Take a peek at the ensembles - they are trending cooler as the run goes on...

Whilst I am no 'expert' by any stretch, I've been on here long enough to know that the models jump around if there is likely to be a pattern change. If you were to compare the 0z GFS from yesterday with today's, they are very different later in the run...

The ECM often picks up an idea, like it did yesterday; then drops it for a bit... Whether it will pick it up again, I don't know.

Remember also that the model runs only go to the middle of January which is when most on here have suspected the 'pattern change' could occur.

As ever, patience is needed!

Thanks. Its quite unhelpful that GFS has the op run as a mild outlier >75% of the time (last five days). I just keep thinking they must be onto something; why would you continue to suggest mild when cold is more likely? It is quite disconcerting for their commercial clients and doesn't sit well for their forecasting ability (assuming they are wrong)!

[shedhead]

Hi

I am a relative newbie and have been looking at the models and just not seeing what other members have been seeing over the last couple of days. All I see is zonal, brief topplers but with a raging jetstream pushing through west to east. Nominal cold for the south and cool/cold more often in the north. Can anyone show me on GFS where the change to cold is happening mid-Jan? Thanks.

Tend to agree. Still very much a 'jam tomorrow' look to things across the model suite this morning as far as cold is concerned, but at least all the main players suggest pressure will rise from the south by T+144hrs, ensuring more in the way of dry, settled weather for England and Wales. Whether this high pressure manages to take hold and then perhaps help evolve a colder pattern, or whether it quickly gets flattened once again remains to be seen, but the latter currently looks more likely than the former to me.

Edited January 2, 2012 by shedhead

[lorenzo]

Hi

I am a relative newbie and have been looking at the models and just not seeing what other members have been seeing over the last couple of days. All I see is zonal, brief topplers but with a raging jetstream pushing through west to east. Nominal cold for the south and cool/cold more often in the north. Can anyone show me on GFS where the change to cold is happening mid-Jan? Thanks.

IDO I would suggest this post from Phil earlier in the thread as a good read for where we are now, later in January and also what to keep a look out for on the models.

Remember even each time of model run has it's own particular nuances and when looking for trends keeping track of one set of runs is useful. Day to day try comparing the ECM 12z to begin with as it usually sits top of the verification figures.

ECM this morning shows the PV in a weakened state initially here, compared to tanking away in December.

With continued HP shaping it towards mid month from the North Pacific, in extreme FI on this run also visible a monster Aleutian Ridge.

Looking at the NH pattern let's you see where the main core of influence from the PV will be run on run.

[johnholmes]

Thanks. Its quite unhelpful that GFS has the op run as a mild outlier >75% of the time (last five days). I just keep thinking they must be onto something; why would you continue to suggest mild when cold is more likely? It is quite disconcerting for their commercial clients and doesn't sit well for their forecasting ability (assuming they are wrong)!

I think you are perhaps not really clear on what any commercial clients expect from their forecast sources. Have you spoken to any of them to discover their concerns? All commercial clients receive up to date explanations of how the weather centre they are using use the weather models and what can and what cannot be expected from them. The use of ensemble forecasting allows a client to be given a range of probabilities for wind, weather , temperature etc over various time scales. This is then factored into their commercial requirement and allows hem to plan ahead for that requirement.

Have a look in the Met O web site about commercial clients as one example for a deeper insight into what goes on.

[IDO]

IDO I would suggest this post from Phil earlier in the thread as a good read for where we are now, later in January and also what to keep a look out for on the models.

Remember even each time of model run has it's own particular nuances and when looking for trends keeping track of one set of runs is useful. Day to day try comparing the ECM 12z to begin with as it usually sits top of the verification figures.

ECM this morning shows the PV in a weakened state initially here, compared to tanking away in December.

With continued HP shaping it towards mid month from the North Pacific, in extreme FI on this run also visible a monster Aleutian Ridge.

Looking at the NH pattern let's you see where the main core of influence from the PV will be run on run.

I see what is being said. Changes are afoot to a trend to colder weather (in the NH) but the models will not show consistency until the split of the PV is more defined, ie a higher resolution. The op run from GFS is therefore one of several possibilities and is possibly a default to the current pattern, as this is more sensible at the moment, opposed to modelling a favourable ridge (less confidence). Basically FI at this time is even less reliable than normal.

Just one more thing: I am assuming this change is due to the strat warming splitting the PV? This being the only current synoptics that has a chance of getting us out of this zonal pattern. To me the models have the split in the wrong place (consistently) and even if this has knock on effects downstream, is this enough to override the strong West to East flow? I was looking at the Canadian model (out to 372 as well) and they also try to build heights, but by the end of the run the Atlantic runs over the two attempts and we are back to square one. To me it appears, that although we are in a better position than say, two weeks ago, we are still in the hands of good fortune; there remains a strong probability that the UK will miss out on the better synoptics (from a cold perspective) from this strat warming event. This, may therefore be what the computer models are picking up in the FI output?

[johnholmes]

Perhaps a ray of hope for the cold/snow lovers.

