General Model Output Discussion

[La Bise]

I love the difference between the 18z and 0z temp chart above, it went for 10c for my area to...ooh, -1c...

[David-kig]

nae showing show turning bk to rain in devon a cornwall by wednesday

[Guest]

nae showing show turning bk to rain in devon a cornwall by wednesday

From the run I'm looking at it only turns back to rain around the coast. Unless you've got a different (newer?) run than me to look at?? Quite hard to tell exactly what is going on, but it is not wall to wall rain!

[snowingtequila]

Just heard Philip Eden on radio 4 from the royal meterelogical society state that by the weekend much warmer temperatures will sweep across the whole country, this doesn't seem to tie in with the models to me, I didn't think it was sop clear cut, have I missed something?

[ANYWEATHER]

Morning! WEll the gfs wants to bring milder air for a time during this coming weekend but thats all in FI! Philip Eden thoughts may be somewhat correct but it would be good to hear what he says in a couple of days time,perhaps he will be saying something different! but judging by the ecm its not going to warm up at all if anything a reload of Artic air and even the gfs keeps that cold block flirting with the uk. So this coming week will bring more Wintry weather and we all have to remember that any milder weather is all FANTASY ISLAND

[Frosty.]

The 00z models are showing a change to milder by the weekend with a rapid thaw and heavy rain pushing east but until then it will stay cold with temps only a few degrees above freezing with some snow around, mostly in the south and west with southwest england & south wales in for heavy, drifting snow tomorrow with temps around freezing. Whilst the models are slowly firming up on the less cold, milder end to this week, there is a suggestion it could become colder again during next week but i'm not holding out much hope for that to be honest.

[derrylynne]

Morning! WEll the gfs wants to bring milder air for a time during this coming weekend but thats all in FI! Philip Eden thoughts may be somewhat correct but it would be good to hear what he says in a couple of days time,perhaps he will be saying something different! but judging by the ecm its not going to warm up at all if anything a reload of Artic air and even the gfs keeps that cold block flirting with the uk. So this coming week will bring more Wintry weather and we all have to remember that any milder weather is all FANTASY ISLAND :blink:

Where in Fantasy land is the milder air. I think it is plain to see on most the charts - it is going to turn warmer with rain rather than sleet after a couple of days. I am sure many people will be happy with that one too..It is no good wishing for snow - look at the charts and read what is there not what you wish...

Edited January 11, 2010 by derrylynne

[phil nw.]

The 00z models are showing a change to milder by the weekend with a rapid thaw and heavy rain pushing east but until then it will stay cold with temps only a few degrees above freezing with some snow around, mostly in the south and west with southwest england & south wales in for heavy, drifting snow tomorrow with temps around freezing. Whilst the models are slowly firming up on the less cold, milder end to this week, there is a suggestion it could become colder again during next week but i'm not holding out much hope for that to be honest.

Morning Frosty,

Yes an increasing trend towards a milder spell by the weekend as the output eases the Scandi high away eastwards.

http://www.wetterzen...s/Rtavn1441.png

http://www.wetterzen...cs/Rukm1441.gif

http://www.wetterzen...cs/Recm1441.gif

http://www.wetterzen...cs/Rgem1441.gif

The cold continental flow gradually becoming more and more modified by the Atlantic lows.

Edited January 11, 2010 by phil n.warks.

[derrylynne]

I must admit to some surprise that the MetO are progging heavy snow off the advancing front, rather than sleety-rain, but they may be absolutely right.

This is marginal indeed. Who'd be a professional forecaster when the slightest change brings the national scrum down on top of you?

So am I West. In fact I will be more than surprised if tomorrows offering comes in as snow for all but the high ground given the marginal warmer conditions at the moment. My feeling is they are covering themselves, better to play safe than not say anything and get caught out with uproar from the public that they were not warned.

[Frosty.]

