General Model Output Discussion

[bluearmy]

i havent looked closely at the ens sypnotics but it would nt surprise me if the uppers dont look too cold away from this transient cold pool around the 20th. the mixing of lower uppers into the block doesnt seem to be a strong call amongst the ens at the moment. however, a continental feed with uppers around -3c isnt to be sniffed at. without a decent upper cold pool, we will struggle to get too much snow without a shortwave attack from the sw. i wouldnt bank on that cold pool for a while yet - it could easily miss us or may not even exist once we get to next week.

[kold weather]

I'm not so sure why everyone thinks a cold medium to long term outlook is nailed on as such?! Some of the south east and southerly winds projected on a few of the models are coming from a long way south and even given they are heading over a cold continent there is a lot of warmth in the SE Med at the moment!

I also suspect the Atlantic isn't going to go back in its box without a struggle. The models are struggling. Just because they currently favour a cold future doesn't mean this state of affairs has changed chaps!!

The reason why there is actually a decent amount of confidence is simply because as long as we get a cut-off low then a colder set-up will occur, the only uncertainty is whether the high gets far enough north to allow a pure easterly flow in. Therefore with only one real variable there can probably be higher then normal confidence in the broad evolution.

As for the SE airflow, trust me at this time of the year with snowcovered Europe, that WILL be cold, besides models are sourcing the air from E.Europe rather then the SE Europe, and this area has been frigid for quite some time now, plus its flowing over a cooling North Sea.

Finally with regards to the Atlantic, your probably right in at least the medium term it won't just shut down but thats good for us, because as long as we get under the block then I strongly suspect given the position of the PV and what is progged to be occuring in the Stratosphere we could well see an attempted attack from the SW followed by the PV slowly weakening.

[grab my graupel]

Can we get back to discussing the Models please, folks?

Thank you

[swilliam]

I don't know which model or sum of models the MetO are using for their long term outlook but they are not seeing much cold - just colder than average (although I guess that could mean anything from rather could to extreme cold)

'During the first part of the week there will be one or two wintry showers here and there, although most places will be dry with colder than average temperatures, icy stretches and areas of mist and freezing fog. Then later in the week it currently looks likely that a mixture of rain, sleet and snow will encroach from the southwest, with less cold conditions edging into western and northwestern areas. Then over the weekend and during the second week we are currently expecting a gradual transition to nearer normal temperatures across all areas as a southerly or southwesterly airflow becomes established across the United Kingdom. There will be rain, sleet and hill snow at times, although confidence on the timing of this transition to milder weather is currently only low.

They are then going with what is shown on the GEFS control run rather than the OP

Edited January 13, 2010 by swilliam

[Duane S.]

It now looks fairly nailed on that there will be a pretty massive Siberian/Scandi block. Whether or not WE can tap into it is a completely different kettle of fish though. I think that what is also very likely is that there will soon be a massive amount of cold air that will be displaced out of the Arctic.

The MJO seems to heading in the right direction to support blocking up there and the AO is showing signs of heading back to a fairly deep nagative state again in about a weeks time.

What I would say is that the scenario I have arrowed can be the catalyst.

[ANYWEATHER]

I don't know which model or sum of models the MetO are using for their long term outlook but they are not seeing much cold - just colder than average (although I guess that could mean anything from rather could to extreme cold)

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They do acknowledge that this is an experimental forecast and if you read it everyday it does vary greatly.! Two things from that forecast comes to me, they do say it will get colder than average from next week and do mention too that confidence is very low to as and when the weather becomes mild. It is a very vague forecast at the best of times, notice they use rain sleet and snow so really they cover themselves from all angles!

Edited January 13, 2010 by ANYWEATHER

[Guest North Sea Snow Convection]

I don't know which model or sum of models the MetO are using for their long term outlook but they are not seeing much cold - just colder than average (although I guess that could mean anything from rather could to extreme cold)

'During the first part of the week there will be one or two wintry showers here and there, although most places will be dry with colder than average temperatures, icy stretches and areas of mist and freezing fog. Then later in the week it currently looks likely that a mixture of rain, sleet and snow will encroach from the southwest, with less cold conditions edging into western and northwestern areas. Then over the weekend and during the second week we are currently expecting a gradual transition to nearer normal temperatures across all areas as a southerly or southwesterly airflow becomes established across the United Kingdom. There will be rain, sleet and hill snow at times, although confidence on the timing of this transition to milder weather is currently only low.