In my very simplistic way of looking at the outer links I use the 30mb temperature. Its almost risen to the average line for the first time in many weeks.

IF it gets above it by, I use, 5-10C, then it, I think, generally shows itself as a cold spell some 15-25 days down the line. Maybe worth watching it, as I say in my simplistic way.

the link is below, but remember the word IF in the sentence above!

http://ds.data.jma.go.jp/tcc/tcc/products/clisys/STRAT/html_e/pole30_n.html

Edited January 2, 2012 by johnholmes

[chionomaniac]

I see what is being said. Changes are afoot to a trend to colder weather (in the NH) but the models will not show consistency until the split of the PV is more defined, ie a higher resolution. The op run from GFS is therefore one of several possibilities and is possibly a default to the current pattern, as this is more sensible at the moment, opposed to modelling a favourable ridge (less confidence). Basically FI at this time is even less reliable than normal.

Just one more thing: I am assuming this change is due to the strat warming splitting the PV? This being the only current synoptics that has a chance of getting us out of this zonal pattern. To me the models have the split in the wrong place (consistently) and even if this has knock on effects downstream, is this enough to override the strong West to East flow? I was looking at the Canadian model (out to 372 as well) and they also try to build heights, but by the end of the run the Atlantic runs over the two attempts and we are back to square one. To me it appears, that although we are in a better position than say, two weeks ago, we are still in the hands of good fortune; there remains a strong probability that the UK will miss out on the better synoptics (from a cold perspective) from this strat warming event. This, may therefore be what the computer models are picking up in the FI output?

When looking at the models in to FI I wouldn't be concerned that it may appear that attempts to build heights may be overrun later by the Atlantic.

The important fact so far is that we are seeing a change with the vortex strength that is allowing blocking to be modelled over the NH. That is probably as much as I will be looking for presently.

[Cloud 10]

Perhaps a ray of hope for the cold/snow lovers.

In my very simplistic way of looking at the outer links I use the 30mb temperature. Its almost risen to the average line for the first time in many weeks.

IF it gets above it by, I use, 5-10C, then it, I think, generally shows itself as a cold spell some 15-25 days down the line. Maybe worth watching it, as I say in my simplistic way.

the link is below, but remember the word IF in the sentence above!

http://ds.data.jma.g...e/pole30_n.html

I wonder if your method might work for the 10mb temps?

http://ds.data.jma.g...f/pole10_nh.gif

[Duane S.]

When looking at the models in to FI I wouldn't be concerned that it may appear that attempts to build heights may be overrun later by the Atlantic.

The important fact so far is that we are seeing a change with the vortex strength that is allowing blocking to be modelled over the NH. That is probably as much as I will be looking for presently.

The point you have made here is so often overlooked. If we had had these charts 4-6 weeks ago prospects would have been a lot grimmer in terms of arriving at a cold scenario but with the recent strat warming and prospects of more throughout the month it seems fairly likely that with the vortex taking a pummeling, northern blocking of some kind is going to be showing up increasingly on the models as they get to grips with it all.

Personally, I think the ECM's 00z evolution (not this morning's, the one before) won't be far off, it was just a bit soon.

[johnholmes]

I wonder if your method might work for the 10mb temps?

http://ds.data.jma.g...f/pole10_nh.gif

Never tried it but its an indication of what appears to be happening as the warming percolates downwards.

I use the 30mb as the indicator for a very rough idea of what is happening.

The suggestion I gave of 15-25 days does have some credability to me (perhaps not to others though) as I have about, I think its, 3 occasions when it has happened. I have none where the warming occurred and it did not turn colder bit its on a VERY VERY limited cross section. Hopefully during this summer I will get on with seeing if there are any real links to what I'm suggesting.

Edited January 2, 2012 by johnholmes

[Duane S.]

I wonder if your method might work for the 10mb temps?

http://ds.data.jma.g...f/pole10_nh.gif

I'd say the 30mb temp is a far better indicator but it's always nice to see the 10mb reaching such dizzy heights as this could in turn work down to the 30mb level.

[Harsh Climate]

Don't look at the gfs 06z, its absolutly dire!!

Hopefully it will be yet another mild outliar

[Frosty.]

I'm amazed there are not more comments about the blizzards being forecast on the models for the northern half of scotland, I am the only person to comment on this rare feature so far this winter, a blizzard which could dump over 20cm of snow with drifting and power cuts to the far north, I guess it's due to the IMBY nature of snow where unless you are going to get it, it's of no interest but the models are really whipping up a storm for tonight and tomorrow with flooding, storm force winds and heavy snow, yet nobody seems bothered!

[IDO]

Nothing of interest or consequence for the next two weeks according to GFS. Its 06z run persists with the current cycle of HP influenced by zonal, but with a milder flow. Uninspiring and arguably the worse run for a long time, bearing in mind the PV split. Any change appears to have been deferred till after mid Jan, possibly due to the Jetstream being revved up by two arms feeding off the US Eastern coast, powering the omnipresent west-east flow for the medium term.

http://nwstatic.co.uk/viewimage.pbx?type=gfs;date=20120102;time=06;ext=384;file=npsjet2;sess=623d95b1d41b945ebec13b0aa054639a;

[Liam J]

Very intense jet being modelled for this week, 350km/h and I magine flights back from the states will be making good time!