Morning Frosty,

Yes an increasing trend towards a milder spell by the weekend as the output eases the Scandi high away eastwards.

http://www.wetterzen...s/Rtavn1441.png

http://www.wetterzen...cs/Rukm1441.gif

http://www.wetterzen...cs/Recm1441.gif

http://www.wetterzen...cs/Rgem1441.gif

The cold continental flow gradually becoming more and more modified by the Atlantic lows.

Hi phil,

Yes there is increasing confidence now for a significant rise in temps beyond friday, so the main hazard then will be flooding due to rapid snow melt and heavy rain, a truly awful combination but the likely outcome. There is no point in anyone kidding themselves that some miracle will occur to stop the milder air arriving this weekend and into the start of next week.

[ANYWEATHER]

Where in Fantasy land is the milder air. I think it is plain to see on most the charts - it is going to turn warmer with rain rather than sleet after a couple of days. I am sure many people will be happy with that one too..It is no good wishing for snow - look at the charts and read what is there not what you wish...

Not wishing, just realistic, even by the weekend temps still surpressed ok a slow thaw unless you call 4 or 5 celcius warm!

[Weather-history]

Hi phil,

Yes there is increasing confidence now for a significant rise in temps beyond friday, so the main hazard then will be flooding due to rapid snow melt and heavy rain, a truly awful combination but the likely outcome. There is no point in anyone kidding themselves that some miracle will occur to stop the milder air arriving this weekend and into the start of next week.

There is a slow thaw under way now, so some areas could get away with it come weekend as most of the snow could have melted by then but other areas such as those next to rivers could have problems. The Pennines have been virtually snow covered for close to a month and a rapid melt here will feed into the rivers and there could be real problems.

[snowingtequila]

Hi phil,

Yes there is increasing confidence now for a significant rise in temps beyond friday, so the main hazard then will be flooding due to rapid snow melt and heavy rain, a truly awful combination but the likely outcome. There is no point in anyone kidding themselves that some miracle will occur to stop the milder air arriving this weekend and into the start of next week.

because it is such a slow thaw I think flooding to be unlikely to be a problem, I am not convinced by the weekend and after the weekend the models are not united in showing a continuing atlantic control of the weather

[johnholmes]

Yes, looking at the 3 models for T+144 and all are pretty well agreed that, at last, a chink is showing in the blocking, allowing milder air over the country, milder being the operative word. Not many double figures being progged, just yet away from the far south west. It should at least get rid of most of the snow and ice from much of England and Wales but I’m not so sure about parts of Scotland especially the hillier areas further north.

Are we then going to be in a run of south westerlies for a time?

Nope- or so it seems. You only have to turn the page from T+168 on the 2 models out at that range and what reappears? The Scandinavian high it would seem-on both models. How realistic is this? By T+240 they both go their separate ways. GFS having a rather indeterminate looking set of charts until later in its FI far reaches when it brings the high back. ECMWF at T+240 has brought in another deepish low with the high retreating somewhat further east.

Which will be right? I doubt we will know that answer for most of this week as the models grapple with teleconnections that are starting to show less northern blocking than for some time but! But what? Well I doubt that mild will be the main word for much of the remainder of this winter, perhaps 50% but not the dominant one. I suspect that cold will reappear at some stage well before official winter ends.

In fact even well before then, in spite of AO and NAO showing strong signs of both going +ve it’s a far from clear picture. The remainder of the official winter period, from this week on, to me, seems pretty finely balanced, some pointers to less cold taking over but some pointing to much greater uncertainty with the possibility of deeper cold returning before this month is out.

[stewfox]

Absolutely no chance of a NW,ly im afraid.

The evidence for the strong Scandi HP is overwhelming at the moment. This isn't just based on the ECM/JMA either. Look at the 12Z SLP ensembles for Moscow/Oslo. Quiet incredible SLP ensembles.

http://charts.netwea...2/prmslOslo.png

http://charts.netwea...prmslMoscow.png

I strongly disagree with some of the comments about it turning milder with the atlantic returning. We may find SW/W areas see a brief period of less cold weather before the Scandi HP brings back colder temps.

Are you holding on to this view given JH comments today.

The papers seem to be all over the place the BBC go out T18 (They are doing T240 a few days ago!).