They are then going with what is shown on the GEFS control run rather than the OP

That METO update doesn't really support any significant upper cold pool from the east arriving as suggested by the operational modelling as a possibility from mid week. Just shows I think, that as TWS said earlier, it is best not to get carried away and assume that another cold easterly reload is a definite to see out January

I still don't think that any current warming or MMW potential is going to necessarily cement the sustaining of cold weather. If there are going to be any effects from that then they are unlikely for a few weeks yet.

So it is quite possible that we will still have to go through an atlantic sequence as a backlog of positive zonal winds are piped through. The METO update ahead does reflect that possibility in terms of their expectation of atlantic influence finally returning eventually. Clearly though the gradual transition suggestion means that the block is going to be very stubborn, much as we already know!

So with all that said, the outlook for the next week or so is below average to cold and plenty of time of course for the easterly suggestion to keep gaining momentum.

Edited January 13, 2010 by North Sea Snow Convection

[nick sussex]

I don't know which model or sum of models the MetO are using for their long term outlook but they are not seeing much cold - just colder than average (although I guess that could mean anything from rather could to extreme cold)

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They do acknowledge that this is an experimental forecast and if you read it everyday it does vary greatly.! Two things from that forecast comes to me, they do say it will get colder than average from next week and do mention too that confidence is very low to as and when the weather becomes mild. It is a very vague forecast at the best of times, notice they use rain sleet and snow so really they cover themselves from all angles!

Those forecasts are subject to as many changes as the models so I always take them with a pinch of salt. Theres always a tendency in here for people to get too concerned about a breakdown rather than concentrating on the nearer term. If we get the easterly it's likely to last longer than the gefs ensembles suggest as theres a tendency by the models to break down blocking patterns prematurely.

I'm much more intetested in pre 144hrs as the gfs although alone on this could deliver more snow for certain parts of the UK. Considering what the operational runs were showing a few days back we've now seen a trend to bring in yet more colder and wintry weather.

[igloo]

starting to get good agreement for next weeks weather by looking at todays model outputs one model in particular for the past few days has been showing very similar runs and yes you might not agree but the GEM model has been very good lately

[billy]

That METO update doesn't really support any significant upper cold pool from the east arriving as suggested by the operational modelling as a possibility from mid week. Just shows I think, that as TWS said earlier, it is best not to get carried away and assume that another cold easterly reload is a definite to see out January

I still don't think that any current warming or MMW potential is going to necessarily cement the sustaining of cold weather. If there are going to be any effects from that then they are unlikely for a few weeks yet.

So it is quite possible that we will still have to go through an atlantic sequence as a backlog of positive zonal winds are piped through. The METO update ahead does reflect that possibility in terms of their expectation of atlantic influence finally returning eventually. Clearly though the gradual transition suggestion means that the block is going to be very stubborn, much as we already know!

So with all that said, the outlook for the next week or so is below average to cold and plenty of time of course for the easterly suggestion to keep gaining momentum.

Hi Tamara, I dont think we should worry too much about the met office 6-15 day outlook . Lets not forget it was only the 27 November when they updated their winter forecast and said it was most likely to be a mild winter. Just three weeks later we were in our first cold spell . I know they are fairly accurate up to about 3/4 days out , but I dont think they are as good as some of the experienced guys on here at longer range. Maybe they rely too heavily on computer predictions instead of like some on here who look for trends that may occur that the models are yet to pick up on. Of course they may turn out to be right with the latest 6-15 day forecast. As ever time will tell. Regards Billy

[Thundery wintry showers]

Looking over the last few Met Office updates, it seems they expect some sort of short-lived easterly with some wintry showers for eastern areas, followed by a change to warmer, unsettled weather from the SW. So in essence the cold wins temporarily but then the mild pushes through as we head towards February. They've been pretty consistent with that over the last few days, and haven't backed down when the models have suggested the continental air never quite reaching us at all.

Whether they'll be right or not is open to question, but I don't think their 6-15 day track record has been too bad this winter.