[Cal]

Judging by the GFS 0600 hrs run there ain't a lot on offer at the moment from a cold perspective, brief ridges with alternating PM/TM air, fairly dry in the south at times esp in the latter half of the run.

You do wonder if any real pattern change is going to happen a little too late this year, still a long way to go i know, however not a lot in the medium term.

[shedhead]

Well the 06 GFS does suggest SSW in FI, but unfortunately in this case it stands Still Same Weather, indeed if anything it's even milder than the reliable is shaping up. The only straw to clutch from this run is the chance of some frosty night for England/Wales and perhaps some daytime cold where fog lingers, but IF it were to verify the north will again see several double digit days and even the odd double digit night.

I'm sure some will rush to say look at the big picture, it's coming, it's coming!! But then again, so is Xmas!

[mountain shadow]

Well the 06 GFS does suggest SSW in FI, but unfortunately in this case it stands Still Same Weather, indeed if anything it's even milder than the reliable is shaping up. The only straw to clutch from this run is the chance of some frosty night for England/Wales and perhaps some daytime cold where fog lingers, but IF it were to verify the north will again see several double digit days and even the odd double digit night.

I'm sure some will rush to say look at the big picture, it's coming, it's coming!! But then again, so is Xmas!

Indeed, the teleconnection and strat forecasts might be saying something about colder weather on the way but this is most certainly not showing in the model output.

[phil nw.]

When looking at the models in to FI I wouldn't be concerned that it may appear that attempts to build heights may be overrun later by the Atlantic.

The important fact so far is that we are seeing a change with the vortex strength that is allowing blocking to be modelled over the NH. That is probably as much as I will be looking for presently.

Yes that`s the way to look at the output that far ahead.

We can see on different runs how the vortex is being moved about but shown differently run to run.

Bear in mind,-and i have added this caveat to many of my posts recently-,this probable readjustment does not promise an evolution to cold for the UK.,but does improve prospects.

The weakening and fragmenting of low heights over the pole only means a far better chance of high pressure making inroads up there,we still need to be on the cold side of the wavelengths as the cold advects south.

When the possible changes enter the Higher resolution part of the modelling we should start to get a better idea of where the dice will fall for the UK.

The overnight GEFs show the large spread in the low resolution part of the run

http://176.31.229.228/modeles/gens/graphe_ens3.php?x=306&ext=1&y=141&run=0&ville=Londres&runpara=0

The OP trending one of the milder runs in contrast to the Control,which goes very cold.

Edited January 2, 2012 by phil n.warks.

[Osbourne One-Nil]

Well the 06 GFS does suggest SSW in FI, but unfortunately in this case it stands Still Same Weather, indeed if anything it's even milder than the reliable is shaping up. The only straw to clutch from this run is the chance of some frosty night for England/Wales and perhaps some daytime cold where fog lingers, but IF it were to verify the north will again see several double digit days and even the odd double digit night.

I'm sure some will rush to say look at the big picture, it's coming, it's coming!! But then again, so is Xmas!

You know, there's a fine line between being objective and just being consistently contrary for the sake of it. Constantly looking for signals that certain scenarios wont play out doesn't display any more skill than those who manage to eek something positive out of every run. It's the fact that you do it post, after post, after post that gets me, and I suspect, a few others.

[Frosty.]

Nothing of interest or consequence for the next two weeks according to GFS.

Only if you believe every gfs run, yet again there is too much doom and gloom in here yet the bigger picture indicates the pv coming under some strain in the next few weeks. I mentioned about a snowstorm hitting the far north tonight and tomorrow but I may as well have been talking to a wall. The outlook is not set in stone and changes are afoot.

Edited January 2, 2012 by Frosty039

[Harsh Climate]

Tommorows weather is looking very interesting to say the least!

We are going to have a deepening atlantic storm coinciding with a strong jet and heavy perhaps torrential rain, which the convective nature of it may only exacerbate the strong winds! :o .

It first looked like the strongest winds would be in a short window of around between 4am and 8am. Now its looking more prolonged with damaging winds possible from 4am-12 noon, perhaps severe gales lasting into the evening!

I would say gusts widely of 55-65mph, with 80-85mph in more exposed areas!

------------------------------------------------------------------------------------------------------------------------

In this map I have highlighted in red were I expect the highest gusts to be.

In the red box in the west I expect gusts widely of 70-85mph.

In the red box In the east I expect gusts of 70-80mph

And in the black box's I expect gusts of 60-70mph.

Expect:

• Trees/branches down
  
• disuption to travel networks
  
• disruption to power supplies
  
• possible flooding due to the very heavy rain.
  

So be carefull when venturing out

Edited January 2, 2012 by Harsh Climate