My Net weather forecast for my area Bicester give max temps to 1c till end Friday so clearly updates haven't been model in.

Are we still in T24/T48 now casting or are the trends from this morning nailing a more 'milder' set up up to T168.Milder being 4/5c rather then 9/10c.

I always appreciate your views.

[chionomaniac]

Yes, looking at the 3 models for T+144 and all are pretty well agreed that, at last, a chink is showing in the blocking, allowing milder air over the country, milder being the operative word. Not many double figures being progged, just yet away from the far south west. It should at least get rid of most of the snow and ice from much of England and Wales but I’m not so sure about parts of Scotland especially the hillier areas further north.

Are we then going to be in a run of south westerlies for a time?

Nope- or so it seems. You only have to turn the page from T+168 on the 2 models out at that range and what reappears? The Scandinavian high it would seem-on both models. How realistic is this? By T+240 they both go their separate ways. GFS having a rather indeterminate looking set of charts until later in its FI far reaches when it brings the high back. ECMWF at T+240 has brought in another deepish low with the high retreating somewhat further east.

Which will be right? I doubt we will know that answer for most of this week as the models grapple with teleconnections that are starting to show less northern blocking than for some time but! But what? Well I doubt that mild will be the main word for much of the remainder of this winter, perhaps 50% but not the dominant one. I suspect that cold will reappear at some stage well before official winter ends.

In fact even well before then, in spite of AO and NAO showing strong signs of both going +ve it’s a far from clear picture. The remainder of the official winter period, from this week on, to me, seems pretty finely balanced, some pointers to less cold taking over but some pointing to much greater uncertainty with the possibility of deeper cold returning before this month is out.

I have changed my thoughts since yesterday John and would have to agree with your analysis. Crucially the planned resplit of the polar vortex is not going to occur. This means that there will be no vortex segment dropping into NW Siberia which would have stopped the Scandi High from drifting Eastward. This drift is eventually going to allow inroads from the westerly trough and milder weather to ensue. However this mild interlude may not last too long and I am sure the Scandi high will reappear.

Edited January 11, 2010 by chionomaniac

[Richard Lake]

Looking at the 16-day Net-Weather UK Forecast shows GFS is far from certain regarding next weekend and already shows backtracking. Once again I repeat my thoughts from last night - this weekend's weather just gone was fairly incorrect from a week out so doesn't give me much confidence in the models at the moment. As GP posted in the In-Depth thread, the models are not going to be very consistent at all this week so I suggest everyone take a week-off from this obsession with the weather.

[MisfitDog3]

It's all a bit of a mess really. I'm not really convinced by any of the medium to long term forecasts at present. Some odd 'jumps' from one state of affairs to another on the 'GFS' without any real natural progression evident, that Scandi High, on tow other models, just looks too big and misplaced and what is supposed to be happening on the western side of it just seems devoid of any real detail. This all needs to shake down over the next 48 hours...

[Pennine Ten Foot Drifts]

There is a slow thaw under way now, so some areas could get away with it come weekend as most of the snow could have melted by then but other areas such as those next to rivers could have problems. The Pennines have been virtually snow covered for close to a month and a rapid melt here will feed into the rivers and there could be real problems.

Yes, it's quite difficult to imagine a warm-up at this moment in time, but that is certainly looking more and more likely. Very good summary from J-H though, and I'm trying to remember what the charts were showing just before Xmas when the mid-range was progging a warm up then, which actually only materialised for a few days. In fact, for my location, it was only the 2-3 days around Boxing Day where the precipitation was a sleety rainy mix, other than that everything that's fallen out of the sky since mid-December up to now has been snow, which is pretty impressive really.

[TEITS]

Are you holding on to this view given JH comments today.

The papers seem to be all over the place the BBC go out T18 (They are doing T240 a few days ago!).

My Net weather forecast for my area Bicester give max temps to 1c till end Friday so clearly updates haven't been model in.

Are we still in T24/T48 now casting or are the trends from this morning nailing a more 'milder' set up up to T168.Milder being 4/5c rather then 9/10c.