Odds are now perhaps 70-30 in favour of some kind of easterly outbreak- as opposed to 30-70 against yesterday- but there is still a chance that we could end up in a mild cloudy no-man's land, and also that any easterly might turn out to last just a couple of days.

[kold weather]

I still don't think that any current warming or MMW potential is going to necessarily cement the sustaining of cold weather. If there are going to be any effects from that then they are unlikely for a few weeks yet.

So it is quite possible that we will still have to go through an atlantic sequence as a backlog of positive zonal winds are piped through. The METO update ahead does reflect that possibility in terms of their expectation of atlantic influence finally returning eventually. Clearly though the gradual transition suggestion means that the block is going to be very stubborn, much as we already know!

Yeah thats what the GFS ensembles suggest as well however over and over and over again this winter have under-estimated the staying power of the upper high that has been to our N/NW/NE this winter, I see no reason why this should change given nothing much is going to change.

As for the MMW and the state of the Stratosphere, worth remembering the conditions are already well embedded and I suspect that if it does happen it may only take a week or two past any MMW to feel the effects, but we shall see.

Finally the most likely way any easterly will end quickly in the set-up that is progged is another attack from the SW...

[chionomaniac]

Yeah thats what the GFS ensembles suggest as well however over and over and over again this winter have under-estimated the staying power of the upper high that has been to our N/NW/NE this winter, I see no reason why this should change given nothing much is going to change.

As for the MMW and the state of the Stratosphere, worth remembering the conditions are already well embedded and I suspect that if it does happen it may only take a week or two past any MMW to feel the effects, but we shall see.

Finally the most likely way any easterly will end quickly in the set-up that is progged is another attack from the SW...

Presently, nothing is embedded KW. What we have is a very favourable stratospheric forecast. However, I do think a big stratosphere event is quite likely. We are likely to see an initial benefit from the position of the PV and maybe longer term benefits from potential northern blocking but we will have to wait and see.

[kold weather]

Sorry I didn't make that very clear, I meant embedded synoptics in the fact we have a strong upper high placed near the UK and global teleconnections are pretty stale and thus embedded with cut-off lows still being forced SE. As you say the Stratopshere hasn't started to warm up yet and also as you say we have got a decent starting point.

[chionomaniac]

Sorry I didn't make that very clear, I meant embedded synoptics in the fact we have a strong upper high placed near the UK and global teleconnections are pretty stale and thus embedded with cut-off lows still being forced SE. As you say the Stratopshere hasn't started to warm up yet and also as you say we have got a decent starting point.

I am superstitious KW, and do not want to jinx any MMW before it actually occurs!

[Eugene]

The warmest day in the so called mild snap.

http://www.wetterzentrale.de/pics/Rtavn10217.png

I remember when i was a lad that being rather cold

[derrylynne]

I don't know which model or sum of models the MetO are using for their long term outlook but they are not seeing much cold - just colder than average (although I guess that could mean anything from rather could to extreme cold)

'During the first part of the week there will be one or two wintry showers here and there, although most places will be dry with colder than average temperatures, icy stretches and areas of mist and freezing fog. Then later in the week it currently looks likely that a mixture of rain, sleet and snow will encroach from the southwest, with less cold conditions edging into western and northwestern areas. Then over the weekend and during the second week we are currently expecting a gradual transition to nearer normal temperatures across all areas as a southerly or southwesterly airflow becomes established across the United Kingdom. There will be rain, sleet and hill snow at times, although confidence on the timing of this transition to milder weather is currently only low.

They are then going with what is shown on the GEFS control run rather than the OP

So going by the meto's long range record we can take it the opposite is true. To be honest I have no confidence in the Meto's forecasts at all beyond 4 days. As has been said the guys on here do much better more often. The trick is to pick up a trend, and as far as I am concerned that is about all you can do beyond 7 days.

[k19]

Sorry if thi is a bit off topic, but why would scandinavean high pressure the charts are showing bring any snow?

[Osbourne One-Nil]

As has been said the guys on here do much better more often.

With respect to everyone who makes a forecast on this forum (well, almost everyone) I wonder if that's actually true? I've been around here a long time, and I quickly lost count of the times something's been promised and has failed to be delivered in any way, shape, or form. Yes, we all remember the time x said it would be cold in a fortnight's time, and it was cold in a fortnight's time. But equally, there are hundreds upon hundreds of occasions when the opposite is true. I also think that an unfair emphasis is placed on their forecasting for one particular weather-type; snow. It's not the Met Office's remit to ensure their forecasting doesn't upset those of us for whom snow is the most exicting things in their lives, and I imagine they're no better or worse at forecasting snow than any other weather type.

I'm not against anyone on here, and I'm no great defender of the Met Office, but I really don't get the criticism they get, because I bet you 99/100, the mid-range forecasting is a lot more accurate than anyone's on here.

[conor123]

It's looking increasingly likely that were just see a 3 day (4/5 day in South-West) mild spell, considering in past winters we've had to look for 36hours topplers to get cold spells interspersed between weeks of mild weather this is great news, things have completely flipped around and for Central and Eastern Areas temperatures will only be up to average at best anyway in this milder spell.

12z drags very cold air back across England as early as Tuesday.

[k19]

It's looking increasingly likely that were just see a 3 day (4/5 day in South-West) mild spell, considering in past winters we've had to look for 36hours topplers to get cold spells interspersed between weeks of mild weather this is great news, things have completely flipped around and for Central and Eastern Areas temperatures will only be up to average at best anyway in this milder spell.

12z drags very cold air back across England as early as Tuesday.

The mild could be the blip or the cold could be the blip, for all we know in a weeks time we could be in a prolonged mild spell, although i much prefer your prediction

[NL]

I'm betting on the big blue beast...

[ANYWEATHER]

I'm betting on the big blue beast...

I like it!!

[fear sneachta]

Until what is showing at +168 is at +72.

Let me put it this way the sign I used was spot on for 1987, 1991. This is why i've remained confident because the sign is even more evident than Jan 87. I would go as far to say i've never seen anything like it and neither has my mother who was the first to mention it to me!

What do you mean TEITS? Do you mean the GFS? What is remarkable about this? Forgive me, I'm fairly new to reading models. This is GFS + 168

Edited January 13, 2010 by fear sneachta

[PB22]

With respect to everyone who makes a forecast on this forum (well, almost everyone) I wonder if that's actually true? I've been around here a long time, and I quickly lost count of the times something's been promised and has failed to be delivered in any way, shape, or form. Yes, we all remember the time x said it would be cold in a fortnight's time, and it was cold in a fortnight's time. But equally, there are hundreds upon hundreds of occasions when the opposite is true. I also think that an unfair emphasis is placed on their forecasting for one particular weather-type; snow. It's not the Met Office's remit to ensure their forecasting doesn't upset those of us for whom snow is the most exicting things in their lives, and I imagine they're no better or worse at forecasting snow than any other weather type.

I'm not against anyone on here, and I'm no great defender of the Met Office, but I really don't get the criticism they get, because I bet you 99/100, the mid-range forecasting is a lot more accurate than anyone's on here.

I agree 100% OON. The Met Office are the professionals at this game, and I would bet that their accuracy rates are a lot higher than anyone else's. Sadly, most people here and elsewhere only tend to focus on cold and snow, thus failing to take into account all the millions of forecasts that, shock horror, don't include cold and snow! Met Office forecasts aren't scrutinised in spring, summer and autumn to the extent that they are in winter and thus a lot of their work is by and large un-noticed.

Anyway, back to models...

The 12Z GFS is a good run for the cold lovers as we are soon back into a colder easterly flow next week after a milder weekend:

http://www.wzkarten....s/Rtavn661.html

http://www.wzkarten....s/Rtavn662.html

By midweek there are some reasonable cold uppers across the country:

http://www.wzkarten..../Rtavn1621.html

http://www.wzkarten..../Rtavn1622.html

UKMO 12Z isn't too dis-similar to the GFS at T+120, although it still has us under a SW'ly:

http://www.meteociel...20-21.GIF?13-17

By T+144 its very much game on:

http://www.meteociel...44-21.GIF?13-17

Once we get into GFS FI, we soon lose the easterly again, and this is another trend that the GFS ensembles have been hinting at so far.

http://www.wzkarten.de/pics/Rtavn2401.html

Edited January 13, 2010 by Paul B