I always appreciate your views.

My view remains unchanged this morning.

For starters the front that will bring snow to the SW will most likely align NW-SE probably from N Wales to W London. This means possible snow for the SW/W Midlands/Wales but is unlikely to spread snow further E and most likely just die away. Beyond and SW England/Wales will see a brief milder interlude but those in the E are likely to remain cold but slightly less cold than recently i.e max temps around 3-5C. Beyond this week and the most likely outcome is turning colder from the E and with this comes the risk of snow showers once again.

Have to say im surprised at some of the comments this morning. In my opinion forecasting isn't about relying on the models to tell you whats going to happen. Due to the synoptics i.e Scandi HP vs Atlantic you need to use abit of forecasting instinct which is why a 1050mb Scandi HP will put up much more of a fight than the models currently suggest. Look out from around Wed onwards when the models will show the Scandi HP being more influencial with the atlantic making less progress.

[D KARLSON]

[

In fact even well before then, in spite of AO and NAO showing strong signs of both going +ve it’s a far from clear picture. The remainder of the official winter period, from this week on, to me, seems pretty finely balanced, some pointers to less cold taking over but some pointing to much greater uncertainty with the possibility of deeper cold returning before this month is out.

''''''''''''''''''''''''''''''''''''''

The details of any change at the mo will be hard to pin down and a few surprises along the line are likely in my opinion ,but the main key to any changes is how the energy trying to push in from the west interacts with this very cold and long established cold pool over europe.

Indications on the cold returning from the east at some point will always be on the cards as the cold air is only likely to be pushed around rather than cleared out the way almost like a boxing match ,how this will pan out is purely conjecture.

Going by previous cold winters will perhaps help understand how this one will go but dteails will always be different

but if you were a BETTING man you would at best get even odds on cold returning !!!!!!

[loadsa]

It's all a bit of a mess really. I'm not really convinced by any of the medium to long term forecasts at present. Some odd 'jumps' from one state of affairs to another on the 'GFS' without any real natural progression evident, that Scandi High, on tow other models, just looks too big and misplaced and what is supposed to be happening on the western side of it just seems devoid of any real detail. This all needs to shake down over the next 48 hours...

Medium to long term!!

They cant get the short term right at the moment up until late Saturday night they were forecasting some sort of armageddon for the south east the following day.

I posted this in the wales thread

Netweather/BBC forecast both giving sleet tomorrow for Caerphilly

Met Office giving snow until Wednesday then turning to sleet

Thought BBC took their guidance from the met

So who will be right, can see this ending up being a nothing event down the south

At the moment they are all giving a dry day but looking out my window I have had more snow in the last hour than I had all day yesterday here in S Wales

[weather eater]

All seems pretty clear to me, the general trend right out to the mid-range has a strong Scandi/Euro high, with the UK on the edge of this feature, this means we will stay in a strong at times, SWly maybe southerly at times flow, while not very mild, not cold either. I sense a fairly rapid thaw after mid week, indeed despite snow falling from the sky here, the ground cover is disappearing quite fast. I’m not really to sure where some posters are getting the idea that FI is really close at the moment, in detail maybe but not in the general picture, same as always in fact.

[Guest North Sea Snow Convection]

A less cold pattern looks fairly certain now, however there remains a lot of uncertainty about how much strength the regrouping polar vortex may attain in terms of pushing atlantic weather past the meridian.

The models do continue to suggest that we could be in the middle of the sandwich between the systems to our west and the blocking to our east. On that basis perhaps we will merely see more average temps for January rather than above average.

Whilst any real mild weather may not occur, I also think the chances of another push from the north east in terms of a reload of upper cold have rather faded - at least for the shorter term. It could be towards months end/into February we start to see this occur. Stratosphere watch will give good clues to this as we see if the emerging signs of an MMW keep developing. Much as we observed exactly a year ago.

[Weather-history]

GFS looks January 1996ish with a block to the east, a trough in the Atlantic and the UK in between the two.